WO2024016029A1 - X-ray rotating anode analysis system - Google Patents

Abstract

The invention relates to an X-ray rotating anode analysis system (54) for analysing a used X-ray rotating anode (33) having a circumferential focal track (40) on a surface section thereof. The X-ray rotating anode analysis system (54) has a positioning device (56) for the X-ray rotating anode (33), an imagine-capturing unit (58), and a data processing unit (64) coupled to the image-capturing unit (58). The positioning device (56) and the image-capturing unit (58) are designed in such a way that the X-ray rotating anode (33) can be positioned as an individual component in a predetermined position relative to the image-capturing unit (58). The image capturing unit (58) and the data processing unit (64) are designed in such a way that a three-dimensional elevation profile of a surface section of the X-ray rotating anode (33) in the region of its focal track (40) can be detected by the image-capturing unit (58) and the data processing unit (64), and, from the detected three-dimensional elevation profile or from a part thereof, an expected radiant power or a characteristic variable for same of the X-ray rotating anode (33) can be determined by the data processing unit (64).

Description

=10°). Damit werden aufgrund von Besonderheiten des 3-dimensionalen Höhenprofils und dessen Auflösung theore- tisch mögliche Spitzen der lokal von einzelnen Erzeugungspunkten emittierten Strah- lungsleistung, die zu lokalen Verfälschungen führen würden, vermieden (beispielsweise an in Röntgenstrahlungs-Austrittsrichtung lokal sehr steil abfallenden Flanken der Ober- flächenstruktur der Brennbahn-Oberfläche). Im Folgenden wird unter Bezugnahme auf die Figuren 6, 7 und 8 erläutert, wie für jeden Erzeu- gungspunkt von Röntgenstrahlung die Absorption durch das Brennbahn-Material unter Einbe- ziehung der lokalen Oberflächenmodifikationen gemäß dem 3-dimensionalen Höhenprofil er- mittelt wird: In Fig.8 ist in dem obersten Diagramm ein beispielhaftes Linienprofil einer ge- brauchten Brennbahn-Oberfläche, aufgetragen als Höhe (Einheit: Millimeter) (s. „height [mm]“ in dem Diagramm) über der y-Richtung (Einheit: Millimeter) (s. „y[mm]“ in dem Diagramm), dargestellt. Es ist beispielsweise aus einem Schnitt des in Fig.5 gezeigten 3-dimensionalen Hö- henprofils entlang der Röntgenstrahlungs-Austrittsrichtung y erzeugbar. Die Figuren 6 und 7 zeigen jeweils schematisch einen Ausschnitt derartiger Linienprofile von Brennbahn-Oberflä- chen. In Fig.6 ist zunächst die Situation einer perfekt glatten Brennbahn-Oberfläche 92, die mit einem Neigungswinkel α=10° (in Fig.6 und 7 zur Veranschaulichung größer dargestellt) gegen- über der y-Richtung geneigt ist, dargestellt. Anhand von zwei beispielhaften Elektronen 94, 96, die mit zwei unterschiedlichen y-Koordinaten auf die Brennbahn-Oberfläche 92 auftreffen und (vereinfachend dargestellt) entsprechend der mittleren Erzeugungstiefe d_e- von Röntgenstrah- lung bis zu dem jeweiligen Erzeugungspunkt 98 eindringen, ist die von der erzeugten Röntgen- strahlung in Röntgenstrahlungs-Austrittsrichtung (y-Richtung) zurückgelegte Weglänge d_x-ray durch das Brennbahn-Material dargestellt. Unabhängig vom Auftrittsort der Elektronen inner- halb des Brennflecks ist die zurückgelegte Weglänge durch die nachfolgende Formel ermittel- bar:

Bei d_e-=1,6 μm und α=10° ergibt dies eine konstante zurückgelegte „theoretische Weglänge“ d_x-ray=9,07 μm. D.h. die erzeugte Röntgenstrahlung wird bei einer perfekt glatten Brennbahn- Oberfläche 92 zunächst über eine Weglänge d_x-ray von konstant 9,07 μm einer Filterung durch das Brennbahn-Material unterzogen, bevor sie aus der Brennbahn-Oberfläche austritt. An- schließend wird sie durch Filter 102 gefiltert, bevor sie (falls keine weiteren Hindernisse oder zu durchstrahlenden Objekte im Strahlungsgang sind) auf einen Detektor 104 trifft. Beispielsweise kann ein Filter aus Borsilikat-Glas von 2,5 mm Dicke (z.B. als Austrittsfenster) und ein Alumi- nium-Filter von 2 mm in dem Berechnungsmodell angesetzt werden. Bzgl. der Filterung durch das Brennbahn-Material kann in Bezug auf Wolfram-Rhenium-Brennbahnen (mit einem über- wiegenden Anteil an Wolfram) vereinfachend eine Filterung durch reines Wolfram (W) ange- setzt werden, da sich Wolfram (W) und Rhenium (Re) in Ihrer Ordnungszahl und Dichte nur ge- ringfügig unterscheiden. Die bei einer perfekt glatten Brennbahn-Oberfläche auftretende Ab- sorption durch das Brennbahn-Material (über eine Weglänge von jeweils 9,07 μm) sowie die Filterung durch die Filter 102 wird als Basis-Filterung bezeichnet. Die bei einer solch perfekt glatten Brennbahn-Oberfläche zu erwartende potenzielle Basis- Strahlungsleistung eines Linienprofils bzw. einer y-Koordinate wird dabei als Vergleichswert herangezogen. Insbesondere wird unter Zugrundelegung des oberhalb beschriebenen Aus- gangsspektrums die Absorption durch das Brennbahn-Material über die Weglänge von 9,07 μm sowie die Filterung durch die Filter 102 zunächst die für eine einzelne y-Koordinate zu erwar- tende potenzielle Basis-Strahlungsleistung in Röntgenstrahlungs-Austrittsrichtung ermittelt. Dies erfolgt insbesondere Software-unterstützt (z.B. mit SpekCalc pro 1.1, einer bzgl. des theo- retischen Ansatzes von Gavin Poludniowski und Phil Evans am „The Institute of Cancer Rese- arch“, London, UK und bzgl. der graphischen Benutzeroberfläche von Francois deBlois, Guillaume Landry und Frank Verhaegen an der Mc Gill University, Montreal, Kanada entwickel- ten Software; erhältlich derzeit über www.spekcalc.weebly.com). Dabei ist die Software vor- zugsweise derart eingerichtet, dass sie zunächst für eine einzelne y-Koordinate des Linienprofils (wellenlängenabhängig) die Reduktion/Filterung des Ausgangsspektrums ermittelt (da die Stärke der Reduktion/Filterung abhängig von der Wellenlänge bzw. Energie der Photonen ist), um daraus ein „potenzielles Basis-Spektrum“ zu erhalten („potenziell“, da noch nicht die Elekt- ronen-Intensitätsverteilung und Größe des Brennflecks berücksichtigt), dessen Intensitätsver- teilung gegenüber dem Ausgangsspektrum (wellenlängenabhängig) reduziert ist. Anschließend wird vorzugsweise für eine einzelne y-Koordinate eine „potenzielle Basis-Strahlungsleistung“ ermittelt, die sich aus der Summe bzw. Integration der Strahlungsleistungen über die verschie- denen Wellenlängen des nach der Basis-Filterung erhaltenen potenziellen Basis-Spektrums ergibt. Da vorliegend von einer perfekt glatten Brennbahn-Oberfläche ausgegangen wird und nur das „potenzielle“ Basis-Spektrum sowie die „potenzielle“ Basis-Strahlungsleistung betrach- tet werden (d.h. die Elektronen-Intensitätsverteilung und Größe des Brennflecks bisher noch keine Berücksichtigung finden), sind diese über die verschiedenen y-Koordinaten eines Linien- profils und entsprechend auch in Umfangsrichtung für verschiedene Linienprofile konstant. Demgegenüber weist die Brennbahn-Oberfläche der Fig.7 Oberflächenstrukturen bzw. Oberflä- chenmodifikationen 100 auf, wie sie beispielsweise bei einer gebrauchten Röntgendrehanode auftreten (im Übrigen ist Fig.7 entsprechend wie Fig.6 aufgebaut und gleiche Bauteile/Ab- schnitte sind mit gleichen Bezugszeichen versehen). Gemäß dem Berechnungsmodell wird nun für jeden Erzeugungspunkt 98 von Röntgenstrahlung, d.h. für jede y-Koordinate entlang der y- Richtung (Röntgenstrahlungs-Austrittsrichtung) des Linienprofils unter Berücksichtigung der Oberflächenmodifikationen gemäß dem 3-dimensionalen Höhenprofil die tatsächlich durch das Brennbahn-Material zurückgelegte Weglänge d‘_x-ray (in y-Richtung) ermittelt, wie dies in Fig.7 veranschaulicht ist. Dabei sind zur Ermittlung dieser „tatsächlichen Weglänge“ d‘_x-ray ggf. auch Teil-Weglängen zu addieren, falls die Röntgenstrahlung von einem Erzeugungspunkt ausgehend in y-Richtung zunächst aus der Brennbahn-Oberfläche austritt, dann aber nochmals (z.B. auf- grund einer lokalen Erhebung) in das Brennbahn-Material eintritt (einmalig oder mehrmalig), bevor sie dann endgültig in den freien Bereich außerhalb des Brennbahn-Materials gelangt. Diese Ermittlung und auch die weiteren Berechnungsschritte (soweit nicht abweichend angege- ben) erfolgen vorzugsweise Software-unterstützt mittels einer entsprechend eingerichteten Software (z.B. durch Matlab R2017b 64bit; derzeit erhältlich unter www.mathworks.com). Hierzu wird vorzugsweise das jeweilige Linienprofil (wie z.B. in Fig.8 in dem obersten Diagramm gezeigt) in die Software importiert. Alternativ wird eines oder mehrere 3-dimensionale Höhen- profil(e) in die Software importiert und anschließend werden die in radialer Richtung verlaufen- den Linienprofile gemäß der obigen Vereinfachung/Herangehensweise Nr.3 generiert. Ferner sind jeweils der Neigungswinkels (hier: α=10°) und die mittlere Erzeugungstiefe von Röntgen- strahlung (hier: d_e-=1,6 μm) zugrunde zu legen, um dann, wie in Fig.7 veranschaulicht ist, für jede y-Koordinate des jeweiligen Linienprofils die von dem jeweils zugehörigen (um d_e- in z- Richtung nach unten in das Brennbahn-Material versetzten) Erzeugungspunkt ausgehende und in y-Richtung durch das Brennbahn-Material zurückgelegte tatsächliche Weglänge d‘_x-ray zu er- mitteln. Dies kann mittels der Software z.B. durch Vergleich des ursprünglichen Linienprofils (maßgeblich für die Brennbahn-Oberfläche) und eines um d_e- in z-Richtung nach unten in das Brennbahn-Material versetzten, im Übrigen identischen Linienprofils (maßgeblich für den Er- zeugungspunkt) erfolgen, um dann die tatsächlich zurückgelegten Weglängen in y-Richtung in Abhängigkeit von der jeweiligen y-Koordinate des jeweiligen Linienprofils zu ermitteln. An- schließend wird eine zusätzliche Weglängenverteilung f_add(y) durch Subtraktion der theoreti- schen Weglänge d_x-ray von der tatsächlichen Weglänge d‘_x-ray(y) wie folgt ermittelt:

Soweit für eine y-Koordinate die tatsächliche Weglänge d‘_x-ray(y) von theoretischen Weglänge d_x-ray abweicht, ergibt sich hieraus eine von der oben erläuterten Basis-Filterung abweichende tatsächliche Filterung. Durch auftretende Oberflächenmodifikationen ergibt sich für die meis- ten y-Koordinaten eine erhöhte tatsächliche Weglänge d‘_x-ray(y) im Vergleich zu der theoreti- schen Weglänge d_x-ray (d.h. Werte > 0 für f_add). Für einen gewissen Anteil der y-Koordinaten ist die tatsächliche Weglänge d‘_x-ray(y) hingegen reduziert (d.h. Werte < 0 für f_add), wobei dann zu- mindest die Mindestweglänge von 5 μm gemäß der obigen Vereinfachung/Herangehensweise Nr.5 einzusetzen ist (s. Zeile 2 der Gleichung (2)). In Fig.8 ist in dem zweiten Diagramm die zu- sätzliche Weglängenverteilung, aufgetragen als zusätzliche Weglänge fadd(y) (Einheit: Mikrome- ter bzw. μm) („f_add(y) [μm]“ in dem Diagramm) über der y-Richtung (Einheit: Millimeter) (s. „y[mm]“ in dem Diagramm), die sich konkret für das in Fig.8 oben dargestellte Linienprofil ergibt, dargestellt. Danach erfolgt, weitgehend entsprechend wie für die perfekt glatte Brennbahn (vorzugsweise Software-unterstützt, z.B. mit SpekCalc pro 1.1; s. oben), dass zunächst einmal allgemein die (wellenlängenabhängige) Reduktion/Filterung des Ausgangsspektrums als Funktion in Abhän- gigkeit von f_add (und noch nicht konkret für verschiedene y-Koordinaten) ermittelt wird, um dar- aus ein „potenzielles tatsächliches Spektrum“ als Funktion in Abhängigkeit von f_add zu erhalten, dessen Intensitätsverteilung gegenüber dem Ausgangsspektrum reduziert ist. Anschließend wird eine „potenzielle tatsächliche Strahlungsleistung“, die sich aus der Summe bzw. Integra- tion der Strahlungsleistungen über die verschiedenen Wellenlängen des potenziellen tatsächli- chen Spektrums ergibt, als Funktion in Abhängigkeit von f_add ermittelt. Als weiterer Schritt wird (vorzugsweise wiederum Software-unterstützt, z.B. mit SpekCalc pro 1.1; s. oben) das Verhält- nis f_red dieser potenziellen tatsächlichen Strahlungsleistung relativ zu der potenziellen Basis- Strahlungsleistung (ermittelt wie oberhalb angegeben) als Funktion in Abhängigkeit von f_add ge- bildet. Dieses ermittelte Verhältnis f_red(f_add) gibt folglich an, wie stark sich die potenzielle tat- sächliche Strahlungsleistung eines Entstehungspunktes von Röntgenstrahlung relativ zu der po- tenziellen Basis-Strahlungsleistung einer perfekt glatten Brennbahn-Oberfläche in Abhängigkeit von der zusätzlichen Weglänge f_add, welche die Röntgenstrahlung von dem Entstehungspunkt aus zurücklegen muss, verändert. Dieses ermittelte Verhältnis f_red(f_add) kann insbesondere mit einer Funktion, vorzugsweise mit einer doppelt exponentiellen Funktion (d.h. mittels einer Summe zweier Exponentialfunktionen), gefittet werden. Ausgehend von dem minimalen Wert (vorliegend -4,07 μm) ist sie für negative Werte der zusätzlichen Weglänge f_add größer als 1, fällt dann kontinuierlich ab und erreicht für f_add=0 exakt den Wert 1. Für positive Werte der zusätzli- chen Weglänge f_add ist sie kleiner 1 und geht für zunehmend größere Werte der zusätzlichen Weglänge f_add gegen null. Diese Funktion wird nun, vorzugsweise wiederum Software-unter- stützt (z.B. mit Matlab R2017b 64bit; s. oben), konkret auf die zusätzliche Weglängenverteilung f_add(y), wie sie für das Linienprofil unter Anwendung von Gleichung (2) ermittelt wurde, ange- wendet, um daraus eine Emissionsverteilung f_emi(y) über die verschiedenen y-Koordinaten des Linienprofils zu erhalten, wie nachstehend in Gleichung (3) angegeben ist:

Die Emissionsverteilung f_emi(y) gibt dabei für die verschiedenen y-Koordinaten des Linienprofils das Verhältnis der potenziellen tatsächlichen Strahlungsleistung relativ zu der potenziellen Ba- sis-Strahlungsleistung an, wobei dieses Verhältnis bei y-Koordinaten mit zugehörigem negativen Wert von f_add (d.h. d‘_x-ray(y) < d_x-ray) größer als 1 und für positive Werte von f_add (d.h. d‘_x-ray(y) > d_x-ray) kleiner als 1 ist. Dies bedeutet, dass je größer die tatsächliche Weglänge d‘_x-ray im Verhält- nis zu der theoretischen Weglänge d_x-ray für den jeweiligen Erzeugungspunkt ist, desto niedriger ist das Verhältnis der potenziellen tatsächlichen Strahlungsleistung relativ zu der potenziellen Basis-Strahlungsleistung (d.h. desto mehr emittierte Strahlung wird absorbiert), und umge- kehrt. In Fig.8 ist in dem dritten Diagramm dieses Verhältnis bzw. diese Emissionsverteilung, aufgetragen als Emissionsverteilung f_emi(y) („f_emi(y) [-]“ in dem Diagramm) über der y-Richtung (Einheit: Millimeter) (s. „y[mm]“ in dem Diagramm), die sich konkret für die in Fig.8 in dem zweiten Diagramm dargestellte zusätzliche Weglänge f_add(y) ergibt, dargestellt. Schließlich ist nun noch, um nicht nur als „potenziell“ bezeichnete Größen zu vergleichen, in y- Richtung (d.h. entlang der radialen Richtung) die Elektronen-Intensitätsverteilung zu berück- sichtigen, da die an der jeweiligen y-Koordinate erzeugte Strahlungsleistung davon abhängt, ob und in welcher Intensität Elektronen auf diese y-Koordinate auftreffen. Beispielsweise sind aus diesem Grund Beschädigungen der Brennbahn-Oberfläche in radialer Richtung außerhalb des Brennfleck-Bereichs weniger kritisch, da an diesen Positionen keine Röntgenstrahlung erzeugt wird, während Beschädigungen im Bereich hoher Elektronen-Intensität besonders kritisch sein können, insbesondere wenn sie zu starken Abschattungen führen. Wie unter der Vereinfa- chung/Herangehensweise Nr.2 oberhalb erläutert wird, kann die Elektronen-Intensitätsvertei- lung bei Röntgendrehanoden durch ein lineares (in y-Richtung bzw. radialer Richtung verlaufen- des) Intensitätsprofil f_e-(y) beschrieben werden. Die Emissionsverteilung f_emi(y) ist durch dieses Intensitätsprofil f_e-(y) entsprechend zu gewichten, um für die jeweilige y-Koordinate das Ver- hältnis O(y) der „tatsächlichen Strahlungsleistung“ relativ zu der „Basis-Strahlungsleistung“ zu erhalten, wie in der nachstehenden Gleichung wiedergegeben ist:

Um dann das Verhältnis O_Linie der tatsächlichen Strahlungsleistung, die über das gesamte Linien- profil einer geschädigten Brennbahn-Oberfläche mit Oberflächenstrukturen emittiert wird, rela- tiv zu der zugehörigen Basis-Strahlungsleistung, die über das gesamte Linienprofil im Falle einer perfekt glatten Brennbahn-Oberfläche emittiert werden würde, zu erhalten, ist O(y) über die y- Koordinate zu integrieren, wie durch die nachstehende Gleichung dargestellt ist:

Auf diese Weise sind die Auswirkungen von Oberflächenstrukturen, die im Bereich eines konk- ret untersuchten Linienprofils einer geschädigten Brennbahn-Oberfläche auftreten, auf die emittierte Strahlungsleistung bewertbar. Insbesondere stellt O_Linie einen Kennwert über die Ab- schwächung der Strahlungsleistung durch Beschädigungen der Brennbahn-Oberfläche dar. Fer- ner können natürlich in entsprechender Weise eine Vielzahl von (jeweils radial verlaufenden und vorzugsweise in Umfangsrichtung um die Röntgendrehanode verteilten) Linienprofilen aus- gewertet werden. Dabei sind zum Einen Variationen, die in Umfangsrichtung der Röntgendreh- anode auftreten können, feststellbar. Ferner ist auch eine Gesamt-Strahlungsleistung durch Summation/Integration der für die einzelnen Linienprofile erhaltenen O_Linie-Werte ermittelbar. Die vorliegende Erfindung ist nicht auf die beschriebenen Ausführungsformen beschränkt. Bei- spielsweise kann alternativ zu der Vereinfachung/Herangehensweise Nr.2 (s. oben) bzgl. des Brennflecks und des Linienprofils auch eine Elektronen-Intensitätsverteilung über die be- troffene Fläche, d.h. eine Funktion f_e-(x,y) herangezogen werden. Dann sind entsprechend der Größe des Brennflecks eine Mehrzahl von nebeneinander liegenden Linienprofilen des 3-di- mensionalen Höhenprofils einzubeziehen und am Ende ist die daraus erhaltene Emissivitätsver- teilung f_emi(x,y) durch Skalarmultiplikation mit der Elektronen-Intensitätsverteilung f_e-(x,y) zu gewichten. In entsprechender Weise werden dann vorzugsweise wiederum mehrere solche Flä- chenabschnitte in Umfangsrichtung der Brennbahn untersucht. The present invention relates to an X-ray rotating anode analysis system for analyzing a used X-ray rotating anode, which has a circumferential focal path on a surface section thereof. The present invention further relates to a method for analyzing such a used rotating X-ray anode. Rotary X-ray anodes are installed in X-ray tubes, which in turn are integrated into corresponding X-ray devices. The rotating X-ray anodes are used to generate X-rays, as explained below: In use, electrons are emitted from a cathode of the X-ray tube and accelerated in the form of a focused electron beam onto the rotating X-ray anode. Due to the rotational movement of the X-ray rotating anode, a ring-shaped path – the focal path – is scanned by the electron beam. A large part of the energy of the electron beam is converted into heat in the X-ray rotating anode, while a small portion is emitted as X-rays. The locally released amount of heat leads to strong heating of the X-ray rotating anode. The rotation of the X-ray rotating anode counteracts overheating of the anode material. Particularly in the high-power range, high radiation outputs of the emitted X-rays are required, and this applies in particular to the application area of medical imaging, such as for computer tomographs. Every time the material of the focal path is moved under the electron beam due to the rotation, the surface of the focal path in the area of the focal spot first experiences a high temperature increase and thermally induced stresses, and then a temperature drop again. This causes the focal path to age, which can be seen, among other things, in a roughening of its surface, the formation of cracks, grain breakouts and/or local melting. Aging of the focal path leads to a reduction in the emitted radiation power and to a deterioration in the stability of the operation of the X-ray tube. However, other effects, such as aging of the cathode (emitter), wear in the area of the bearing components and/or distortion of the X-ray rotating anode also lead to such a reduction and/or deterioration. Assessing the causes to which this can be attributed represents a challenge. If the X-ray rotating anode is suspected or identified as a (contributory) cause, the question of its further use arises. The options available are immediate, particularly if the rotating X-ray anode continues to function Further use, provided that functionality can be restored, preparation (also referred to as “rework”; e.g. revision of the focal path, processing and re-application of the focal path, mechanical post-processing in the area of the bearing components, etc.), or otherwise recycling of the X-ray rotating anode. This decision is often made subjectively by individuals after a visual inspection of the X-ray rotating anode. From an ecological, sustainability and cost perspective, it is desirable to send rotating X-ray anodes that can be further used or reprocessed to one. The condition of the focal path is a key influencing factor with regard to the further use of the X-ray rotating anode. From the published publication CN 114428099 A an X-ray rotating anode test stand for assessing X-ray rotating anodes is known, in which an X-ray rotating anode to be examined is introduced into a vacuum chamber of the test stand, rotated and brought to operating temperature in the area of its focal path by means of an electron beam . The test stand also has a temperature sensor for detecting the temperature of the rotating X-ray anode and a control device which, among other things, evaluates a condition of the rotating X-ray anode depending on the heat supplied and the detected temperature. Furthermore, in the publication by Siller, Maximilian, et al. "Geometrical model for calculating the effect of surface morphology on total x-ray output of medical x-ray tubes." Medical Physics 48.4 (2021): 1546-1556 describes a geometric calculation model through which the effect of surface morphology on the emitted radiation power of medical X-ray tubes can be determined. As part of this publication, X-ray standing anodes were loaded using a pulsed electron beam in such a way that their surface morphology in the area of the focal spot corresponds to that of aged X-ray standing anodes and the 3-dimensional height profile of this surface was measured using laser scanning confocal microscopy (LSCM for short: Laser Scanning Confocal Microscopy). Using the geometric calculation model, a reduction in the emitted radiation power was determined due to the surface structures contained in the 3-dimensional height profile compared to a smooth surface. Furthermore, the geometric calculation model was verified with experimental comparison values. Accordingly, the object of the present invention is to provide an analysis system for used rotating X-ray anodes that have been removed from the respective X-ray tube. to provide the condition of the respective X-ray rotating anode in the area of its focal path can be assessed reliably and objectively. The object is achieved by an X-ray rotating anode analysis system according to claim 1 and by a method for analyzing a used X-ray rotating anode according to claim 14. Advantageous developments of the invention can be found in the dependent claims, which can be freely combined with one another. According to the present invention, a rotating X-ray anode analysis system for analyzing a used rotating X-ray anode having a revolving focal path on a surface portion thereof is provided. The X-ray rotating anode analysis system has a positioning device for the X-ray rotating anode, an image recording unit, and a data processing unit coupled to the image recording unit. The positioning device and the image recording unit are designed such that the X-ray rotating anode can be positioned as an individual component (ie in a state removed from the X-ray tube) at a predetermined position relative to the image recording unit. The image recording unit and the data processing unit are set up in such a way that a 3-dimensional height profile of a surface section of the X-ray rotating anode in the area of its focal path can be recorded by the image recording unit and the data processing unit, and that by the data processing unit from the recorded 3-dimensional height profile or from a Part of this is an expected radiation power or a size of the X-ray rotating anode that is characteristic of the expected radiation power. The expected radiation power, determined via the 3-dimensional height profile, is a key criterion, generally with regard to the expected performance of the X-ray rotating anode and specifically with regard to the condition of the focal path. The surface morphology of the focal path is a significant influencing factor on the emitted radiation power, since unevenness leads to local absorption effects of the emitted X-rays. The determined, expected radiation output is therefore essential for the decision on the further use of the relevant X-ray rotating anode. Furthermore, based on the 3-dimensional height profile, further advantageous evaluations are also possible, as will be explained using further training. The automated determination of the expected radiation output by the X-ray rotating anode analysis system represents a significant advantage, especially in comparison to an optical assessment of X-ray rotating anodes Individuals, as it is objective and allows for the inclusion of significantly more data and details. Compared to evaluation methods that are carried out on the X-ray rotating anode in the installed state in the X-ray tube, such as compared to the direct measurement of the emitted radiation power and / or the evaluation of backscattered electrons, the X-ray rotating anode analysis system according to the invention has the advantage that the state of the focal path is directly recorded and the result of the analysis is not distorted by other influencing factors (e.g. aging of the cathode, filters used, etc.). The X-ray rotating anode analysis system is a system that differs from an X-ray device or an X-ray tube; in particular, it does not have a vacuum piston or a unit for accelerating an electron beam onto the X-ray rotating anode. Finally, by using an appropriately configured data processing unit, the present invention advantageously uses the options of automated calculations, which enable the processing of large amounts of data. At the same time, the use of the image recording unit and the positioning device eliminates the need for expensive components, such as those used in other evaluation methods (e.g. when generating an electron beam, when detecting backscattered electrons in a spectral-dependent manner, etc.). The “used X-ray rotating anode” does not form part of the claimed X-ray rotating anode analysis system; reference is only made to the former to describe the function and design of the X-ray rotating anode analysis system. The “focal path” refers to at least the (annular) surface area of the rotating X-ray anode, which is scanned by the electron beam when the rotating X-ray anode is in use. In many cases, X-ray rotating anodes have an annular coating (on a support body formed underneath) in this surface area and in areas directly adjacent to it, which is specifically designed for the generation of X-rays. Suitable materials for the coating are, in particular, materials with a high atomic number, such as tungsten, tungsten-based alloys, in particular tungsten-rhenium alloys (e.g. with a rhenium content of up to 26% by weight, preferably in the range of 5- 15% by weight, in practice typically in the range of 5-10% by weight. In the latter case, “focal track” refers to the annular coating of the rotating X-ray anode. The design of rotating X-ray anodes means that there is an axial direction (along or parallel to the axis of rotation to which the rotating X-ray anode is located). Is essentially rotationally symmetrical; also referred to as z-direction), a circumferential direction (circulating around the axis of rotation, in the plane perpendicular to the axis of rotation) and radial directions, which each extend away from the axis of rotation in the plane perpendicular to the axis of rotation, are defined (and ultimately span the main extension plane of the X-ray rotating anode). The x and y directions also run in this plane, with the y direction corresponding to the X-ray exit direction. The surface section whose 3-dimensional height profile is recorded can extend over or cover the entire circumferential focal path. However, it can also only include one or more partial areas thereof, in particular in the radial direction the area that is actually scanned by the electron beam (in particular in the case of a radially wider focal path covering), and/or at least one in the circumferential direction Sector or other cutout (e.g. rectangular). Preferably, the at least one subarea included is then an area representative of the surface morphology of the focal path or alternatively also the most severely damaged area, which can be determined, for example, using a simple (e.g. only 2-dimensional) overview created at the beginning. Image recording of the focal path can be assessed. Since the focal path surface is typically curved and inclined to the main extension plane (typically this corresponds to the course of a truncated cone surface), corresponding corrections must be made in a known manner so that the heights of the individual image points are exact in the 3-dimensional height profile relative to the ideal course of a (theoretically assumed) smooth focal path (ie a truncated cone surface). When determining the “expected radiation output” – as is the case with the practical use of rotating X-ray anodes – the entire relevant (wavelength) spectrum of the X-rays is taken into account. Furthermore, depending on the operating conditions, filtering typical in X-ray devices, which in particular reduces the long-wave radiation component, is also preferably used. The kinetic energy released in air, KERMA (KERMA: kinetic energy released in matter; German: kinetic energy transferred to matter), is preferably used as the relevant physical quantity for the radiation output. It is measured in the physical unit gray (joule/kilogram) and indicates how much energy (in joules) is released per kilogram of matter (here air), with the entire relevant radiation spectrum (i.e. across all wavelengths). across) is summed up. However, a different physical quantity that is characteristic of the radiation power can also be determined, which is corresponding in its significance, such as, for example, a reduction in the radiation power that is to be expected due to the surface morphology of the focal path, a ratio of the expected radiation power relative to one Comparative radiation power of a smooth focal path surface, or a different definition/representation of the radiation power and/or the use of no or different filtering. The positioning device is designed to position the X-ray rotating anode as an “individual component”, ie in a state that has been removed from the X-ray tube. In particular, the positioning device can engage or rest against a central opening/bore, on a centrally mounted stem, on a circumferential section and/or on an underside of the X-ray rotating anode that is opposite the focal path in the axial direction. In addition to a system and/or an intervention, it can also be designed for fixing and, if necessary, also for rotating the X-ray rotating anode about its axis of rotation. The positioning device, the image recording unit and the data processing unit can all be integrated into one and the same overall device. Alternatively, they can also be designed as units designed separately from one another: what is then essential is that the positioning device enables exact positioning of the rotating X-ray anode to be examined relative to the image recording unit (which can also be achieved, for example, by appropriately holding the image recording unit relative to the positioning device is possible). Furthermore, the coupling of the data processing unit to the image recording unit is essential, so that at least data (image data) can be transferred from the image recording unit to the data processing unit. In particular, they are in communication and data exchange with one another. The data processing unit itself can be completely integrated into the image recording unit, but it can also be completely or partially outsourced to at least one other device. The use of the data processing unit means that it is a computer-assisted process. The acquisition of the 3-dimensional height profile and the determination of the expected radiation power are carried out in particular according to (at least) one algorithm, which can be executed by one or more appropriately set up software module(s). This means that both steps are software-supported. The 3-dimensional height profile contains for everyone Image point (pixel) along the entire area of the captured surface section contains the associated height information. In particular, it is a 3-dimensional height profile recorded and created in high resolution. In particular, work is carried out with a resolution of ≤ 5 μm in all three spatial directions, preferably with a resolution of ≤ 4 μm. The resolution can be increased by special methods, in particular by recording a larger number of individual images by the image recording unit and processing the corresponding image data obtained. Achieving a high resolution is particularly advantageous in the height direction due to the shielding effects of raised surface structures (in practice, a resolution of up to ≤ 1 μm could be achieved in all three spatial directions). The expected radiation power can be determined from the entire recorded 3-dimensional height profile or even from just part of the information. As will be explained below with regard to further developments of the present invention, a surface profile that only covers a partial area of the detected surface section, or even just one or more line profile(s), can be used as a basis. According to a further development, the image recording unit and the data processing unit are set up in such a way that using electromagnetic radiation (in particular in the wavelength range of 10-3,000 nm; nm: nanometers), several individual images, each with different depth information, can be created of a surface section of the X-ray rotating anode to be analyzed and that a 3-dimensional height profile of the surface section to be analyzed can be reconstructed from the individual images by the data processing unit. This represents an efficient procedure for creating the 3-dimensional height profile, which can be implemented cost-effectively, particularly due to the computer power available today and a low level of effort on the device side. The electromagnetic radiation used can be composed of a spectrum of several wavelengths or alternatively can also be monochrome. Furthermore, the electromagnetic radiation used can also have a long coherence length of the waves (laser), in which case it is typically monochrome radiation. Basically, there are various possibilities known in the prior art to create the majority of individual images and then the 3-dimensional height profile from them. The image recording unit preferably works according to optical methods. For example, the individual images can be from different at certain angles and then combined to form the 3-dimensional height profile (methodology of photogrammetry). Alternatively, it is possible, for example using the examination method of laser scanning confocal microscopy (LSCM for short: Laser Scanning Confocal Microscopy), to adjust the focus of the optics (for example using a corresponding aperture) step by step (preferably in steps ≤ 0.5 μm, for example in steps of 100 nm; in modern devices, significantly smaller step sizes can be set) to different heights (e.g. perpendicular to the plane of the surface section to be analyzed) and to record the sharply imaged partial areas as individual images in order to then add these individual images to the Combine 3-dimensional height profile. According to a further development, the image recording unit and the data processing unit are set up in such a way that, in particular using electromagnetic radiation in the wavelength range of 380 nm - 780 nm (this corresponds to the visible range for the human eye), several individual images of the surface section to be analyzed from different ones Angles can be created. By varying the recording directions, corresponding depth information (in the axial or z direction) can be obtained. Furthermore, the angle of illumination of the surface section is preferably also varied - either together with the recording direction or independently of the respective recording direction - and the shadow cast by the surface structures that the surface section to be analyzed has is also evaluated. In particular, you can work with “white” light, which covers a spectrum over this wavelength range. In this way, the image recording unit (camera) can work with the methods of (light) optics and record the high-resolution individual images in an efficient and cost-effective manner. In particular, the image recording unit records the individual images with a corresponding magnification (eg in the range of 5-20x, in particular 10x). The 3-dimensional height profile can then be created from the individual images taken from different angles (number ≥ 2). The principle applies that the resolution of the 3-dimensional height profile created from them can be increased with the number of individual images of the surface section to be analyzed taken from different angles. Accordingly, the number of individual images of a surface section to be analyzed taken from different angles is preferably ≥ 20, even more preferably it is in the range of 50-100. Accordingly, this principle also applies if the alternative variant in which the focus stepwise (preferably in steps ≤ 0.5 μm, for example in steps of 100 nm) is set to different heights and the sharply imaged partial areas are recorded as individual images, in which case a number of ≥ 200, in particular ≥ 500 individual images is preferred. If a step size of 100 nm is set and a height range of, for example, 100 μm is to be covered, this corresponds to, for example, 1000 individual images. According to a further development, the data processing unit is set up in such a way that the expected radiation power or the characteristic size of the X-ray rotating anode is based on an automatically calculated absorption of X-rays along an X-ray exit direction, taking into account local absorption effects due to local surface modifications or surface structures according to the recorded 3- dimensional height profile can be determined. The advantage of this development is that not only one or a few individual physical quantities that are characteristic or descriptive of the surface morphology as a whole, such as an average roughness value R _a or a square roughness R _q , are used, but that the absorption Each (local) surface modification (elevation, crack, grain breakout, local melting, etc.) located in the analyzed surface section is determined and their effect on the expected radiation output is therefore taken into account. This also enables additional analysis options, such as the detection of serious local damage (e.g. large cracks or grain breakouts) and/or circumferential fluctuations in the expected radiation output, which - even with an otherwise acceptable surface morphology Surrounding surface areas of the focal path – can lead to a different assessment of the X-ray rotating anode. This determination is carried out in particular in a computer-assisted manner (ie in particular by means of the data processing unit) using a corresponding algorithm that can be carried out by one or more correspondingly set up software module(s). The consideration of all local absorption effects (ie, for example, for each image point or pixel or for each coordinate of an included surface section or line profile) is made possible by the computing power available today. The “X-ray emission direction” mentioned is determined by the geometry of the respective X-ray rotating anode. Typically, the section of the X-ray rotating anode on which the focal path is formed corresponds to the lateral surface of a truncated cone, this lateral surface being relative to the radial direction (based on the axis of rotation) is inclined by an angle of inclination (e.g. 10°). The X-ray exit direction in the respective X-ray device usually runs exactly along the radial direction, so that it is at the angle of inclination (of eg 10°) relative to the lateral surface and thus to the surface of the focal path (locally approximated as a plane). is inclined. According to a further development, the data processing unit is set up in such a way that, for the automated calculation of the absorption of X-rays, at least one line profile which extends in the X-ray exit direction over a predetermined minimum length along the detected surface section of the X-ray rotating anode and local surface modifications or surface structures according to the 3-dimensional height profile can be used. By selectively using one or more line profiles according to this development, the required computing power can be reduced. Each line profile reflects the height profile according to the 3-dimensional height profile along the specified direction. The respective line profile should extend in the X-ray exit direction at least over the extension length of the focal spot along the detected surface section of the X-ray rotating anode in this direction. This minimum length is to be used because - as is known - the electron beam is not focused exactly on a point on the rotating X-ray anode, but rather has a finite extent (ie the focal spot) on the focal path surface with a certain electron intensity distribution (cf. Rolf Behling “Modern Diagnostic X-Ray Sources”, 2nd edition, 2021, pp.226-231). The focal spot can be assumed to be specific to the respective X-ray tube in which the rotating X-ray anode is used (if known) or a generally common focal spot size and electron intensity distribution on the focal path surface (e.g. in the range of 4-12 mm, in particular of eg 10 mm, maximum extension in at least one direction; however, if necessary, only a partial area with the highest electron intensity can be used). Furthermore, it should be explained: due to the typically provided angle of inclination of the focal path formed (on the lateral surface of a truncated cone) relative to the X-ray exit direction (which typically corresponds exactly to the radial direction), the line profile results from a (along the axial direction) projection of the X-ray exit direction onto the detected surface section, which is indicated above by the formulation “in the X-ray exit direction over a predetermined minimum length along the detected surface section”. is expressed. As will be explained below with regard to simplification/approach No. 2, the use of such line profiles and the approximation of the focal spot as a linear, correspondingly adapted intensity profile is particularly advantageous for rotating X-ray anodes due to the high-speed rotation that occurs during use . According to a further development, the data processing unit is set up in such a way that, for the automated calculation of the absorption of X-rays, it uses at least one surface profile, which extends in the X-ray exit direction over a predetermined minimum length and essentially perpendicular thereto over a predetermined minimum width along the detected surface section extends and has local surface modifications according to the 3-dimensional height profile. Including at least one surface profile has the advantage that all surface modifications on the included surface are included in the calculation. Each surface profile reflects the height profile for each pixel within the included area according to the 3-dimensional height profile. The above explanations regarding the length and course of the line profile apply accordingly to the minimum length and its course. With regard to the width, the area included can in particular be sector-shaped (ie the inside and outside each run in the circumferential direction, with the inside having a smaller extent than the outside). However, different shapes of the surface profile are also possible. Both in the further development concerning the line profile and in the one concerning the surface profile, only a single (eg representative) line or surface profile, which only picks out a line or a surface section of the focal path, can be used for the determination. In particular, several line or surface profiles, preferably evenly distributed in the circumferential direction over the circumferential focal path, are used. Furthermore, they can cover or encompass the entire surrounding focal path. According to a further development, the data processing unit is set up in such a way that at least one of the following input variables is included in the automated calculation of the absorption of X-rays: - Depth of generation (in the focal path) of X-rays, which correlates with the penetration depth of electrons into the focal path to be analyzed; - X-ray exit angle; - Material of the focal path of the X-ray rotating anode; - size of the focal spot; - Electron intensity distribution of the focal spot; and - filters. By taking these input variables into account, the accuracy and reliability of determining the expected radiation output is increased. The penetration depth of electrons into the focal path to be analyzed is basically an intensity distribution over the depth, which depends on the acceleration voltage of the electrons. Correspondingly, the correlating generation depth of X-rays is also an intensity distribution (which, among other things, does not correspond exactly to the intensity distribution of the penetration depth of electrons due to absorption effects). To simplify matters, an average value of, for example, 1.6 μm (μm: micrometers) can be assumed for the generation depth of .6 μm). The X-ray exit angle corresponds to the inclination angle explained above (which is usually 10° or 7°) and it is - based on the assumed generation depth of X-rays - when determining the path length of the generated X-rays through the material of the focal path and the associated (material-dependent) absorption of X-radiation. Depending on the material of the focal path of the X-ray rotating anode and depending on the assumed acceleration voltage of, for example, 100 kV (kV: kilo-volt), the generated X-ray spectrum can be determined (available from publicly available sources). Furthermore, the absorption of the X-rays generated until it emerges from the surface of the focal path depends on the material of the focal path (as well as on the respective wavelength of the X-ray spectrum), which is why the material of the focal path is preferably taken into account when determining the radiation power. The above explanations apply with regard to the size and electron intensity distribution of the focal spot (depending on the type of calculation, they can be specified as an intensity distribution over an area or as a linear intensity distribution with the corresponding size). Furthermore, filtering is used in X-ray devices (e.g. through borosilicate glass, which is used as a component in the radiation path, and/or aluminum or copper as specific, wavelength-dependent filters; both collectively referred to as “filters” or “ “Filtering”). Specific, wavelength-dependent filters (e.g. made of aluminum or copper) are used to reduce the proportion of long-wave radiation (also referred to as “soft” radiation), as this makes little or no contribution to imaging and leads to unnecessary radiation exposure. Accordingly, the wavelength-dependent filtering by filters typically used in X-ray devices (e.g. 2.5 mm borosilicate glass and 2 mm aluminum filtering) is preferably included in the determination of the expected radiation output. According to a further development, the data processing unit is set up in such a way that damage to the focal path of the rotating X-ray anode in the area of the surface section can be recognized and categorized from the captured 3-dimensional height profile or from otherwise captured image information of a surface section of the focal path. In addition to determining the expected radiation output, the detection and categorization of damage, e.g. according to its type, such as roughening, local melting, crack, grain breakout, and/or according to its severity, e.g. height/depth, lateral extent, etc., is important for the Assessment of the condition of the focal path is another important criterion and therefore helpful for issuing a further recommendation for the use of the rotating X-ray anode in question. According to a further development, the individual images recorded from different angles of a surface section to be analyzed form the basis for creating the image information recorded elsewhere. In particular, each pixel can be assigned a coordinate (in all three spatial directions), an RGB value (R: red component, G: green component, B: blue component of the additive color space), a SW value (S: black component, W: white component with regard to grayscale representation ), as well as additional information if necessary. Based on this, different 2-dimensional contrast representations of the analyzed surface section can be created, from which - individually as well as in combination of several such contrast representations - damage to the focal path of the X-ray rotating anode in the area of the surface section can be particularly easily recognized and categorized are. In addition, the image information recorded in other ways can also be derived from the 3-dimensional height profile (e.g. representation of the minimum and maximum heights, etc.) or formed by or derived from an image recorded separately with a special camera setting . For example, cracks that extend deep into the material of the focal path or even extend through the entire focal path coating and/or local melting that lead to clearly raised melt beads on the surface of the focal path can be an indication that the focal path needs to be reworked to a considerable extent (e.g. by removing a significant portion of the focal path or even the entire focal path covering and by reapplying the focal path material) and not just superficial sanding is sufficient. Such automated recognition and categorization is particularly software-supported. The software can in particular be designed and set up in such a way that it learns or has previously learned this recognition and categorization through machine learning (German: machine learning). As part of this machine learning, the software is trained in particular by having an expert mark and categorize (“label”) damage in corresponding example images (e.g. the 3-dimensional height profile or otherwise captured image information of a surface section of the focal path), whereby the software accessed the example images and their labeling and categorization. The software is set up in such a way that it recognizes and learns patterns from the example images using an applied learning strategy. The quality of recognition and categorization by the software increases with the number and quality of sample images provided and thus “labeled”. Furthermore, a suitable representation of the surface section in question can also facilitate recognition and categorization, which is why it can also be done on the basis of image information recorded elsewhere. According to a further development, the image recording unit and the data processing unit are set up in such a way that at least one image recording of a further surface section of the rotating X-ray anode in the area next to its focal path can be captured by the image recording unit and the data processing unit. In this way, additional conclusions can be drawn about the quality of the other areas of the X-ray rotating anode, which can be located, for example, on the same side of the focal path (top side) or - viewed in the axial direction - on the opposite side of the focal path (back). As described above, a 3-dimensional height profile or otherwise captured image information can also be generated from the at least one image recording in order to carry out further evaluations. According to a further development, the data processing unit is set up in such a way that further usage options for the X-ray rotating anode can be evaluated based on the determined, expected radiation power or based on the characteristic size for this and a corresponding usage recommendation can be made (e.g. via a display or a Display unit of the data processing unit) can be output. In this way, the recommendation for use issued is based on an objective assessment of the X-ray rotating anode, taking into account the condition of the focal path, so that in particular those X-ray rotating anodes that can be directly reused or restored through processing (also referred to as “rework”) , can also be used for such resource-saving purposes. In addition to the expected radiation output, other criteria, such as damage to the focal path or the condition of other areas of the X-ray rotating anode, can also be taken into account in the evaluation. A further recommendation for use may in particular include one or more of the following options: - direct further use of the X-ray rotating anode, - superficial grinding of the focal path surface, - local repair of the focal path in the area of severe damage (e.g. local removal and re-application of focal path material), - large-scale mechanical removal of the entire focal path material (in particular the entire focal path covering) or a corresponding surface area, subsequent application of focal path material and optionally subsequent smoothing (e.g. by grinding) of the applied focal path material , - Mechanical post-processing of the X-ray rotating anode outside the focal path area (e.g. in the area of axial fastening, to eliminate imbalances, etc.), - Recycling of the X-ray rotating anode (in case of irreparable damage). In the case of direct further use or after reprocessing, the further use recommendation can also include the recommendation of specific operating conditions (e.g. operation at certain parameters or in certain X-ray tubes or X-ray machines). According to a further development, the data processing unit is coupled to a storage unit, which can in particular be distributed on a single device/memory or alternatively over several devices/memories (in particular they are in communication connection and in data exchange with one another) and the data processing unit and the storage unit is set up for at least one of the following interactions: - Information determined individually for the respective analyzed X-ray rotating anode can be stored in the storage unit by the data processing unit and read out from the storage unit (individualization, for example through automated recognition of a serial number of the rotating X-ray anode), such as recorded 3-dimensional height profiles, line profiles, area profiles, Individual images, image information recorded elsewhere, damage, each from the area of the focal path and/or next to the focal path, the determined, expected radiation output, a further recommendation for use issued, etc.; - Type-specific information for different types of X-ray rotating anodes can be stored in the storage unit by the data processing unit and read out from the storage unit, such as drawings, structure (including used connection technologies, coatings, etc.), manufacturing data (e.g. also unique identification number, etc.). is assigned to each rotating X-ray anode during production), transport data, dimensions of rotating X-ray anodes, materials of rotating X-ray anodes (in particular the focal path, an anode disk formed underneath, etc.), etc.; - Application data recorded individually for the respective analyzed X-ray rotating anode can be stored in the storage unit by the data processing unit and read out from the storage unit, such as load cycles, duration of use, rotation speeds, applied acceleration voltages between the cathode and the rotating X-ray anode, cathode type, size and electron intensity distribution of the focal spot, etc.; and - individual history of the X-ray rotating anode analyzed in each case regarding its use in the field (ie in X-ray devices) and regarding revisions and modifications made to it (such as those made after analysis in an X-ray rotating anode analysis system over the life cycle) are in the storage unit storable and readable from the storage unit. In this way, the entire “life history” of an X-ray rotating anode can be tracked and documented using the X-ray rotating anode analysis system. The data is stored in particular together with the relevant date (“date stamp”). Based on this data basis, a specific analysis can then be carried out X-ray rotating anode can make better predictions/recommendations regarding its further use options. This is sometimes summarized under the heading of life cycle management. According to a further development, the data processing unit is set up in such a way that at least one of the following additional information is included in the evaluation of the further usage options of the rotating X-ray anode: - Homogeneity of the 3-dimensional height profile along a circumferential direction of the rotating X-ray anode; - Damage to the focal path of the X-ray rotating anode in the area of the surface section; - Image recording of a further surface section of the X-ray rotating anode in the area next to its focal path; - Geometric changes in the rotating X-ray anode (e.g. can be determined by 3-dimensional measurement of the rotating X-ray anode, in particular tactilely using a probe that, for example, scans the external dimensions of the rotating - information determined individually for the X-ray rotating anode analyzed; - Type-specific information for the X-ray rotating anode analyzed; - operational data collected individually for the rotating X-ray anode analyzed; and - individual history of the X-ray rotating anode analyzed. Including at least one of this additional information improves the quality of the evaluation of the additional usage options. For example, the need for local repairs can be derived from a strong inhomogeneity of the 3-dimensional height profile along the circumferential direction. When it comes to geometric changes, imbalances that occur, an increase in the outer diameter and/or an enlargement of a central fastening hole (in the case of X-ray rotating anodes without an integrally formed stem) are particularly critical. From this it can be derived in particular the need for mechanical post-processing or, if the extent of the work is too advanced, the measure of recycling the X-ray rotating anode. Furthermore, based on this, an estimate of the remaining service life of the relevant X-ray rotating anode can also be made. This leads to an improvement in the entire life cycle management of X-ray rotating anodes. Even more extensive measures can be taken from this collected data Improvements to be derived from rotating X-ray anodes to be produced in the future, such as design adjustments, optimization of the connection technology (e.g. by soldering, welding, etc.), and/or application of coatings. Basically, the present invention relates to the X-ray rotating anode analysis system without the X-ray rotating anode to be analyzed. According to a further development, an X-ray rotating anode (to be analyzed) is accommodated as an individual component in the positioning device. This corresponds to the operational status of the X-ray rotating anode analysis system. In particular, the positioning device is designed such that the X-ray rotating anode can be positioned exactly relative to the image recording unit. This can be done in the simplest way using a corresponding (preferably adjustable) stop. It is preferred that the positioning device enables positioning of the rotating X-ray anode in at least two spatial directions (e.g. perpendicular to the axis of rotation), in particular in all three spatial directions (in particular by appropriately provided ones), at least by means of positive locking, more preferably additionally by means of frictional locking fixing elements). Furthermore, it is preferred that the positioning device, after a first fixation, enables the rotating X-ray anode to rotate about the axis of rotation by a (preferably adjustable) angle of rotation, in order, for example, to examine different sections of the focal path. The present invention further relates to a method for analyzing a used X-ray rotating anode which has a rotating focal path on a surface section thereof. The method has the following steps: - positioning the X-ray rotating anode as an individual component using a positioning device relative to an image recording unit; - Detecting a 3-dimensional height profile of a surface section of the X-ray rotating anode in the area of its focal path by the image recording unit and by a data processing unit coupled to the image recording unit; and - Automated determination of an expected radiation power or a characteristic size of the X-ray rotating anode by the data processing unit from the recorded 3-dimensional height profile or from a part thereof. The steps of detecting the 3-dimensional height profile and automatically determining the expected radiation power are carried out in particular according to (at least) one Algorithm that can be executed by one or more appropriately configured software modules. This means that both steps are software-supported. The at least one software module is in particular stored in the data processing unit or on a separate memory in such a way that it can be loaded into the data processing unit and executed on the latter. The method according to the invention achieves essentially the same advantages as the X-ray rotating anode analysis system according to the invention. Furthermore, the developments and variants explained above are possible in a corresponding manner, with the features explained on the device side in particular also being able to be carried out or carried out as corresponding method steps by the units/components mentioned in each case. In particular, the method according to the invention is carried out with the rotating X-ray anode analysis system according to the invention, in which case one or more of the developments/variants explained above can also be implemented. Further advantages and expediencies of the invention emerge from the following description of exemplary embodiments with reference to the attached figures. DESCRIPTION OF THE FIGURES: Figure 1 shows a schematic representation of an X-ray tube in a longitudinal section; Fig.2: a perspective view of an X-ray rotating anode; Fig.3: a perspective view of another X-ray rotating anode in cross section; Fig. 4: a schematic representation of an X-ray rotating anode analysis system according to the present invention; Fig.5: an exemplary 3-dimensional height profile for a focal path surface; Fig.6: Illustration of the calculation of the path length of the generated X-rays through the focal path material for a perfectly smooth focal path surface; Fig.7: Illustration of the calculation of the path length of the generated X-rays through the focal path material for a focal path surface with surface structures; Fig.8: Three diagrams, above (first diagram) an exemplary line profile of a used focal path surface, underneath (second diagram) the resulting additional path length distribution, and again underneath (third diagram) the resulting emission distribution show. Fig.1 shows an X-ray tube 2 schematically in longitudinal section. It has a glass bulb 4 with a vacuum interior 6, in which there is a cathode 8 with a heating coil 10, which emits electrons 12 when in use (ie when current flows). A rotating X-ray anode 14 is arranged opposite the cathode 8. The X-ray rotating anode 14 has a central fastening hole to which a stem (shaft) 16 is fastened by means of a fixation 17. The stem 16 connects the X-ray rotating anode 14 to a rotor 18 of an electric motor 20. The electric motor 20 has a stator 22 outside the glass bulb. During use, the X-ray rotating anode 14 is set in rotation about an axis of rotation 24 in a known manner by the electric motor 20. The electrons 12 emitted by the cathode 8 are accelerated onto a rotating focal path 26 of the rotating X-ray anode 14. When it hits the focal path 26, its kinetic energy is converted into heat and, to a smaller extent, into X-rays 28. Through an exit window 30, which can be made of a borosilicate glass, for example, and is used to extract the X-rays from the X-ray tube, part of the X-rays 28 generated are directed in an X-ray exit direction 32, which runs perpendicular to the axis of rotation 24 , extracted. In addition, other filters, such as those made of aluminum or copper, are typically used in the X-ray beam path in order to reduce the proportion of long-wave (soft) X-rays. The extracted X-rays are then used in an X-ray device to irradiate an object, such as for imaging diagnostics in a medical X-ray device. The structure of a rotating X-ray anode 33 is explained below using FIG. 2 as an example. In its basic shape, this has an anode disk 38 which is rotationally symmetrical to an axis of rotation 36 (axial direction or also z-direction) and has a central fastening hole 39. In particular, the anode disk 38 is made from a molybdenum-based material (with ≥ 50% by weight, in particular ≥ 90% by weight of molybdenum) or from pure molybdenum. On one side of the anode disk 38, the cover side, there is a circumferential focal track 40 with a focal track coating made of a tungsten-rhenium alloy (tungsten: 95% by weight; Re: 5% by weight). The circumferential area on the focal path 40 shown in dotted lines in FIG. 2 visualizes the focal spot path 41, ie the annular surface that is scanned by the electron beam (focal spot) during the rotation of the X-ray rotating anode 33. In the area of the focal path 40, the anode disk 38 has a circumferential bevel Focal path surface 42. It is angled at an angle of inclination α (in this case: α=10°) relative to a main extension plane 44 that extends perpendicular to the axis of rotation 36 and is spanned by the radial directions and is also referred to here as the xy plane. The course of the focal path surface 42 corresponds to the lateral surface of a truncated cone. The circumferential direction extends around the axis of rotation 36 locally perpendicular to the radial directions. The X-ray exit direction 46 generally runs exactly along one of the radial directions, so that it is inclined by the angle of inclination α (of eg 10°) relative to the focal path surface 42. In the rectangular coordinate system used for the description, which is spanned by the x, y and z axes, the y axis runs along the X-ray exit direction 46 (this is only shown as an example in FIG. 2 and passes through the X-ray tube the position of the exit window is fixed), the x-axis perpendicular thereto within the main extension plane 44, and the z-axis in the axial direction (as shown schematically in FIG. 2). On the back side (ie opposite the cover side) a graphite body 43 is attached (in particular soldered) to the anode disk 38. 3 shows a further embodiment of a rotating X-ray anode 34, the same reference numbers being used for matching or corresponding components/sections as in the rotating X-ray anode 33 of FIG Otherwise, reference is made to the description of the figures in FIG. 2. A graphite body is not provided in the X-ray rotating anode 34 of FIG. 3. Furthermore, it has an integrally formed stem 48 on the back, which in the schematic representation shown is composed of a socket 50 which is monolithically formed with the anode disk 38 and a pipe component 52 connected thereto (for example by welding). The tubular component 52 can also have further mechanical connection elements at its distal end for attachment to other components (such as a rotor). An X-ray rotating anode analysis system 54 according to the invention is shown schematically in FIG. It has a positioning device 56, described in more detail below, an image recording unit 58, additional image recording units 60, 62 and a data processing unit 64. The positioning device 56 is used for recording and exact positioning of rotating X-ray anodes of different designs, in particular with or without an integrally provided stem. In the present case, an X-ray rotating anode 33 shown as an example, which essentially corresponds to that of FIG. The shaft 66 can be set in rotation via a rotation device 68, which in the present case is motorized and can be controlled via the data processing unit 64, so that the rotational position of the X-ray rotating anode 33 relative to the image recording unit 58 (and the additional image recording units 60, 62) is adjustable. Furthermore, the shaft 66 is mounted on a support component 70 via the rotation device 68. The carrier component 70 in turn is connected to a (schematically indicated) frame structure 72 of the X-ray rotating anode analysis system 54 in order to ensure exact positioning of the X-ray rotating anode 33 relative to this frame structure 72 (and thus to the image recording units 58, 60, 62). to enable. Correspondingly, the image recording units 58, 60, 62 are also connected to the frame structure 72 via supports 74 in such a way that their position and tilting (see joint 76) can be adjusted exactly relative to the frame structure 72 (and thus relative to the rotating X-ray anode 33). . The image recording unit 58 (as well as the additional image recording units 60, 62) is also in communication connection with the data processing unit 64. The image recording unit 58 can be controlled via the data processing unit 64 in order to record individual images of a surface section of the X-ray rotating anode 33 to be analyzed, in particular a surface section in the area of the focal path 40 of the X-ray rotating anode 33. The image recording unit 58 is captured by a high-resolution camera (which preferably works in the optically visible range) with a magnification in the range of 5-20x and with a lateral resolution (in the xy plane, based on that in Fig. 2 defined spatial directions and also shown in Fig. 4) of ≤ 4 μm. In particular, the camera has a lateral resolution along the xy plane of the surface section of 3.355 μm and a vertical resolution in the z direction of 3.565 μm and a magnification of 10x is set, whereby the resolution can be increased by a high number of individual images . A separate lighting unit, in particular with variably adjustable positioning, is preferably provided (eg an LED with “white” light, ie which preferably covers a spectrum over essentially the visible wavelength range). Additionally or alternatively, the camera has a internally designed lighting unit (e.g. an LED with “white” light; ie which preferably covers a spectrum over essentially the visible wavelength range). The same preferably applies to the further image recording units 60, 62, whereby these can, for example, be designed and positioned so that an image recording unit 60 can record an image of a larger section of the cover side (or the entire cover side) of the X-ray rotating anode 33 and / or that an image recording unit 62 can also record an image of a larger section of the back (or the entire back) of the X-ray rotating anode 33. The control of and communication with the image recording unit 58 and with other system components of the X-ray rotating anode analysis system 54, in particular with the additional image recording units 60, 62, the rotation device 68, the tactile measuring device 84 explained below, etc., is carried out by the data processing unit 64 via interfaces 78 (schematically indicated in FIG. 4). Furthermore, the data processing unit 64 has an input and display unit 80, via which a user can make inputs (entering information, triggering actions, etc.) and corresponding ones Information (results, recommendations, input prompts, etc.) can be displayed, as well as a storage unit 82 in which data can be stored via the data processing unit and can in turn be read out from it. The recording of the individual images is preferably carried out in such a way that the rotation device 68 further rotates the X-ray rotating anode 33 by predetermined feed angles (e.g. by an angle in the range of 1-2 °) around the axis of rotation 36 in order to achieve different angular positions in each case to create individual images of a surface section of the focal path 40 to be analyzed by the image recording unit 58 (ie individual images of the surface sections, which are each located under the recording area of the image recording unit 58, so that the individual surface sections each overlap several times). In parallel, individual images (at any or alternatively only at selected angular positions) can also be created using the additional image recording units 60, 62. Furthermore, a tactile measuring device 84 is shown in FIG. Through the tactile measuring device 84, the rotating X-ray anode 33 can be measured tactilely (possibly also during its rotation) in order to determine any geometric changes in the rotating X-ray anode 33 that may have occurred. Below, with reference to FIGS. 5 to 8, an embodiment for calculating the absorption of X-rays along an X-ray exit direction, taking into account local absorption effects due to local surface modifications according to a recorded 3-dimensional height profile, will be described in order to use this as an example then to determine a quantity that is characteristic of the expected radiation output. Additional information and literature on the simplifications made and the approach to this calculation can be found at Siller, Maximilian, et al. "Geometrical model for calculating the effect of surface morphology on total x-ray output of medical x-ray tubes." Medical Physics 48.4 (2021): 1546-1556. In order to be able to carry out this calculation automatically, software is in particular provided, through which the calculation can be carried out according to a corresponding algorithm, and can be loaded into the data processing unit (for example into the data processing unit 64 shown in FIG. 4) and can be executed thereon. 5 shows an example of a 3-dimensional height profile M _height (x,y) of an analyzed surface section, as is typical, for example, for aged focal paths of rotating X-ray anodes after their use in X-ray devices (we refer to that in Fig .2 and 4 defined coordinate system referred to). Each image point or pixel in the xy plane of this 3-dimensional height profile is assigned a corresponding height value or z-value, which is represented by the grayscale representation. The z range shown ranges from -30 μm (shown in black) to 0 μm (shown in gray) to +30 μm in the positive area (shown in white) in the negative area (μm: micrometer). Furthermore, typical damage to the focal track surface that occurs after prolonged use is shown in FIG. In the lower left part of the profile two crater-shaped depressions labeled “A” can be seen. These are grain breakouts of the focal path material. In the right half you can see a narrow depression that extends essentially vertically across the central part of the image and is labeled “B”. This is a crack in the focal track material. Furthermore, a pearl-like elevation can be seen in the upper right part, which is labeled “C” and which is a local melting. Such a 3-dimensional height profile – independent from its specific design and the specific height profile - forms the starting point for calculating the absorption of X-rays along the X-ray emission direction. The calculation according to the present embodiment is based on the concept that for each X-ray generation point (corresponding to the generation depth of X-rays in the z direction below the focal path surface) the absorption of the generated is determined from the 3-dimensional height profile and then - as long as the X-rays are directed along the X-ray exit direction - is summed up or integrated over all relevant generation points (in this case: a line profile). The X-ray radiation emitted at each generation point in the X-ray exit direction (“output spectrum”) is based on the X-ray spectrum (braking radiation distribution with characteristic lines) that is characteristic of the respective focal path material depending on the acceleration voltage (in this case 100 kV). . Data and calculation methods for typical acceleration voltages and focal path materials are available in the literature (to simplify matters, pure tungsten can be used for tungsten-rhenium alloys with a predominant proportion of tungsten due to the similar atomic number and density). Furthermore, it must be taken into account that only those individual image points or pixels of the 3-dimensional height profile (or in this case: a line profile derived from it) are to be included that lie within the focal spot area of the rotating X-ray anode, and these then correspond to the electrons -Intensity distribution must be weighted, although in the present calculation model this only takes place as one of the last steps. In the present case, the calculation is carried out as an example for a line profile of a surface section of the focal path to be analyzed, assuming that electrons are accelerated with an acceleration voltage of 100 kV onto this section with a typical size and intensity distribution of the focal spot. According to the present embodiment, the following simplifications/approaches are made: 1. For simplicity, an average generation depth d _e of X-radiation is used, and not an actually occurring distribution of the generation depths along the z-axis (the latter would be for each xy coordinate multiple creation points along the z coordinate according to the distribution function and require summing or integration over these generation points). Ie, according to this simplification, for each image point or pixel with an associated xy coordinate in the z direction, exactly one generation point with a z coordinate d _e- below the focal path surface is assumed. Average production depths depending on the surface tension applied between the cathode and the X-ray rotating anode in, for example, tungsten-based focal path material can be found in the literature. For example, for an acceleration voltage of 100 kV, an average generation depth _of X-rays in tungsten-based material is 1.6 μm in Poludniowski, Gavin G., and Philip M. Evans. "Calculation of x-ray spectra emerging from an x-ray tube. Part I. Electron penetration characteristics in x-ray targets." Medical physics 34.6 Part1 (2007): 2164- 2174 (other relevant source: Behling, Rolf. “Modern diagnostic x-ray sources: technology, manufacturing, reliability”. CRC Press, 2021, p.71). 2. Regarding the size and electron intensity distribution of the focal spot: In comparison to a static arrangement of a focal spot on a focal path surface (see, for example, standing anodes), in which an electron intensity distribution over the affected area (x,y coordinates) of the focal spot, a linear (along the X-ray exit direction or y-direction) and correspondingly adapted intensity profile can be used as a basis for an X-ray rotating anode due to the rotation in use. For example, this can be determined using rotating X-ray anodes and in many cases (depending on the cathode type) can be easily approximated by two overlapping sine functions (in many cases the intensity distribution is represented by a survey that has two overlapping “humps” in the y-direction , educated). Alternatively, it can also be simulated taking into account the electromagnetic interactions, also for different cathode types as required. Regarding the 3-dimensional height profile: Accordingly, a comparison of the radiant power emitted by an aged focal path surface with surface structures with the radiant power emitted by a perfectly smooth focal path surface does not require a two-dimensional observation of the recorded 3-dimensional height profile and a appropriate application of area functions (with x- and y- Coordinates) must be carried out (see, for example, the approach taken in the above-mentioned publication by Maximilian Siller et. al with regard to standing anodes), but it is sufficient if corresponding line profiles of the 3-dimensional running in the radial direction Height profile is used and compared with each other (which point in the X-ray exit direction or y-direction once per revolution during the rotation of the X-ray rotating anode). This is described in the calculation below using a line profile running in the radial direction along the surface of the focal path, which can be obtained as under No. 3 below. For the calculation below, it is assumed that the radial direction is simultaneously aligned in the X-ray exit direction or y-direction. 3. Regarding the line profiles to be created in the radial directions: Due to the rotational symmetry of the rotating X-ray anode, the image points/pixels of the recorded 3-dimensional height profile typically do not lie exactly along the respective radial direction, so that to generate the in this direction running line profiles, a corresponding approximation to the captured surface structure must be made (e.g. through a fitted height profile that runs along the captured image points/pixels) in order to obtain corresponding z-coordinates for all y-coordinates (or radial coordinates) along the line profile. values (i.e. heights). This determination of the line profiles running in the radial direction is preferably carried out with software support, for example by means of a fitting function. 4. To simplify matters, only the radiation power of each generation point of the line profile used as an example is determined strictly in the direction of the radial direction, which in the present case is assumed to be aligned in the X-ray exit direction or y-direction, and not for everyone Generation point first a cone-shaped radiation emitted in the area around the X-ray exit direction, in order then to sum up or integrate the radiation emerging exactly in the X-ray exit direction across the generation points. This enables calculation based on line profiles, as will be explained in detail below. 5. Furthermore, regardless of the generation point and the surface structures present locally at the generation point along the X-ray exit direction, it is assumed that the emitted X-rays have a minimum path length in the focal path material. This minimum path length is to be selected depending on the angle of inclination (in the present case: α=10°) as a fraction of the path length of the locally emitted radiation through the focal path material that is expected on a smooth surface, e.g. 5 μm with an expected path length of 9.07 μm (for example with an inclination angle of the focal path of

=10°). Due to special features of the 3-dimensional height profile and its resolution, theoretically possible peaks in the radiation power emitted locally by individual generation points, which would lead to local distortions, are avoided (for example on locally very steeply sloping flanks of the upper in the X-ray emission direction - surface structure of the focal track surface). Below, with reference to Figures 6, 7 and 8, it will be explained how the absorption by the focal path material is determined for each generation point of X-rays, taking into account the local surface modifications according to the 3-dimensional height profile: In Fig .8 in the top diagram is an exemplary line profile of a used focal path surface, plotted as height (unit: millimeters) (see “height [mm]” in the diagram) over the y-direction (unit: millimeters) ( see “y[mm]” in the diagram). It can be generated, for example, from a section of the 3-dimensional height profile shown in FIG. 5 along the X-ray exit direction y. Figures 6 and 7 each show schematically a section of such line profiles of focal path surfaces. 6 first shows the situation of a perfectly smooth focal path surface 92, which is inclined with an angle of inclination α=10° (shown larger in FIGS. 6 and 7 for illustration) relative to the y-direction. Using two exemplary electrons 94, 96, which impinge on the focal path surface 92 with two different y coordinates and (shown in simplified form) penetrate to the respective generation point 98 according to the average generation depth _of x-rays, the of The path length d x-ray traveled by the generated x _-radiation in the x-radiation exit direction (y-direction) is shown through the focal path material. Regardless of the location where the electrons appear within the focal spot, the path length traveled can be determined using the following formula:

At d _e- =1.6 μm and α=10°, this results in a constant “theoretical path length” d _x-ray =9.07 μm. That is, with a perfectly smooth focal path surface 92, the generated X-rays are first subjected to filtering through the focal path material over a path length d _x-ray of constant 9.07 μm before emerging from the focal path surface. It is then filtered by filter 102 before it hits a detector 104 (if there are no further obstacles or objects to be irradiated in the radiation path). For example, a filter made of borosilicate glass with a thickness of 2.5 mm (eg as an exit window) and an aluminum filter with a thickness of 2 mm can be used in the calculation model. With regard to the filtering through the focal path material, filtering through pure tungsten (W) can be used for tungsten-rhenium focal paths (with a predominant proportion of tungsten), since tungsten (W) and rhenium (Re) differ only slightly in their atomic number and density. The absorption that occurs with a perfectly smooth focal path surface by the focal path material (over a path length of 9.07 μm each) and the filtering by the filters 102 is referred to as basic filtering. The potential base radiation power of a line profile or a y-coordinate that is to be expected with such a perfectly smooth focal path surface is used as a comparison value. In particular, based on the initial spectrum described above, the absorption by the focal path material over the path length of 9.07 μm as well as the filtering by the filter 102 initially represents the potential base radiation power in X-rays to be expected for a single y-coordinate -Exit direction determined. This is done in particular with software support (e.g. with SpekCalc pro 1.1, based on the theoretical approach of Gavin Poludniowski and Phil Evans at “The Institute of Cancer Research”, London, UK, and based on the graphical user interface by Francois deBlois , Guillaume Landry and Frank Verhaegen at McGill University, Montreal, Canada; currently available at www.spekcalc.weebly.com). The software is preferably set up in such a way that it first determines the reduction/filtering of the output spectrum for a single y-coordinate of the line profile (wavelength-dependent) (since the strength of the reduction/filtering depends on the wavelength or energy of the photons). in order to obtain a “potential base spectrum” (“potential”, since the electron intensity distribution and size of the focal spot are not yet taken into account), the intensity distribution of which is reduced compared to the initial spectrum (wavelength-dependent). Afterward A “potential base radiation power” is preferably determined for a single y-coordinate, which results from the sum or integration of the radiation powers over the different wavelengths of the potential base spectrum obtained after base filtering. Since in this case a perfectly smooth focal path surface is assumed and only the “potential” base spectrum and the “potential” base radiation power are considered (ie the electron intensity distribution and size of the focal spot have not yet been taken into account). these are constant over the different y coordinates of a line profile and accordingly also in the circumferential direction for different line profiles. In contrast, the focal track surface of FIG reference numerals). According to the calculation model, for each generation point 98 of X-rays, ie for each y-coordinate along the y-direction (X-ray exit direction) of the line profile, taking into account the surface modifications according to the 3-dimensional height profile, the path length d actually covered by the focal path material is now determined ' _x-ray (in the y direction) is determined, as illustrated in Figure 7. In order to determine this “actual path length” d' _x-ray , partial path lengths may also have to be added if the a local elevation) enters the focal path material (once or several times) before finally reaching the free area outside the focal path material. This determination and also the further calculation steps (unless otherwise stated) are preferably software-supported using appropriately set up software (e.g. Matlab R2017b 64bit; currently available at www.mathworks.com). For this purpose, the respective line profile (as shown in the top diagram in Fig. 8) is preferably imported into the software. Alternatively, one or more 3-dimensional height profiles are imported into the software and then the line profiles running in the radial direction are generated according to simplification/approach #3 above. Furthermore, the angle of inclination (here: α = 10 °) and the average generation depth of X-radiation (here: d _{e -} = 1.6 μm) must be taken into account in order to then, as illustrated in Fig. 7, for each y-coordinate of the respective line profile which is determined by the associated (around d _e- in z- To determine the actual path length d' _x-ray that originates from the generation point and is offset in the y direction through the focal path material. This can be done using the software, for example by comparing the original line profile (relevant for the focal path surface) and an otherwise identical line profile (relevant for the creation point) that is offset downwards in _the z direction into the focal path material. in order to then determine the path lengths actually traveled in the y direction depending on the respective y coordinate of the respective line profile. An additional path length distribution f _add (y) is then determined by subtracting the theoretical path length d _x-ray from the actual path length d' _x-ray (y) as follows:

To the extent that the actual path length d' _x-ray (y) deviates from the theoretical path length d _x-ray for a y coordinate, this results in an actual filtering that deviates from the basic filtering explained above. Surface modifications that occur result in an increased actual path length d' _x-ray (y) for most y coordinates compared to the theoretical path length d _x-ray (ie values > 0 for f _add ). However, for a certain proportion of the y coordinates, the actual path length d' _x-ray (y) is reduced (ie values < 0 for f _add ), in which case at least the minimum path length of 5 μm according to the above simplification/approach no. 5 is to be used (see line 2 of equation (2)). In Fig. 8, the second diagram shows the additional path length distribution, plotted as additional path length fadd(y) (unit: micrometer or μm) (“f _add (y) [μm]” in the diagram) over the y-direction (unit: millimeters) (see “y[mm]” in the diagram), which results specifically for the line profile shown in Fig. 8 above. Then, largely in the same way as for the perfectly smooth focal path (preferably supported by software, e.g. with SpekCalc pro 1.1; see above), the (wavelength-dependent) reduction/filtering of the output spectrum is generally carried out as a function of f _add (and not yet specifically for different y-coordinates) is determined in order to obtain a “potential actual spectrum” as a function depending on f _add , the intensity distribution of which is reduced compared to the initial spectrum. Afterward A “potential actual radiation power”, which results from the sum or integration of the radiation powers over the different wavelengths of the potential actual spectrum, is determined as a function depending on f _add . As a further step (preferably again supported by software, e.g. with SpekCalc pro 1.1; see above) the ratio f _red of this potential actual radiation power relative to the potential base radiation power (determined as stated above) as a function depending on f _add formed. This determined ratio f _red (f _add ) therefore indicates how much the potential actual radiation power of a point of origin of X-rays changes relative to the potential base radiation power of a perfectly smooth focal path surface depending on the additional path length f _add , which the X-rays have to travel from the point of origin changes. This determined ratio f _red (f _add ) can in particular be fitted with a function, preferably with a double exponential function (ie using a sum of two exponential functions). Starting from the minimum value (here -4.07 μm), it is greater than 1 for negative values of the additional path length f _add , then falls continuously and reaches exactly the value 1 for f _add =0. For positive values of the additional Path length f _add is less than 1 and approaches zero for increasingly larger values of the additional path length f _add . This function is now, preferably again supported by software (e.g. with Matlab R2017b 64bit; see above), specifically based on the additional path length distribution f _add (y), as it was determined for the line profile using equation (2), applied to obtain an emission distribution f _emi (y) over the various y-coordinates of the line profile, as given in equation (3) below:

The emission distribution f _emi (y) indicates the ratio of the potential actual radiation power relative to the potential base radiation power for the different y coordinates of the line profile, whereby this ratio for y coordinates with the associated negative value of f _add (ie d' _x-ray (y) < d _x-ray ) is greater than 1 and for positive values of f _add (i.e. d' _x-ray (y) > d _x-ray ) is less than 1. This means that the larger the actual path length d' _x-ray is in relation to the theoretical path length d _x-ray for the respective generation point, the lower the ratio of the potential actual radiation power relative to the potential base radiation power (ie the more emitted radiation is absorbed), and vice versa. In Figure 8, the third diagram shows this ratio or emission distribution, plotted as emission distribution f _emi (y) (“f _emi (y) [-]” in the diagram) over the y-direction (unit: millimeters) (see “y[mm]” in the diagram), which is concrete for the additional path length f _add (y) shown in the second diagram in FIG. 8, shown. Finally, in order not only to compare quantities described as “potential”, the electron intensity distribution in the y-direction (ie along the radial direction) must now be taken into account, since the radiation power generated at the respective y-coordinate depends on whether and with what intensity electrons hit this y-coordinate. For example, for this reason, damage to the focal path surface in the radial direction outside the focal spot area is less critical, since no X-rays are generated at these positions, while damage in the area of high electron intensity can be particularly critical, especially if it leads to strong shadowing . As explained under simplification/approach No. 2 above, the electron intensity distribution in X-ray rotating anodes can be described by a linear intensity profile f _e (y) (running in the y direction or radial direction). The emission distribution f _emi (y) must be weighted accordingly by this intensity profile f _e- (y) in order to obtain the ratio O(y) of the “actual radiation power” relative to the “basic radiation power” for the respective y-coordinate obtained, as shown in the equation below:

In order to then determine the ratio O _line of the actual radiation power that is emitted over the entire line profile of a damaged focal path surface with surface structures, relative to the associated basic radiation power that is emitted over the entire line profile in the case of a perfectly smooth focal path surface would be emitted, integrate O(y) over the y coordinate as represented by the equation below:

In this way, the effects of surface structures that occur in the area of a specifically examined line profile of a damaged focal path surface on the emitted radiation power can be assessed. In particular, O _line represents a characteristic value about the attenuation of the radiation power due to damage to the surface of the focal path. Furthermore, a large number of (each radially extending) can of course be used in a corresponding manner and preferably distributed in the circumferential direction around the rotating X-ray anode) line profiles can be evaluated. On the one hand, variations that can occur in the circumferential direction of the rotating X-ray anode can be determined. Furthermore, a total radiation output can also be determined by summation/integration of the O _line values obtained for the individual line profiles. The present invention is not limited to the described embodiments. For example, as an alternative to the simplification/approach No. 2 (see above) regarding the focal spot and the line profile, an electron intensity distribution over the affected area, ie a function f _e- (x,y) can also be used . Then, depending on the size of the focal spot, a plurality of adjacent line profiles of the 3-dimensional height profile must be included and in the end the resulting emissivity distribution f _emi (x,y) is obtained by scalar multiplication with the electron intensity distribution f _e- (x ,y) to be weighted. In a corresponding manner, several such surface sections are then preferably examined in the circumferential direction of the focal path.

Claims

CLAIMS 1. X-ray rotating anode analysis system for analyzing a used X-ray rotating anode (14; 33; 34), which has a rotating focal path (26; 40) on a surface section of the same, comprising: - a positioning device (56) for the X-ray rotating anode (14; 33; 34), - an image recording unit (58), and - a data processing unit (64) coupled to the image recording unit (58), the positioning device (56) and the image recording unit (58) being designed such that the X-ray rotating anode (14; 33 ; 34) can be positioned as an individual component at a predetermined position relative to the image recording unit (58), the image recording unit (58) and the data processing unit (64) being set up in such a way that the image recording unit (58) and the data processing unit (64) a 3-dimensional height profile of a surface section of the rotating X-ray anode (14; 33; 34) in the area of its focal path (26; 40) can be detected, and that by the data processing unit (64) from the detected 3-dimensional height profile or from a part of which an expected radiation output or a characteristic size of the X-ray rotating anode (14; 33; 34) can be determined. 2. X-ray rotating anode analysis system according to claim 1, characterized in that the image recording unit (58) and the data processing unit (64) are set up in such a way that, using electromagnetic radiation, several individual images, each with different depth information, of a surface section of the X-ray rotating anode (14 ; 33; 34) can be created and that a 3-dimensional height profile of the surface section to be analyzed can be reconstructed from the individual images by the data processing unit (64). 3. X-ray rotating anode analysis system according to claim 2, characterized in that the image recording unit (58) and the data processing unit (64) are set up in such a way that, using electromagnetic radiation in the wavelength range of 380 nm - 780 nm, several individual images of the surface section to be analyzed from different Angles can be created. 4. X-ray rotating anode analysis system according to at least one of the preceding claims, characterized in that the data processing unit (64) is set up in such a way that the expected radiation power or the characteristic size of the X-ray rotating anode (14; 33; 34) is based on an automatically calculated absorption of X-rays along an X-ray exit direction (32; 46) taking into account local absorption effects due to local surface modifications (100) can be determined according to the recorded 3-dimensional height profile. 5. X-ray rotating anode analysis system according to claim 4, characterized in that the data processing unit (64) is set up in such a way that it uses at least one line profile, which extends in the X-ray exit direction (32; 46), for the automated calculation of the absorption of X-rays a predetermined minimum length extends along the detected surface section of the rotating X-ray anode (14; 33; 34) and has local surface modifications according to the 3-dimensional height profile. 6. X-ray rotating anode analysis system according to claim 4, characterized in that the data processing unit (64) is set up in such a way that it uses at least one surface profile, which is in the X-ray exit direction (32; 46), for the automated calculation of the absorption of X-rays a predetermined minimum length and extends essentially perpendicularly thereto over a predetermined minimum width along the detected surface section and has local surface modifications according to the 3-dimensional height profile. 7. X-ray rotating anode analysis system according to at least one of claims 4-6, characterized in that the data processing unit (64) is set up in such a way that at least one of the following input variables is included in the automated calculation of the absorption of X-rays: - - Generation depth of X-rays; - X-ray exit angle (α); - Material of the focal path (26; 40) of the X-ray rotating anode (14; 33; 34); - size of the focal spot; - Electron intensity distribution of the focal spot; and - filter (102). 8. X-ray rotating anode analysis system according to at least one of the preceding claims, characterized in that the data processing unit (64) is set up in such a way that it uses the recorded 3-dimensional height profile or from image information recorded elsewhere of a surface section of the focal path (26; 40) Damage (A, B, C) to the focal path (26; 40) of the rotating X-ray anode (14; 33; 34) can be recognized and categorized in the area of the surface section. 9. X-ray rotating anode analysis system according to at least one of the preceding claims, characterized in that the image recording unit (58, 60, 62) and the data processing unit (64) are set up in such a way that the image recording unit (58, 60, 62) and the data processing unit (64) can capture at least one image of a further surface section of the rotating X-ray anode (14; 33; 34) in the area next to its focal path (26; 40). 10. X-ray rotating anode analysis system according to at least one of the preceding claims, characterized in that the data processing unit (64) is set up in such a way that based on the determined, expected radiation power or based on the characteristic size for this, further Options for using the rotating X-ray anode (14; 33; 34) can be evaluated and a corresponding recommendation for use can be issued. 11. X-ray rotating anode analysis system according to at least one of the preceding claims, characterized in that the data processing unit (64) is coupled to a storage unit (82), and that the data processing unit (64) and the storage unit (82) for at least one of the following interactions are set up: - information determined individually for the X-ray rotary anode (14; 33; 34) being analyzed can be stored in the storage unit (82) by the data processing unit (64) and read out from the storage unit (82); - Type-specific information for different types of X-ray rotating anodes (14; 33; 34) can be stored in the storage unit (82) by the data processing unit (64) and read out from the storage unit (82); - application data recorded individually for the X-ray rotary anode (14; 33; 34) being analyzed can be stored in the storage unit (82) by the data processing unit (64) and read out from the storage unit (82); and - individual history of the respectively analyzed X-ray rotating anode (14; 33; 34) regarding its use in the field and regarding revisions and modifications made to it can be stored in the storage unit (82) and read out from the storage unit (82). 12. Rotary X-ray anode analysis system according to claim 10 or 11, characterized in that the data processing unit (64) is set up in such a way that at least one of the following additional information is included in the evaluation of the further usage options of the rotary X-ray anode (14; 33; 34). include: - Homogeneity of the 3-dimensional height profile along a circumferential direction of the rotating X-ray anode (14; 33; 34); - Damage (A, B, C) to the focal path (26; 40) of the rotating X-ray anode (14; 33; 34) in the area of the surface section; - Image recording of a further surface section of the X-ray rotating anode (14; 33; 34) in the area next to its focal path (26; 40); - Geometric changes to the X-ray rotating anode (14; 33; 34); - information determined individually for the rotating X-ray anode (14; 33; 34) being analyzed; - Type-specific information for the X-ray rotating anode analyzed (14; 33; 34); - operational data recorded individually for the rotating X-ray anode (14; 33; 34) analyzed; and - individual history of the X-ray rotating anode analyzed (14; 33; 34). 13. X-ray rotary anode analysis system according to at least one of the preceding claims, characterized in that an X-ray rotary anode (14; 33; 34) is accommodated as an individual component in the positioning device (56). 14. Method for analyzing a used rotating X-ray anode (14; 33; 34), which has a circumferential focal path (26; 40) on a surface section thereof, comprising the following steps: - Positioning the rotating X-ray anode (14; 33; 34) as an individual component using a positioning device (56) relative to an image recording unit (58); - Detecting a 3-dimensional height profile of a surface section of the rotating X-ray anode (14; 33; 34) in the area of its focal path (26; 40) by the image recording unit (58) and by a data processing unit coupled to the image recording unit (58) ( 64); and - automated determination of an expected radiation output or a characteristic size of the rotating X-ray anode (14; 33; 34) by the data processing unit (64) from the recorded 3-dimensional height profile or from a part thereof. 15. The method according to claim 14, characterized in that this is carried out with an X-ray rotating anode analysis system (54) according to one of claims 1 to 13.