CN106658930B - adjustable X-ray source - Google Patents

Abstract

The invention discloses an adjustable X-ray source, which includes a protective box and an X-ray tube arranged in the protective box. A rotatable tray and a movable diaphragm are arranged in the protective box. The box is provided with a collimating part, the X-ray tube has an exit window, and at least two fluorescent sheets are arranged on the tray, and the X-rays emitted from the exit window pass through the fluorescent sheet, the diaphragm and the collimating part in sequence Out of the protective box, the fluorescent sheets are all simple metal materials, and the energy point of the fluorescent X-rays emitted from one of the fluorescent sheets is greater or smaller than that of the fluorescent X-rays emitted from any other fluorescent sheet. The adjustable X-ray source provided by the present invention has a novel structure, is easy to implement, and can emit single-energy fluorescent X-rays with adjustable energy points, which are approximately point-emitted, with uniform spatial distribution, and the divergence angle and intensity of fluorescent X-rays are all acceptable. Tune.

Description

Tunable X-ray source

technical field

The invention belongs to the technical field of X-ray exciting devices, and in particular relates to an adjustable X-ray source.

Background technique

In industrial and medical applications, X-ray sources are usually used for non-destructive testing, structural analysis, medical diagnosis and treatment, etc. In scientific applications, X-ray sources are often used for diffraction analysis, energy spectrum calibration, and equipment testing etc. Therefore, the X-ray source can be used in a wide range of applications. An X-ray tube is a common X-ray generator, generally composed of a metal anode and a filament cathode, both of which are sealed in a high-vacuum glass or ceramic shell. Under the condition of negative high voltage, the electrons generated by the cathode accelerate and bombard the surface of the anode, and X-rays are generated in physical processes such as energy point transition and bremsstrahlung. The energy spectrum distribution of X-rays emitted by the X-ray tube is determined by the high-voltage upper limit of the cathode, while the emission intensity is determined by the current value of the ray tube, that is, the number of bombarded electrons.

Due to the existence of bremsstrahlung, the X-ray spectrum emitted by the X-ray tube is the bremsstrahlung spectrum with continuous distribution of energy points superimposed with the characteristic radiation peak of the anode material. However, monoenergetic X-rays are required as a ray source in some fields, and the bremsstrahlung of the X-ray tube will have adverse effects on the measurement in these applications. In order to eliminate the influence of bremsstrahlung, metal filters are usually used to filter light or fluorescent X-rays. Under high voltage and high current (high power) conditions, in order to avoid melting the surface of the metal anode due to excessive local power, generally the filament The focal point of cathode focusing is very controlled, often a square focal spot of a few millimeters or tens of millimeters or a larger strip focal spot, so the emitted X-rays often have uneven spatial distribution. However, the traditional X-ray source is only designed with a fluorescent sheet of a single material, that is, it can only excite the characteristic radiation X-rays of one material, and the intensity and divergence angle of the emitted fluorescent X-rays are not adjustable. Therefore, the use of traditional X-ray sources is more limited and cannot meet the needs of development.

Contents of the invention

In order to solve the above technical problems, the present invention provides an adjustable X-ray source, which can emit quasi-monoenergetic fluorescent X-rays with adjustable energy points, and emit approximately in the form of points, with uniform spatial distribution, and the divergence angle and intensity of fluorescent X-rays All adjustable.

To achieve the above object, the technical scheme of the present invention is as follows:

An adjustable X-ray source includes a protective box and an X-ray tube arranged in the protective box. The box is provided with a collimating part, the X-ray tube has an exit window, and at least two fluorescent sheets are arranged on the tray, and the X-rays emitted from the exit window pass through the fluorescent sheet, the diaphragm and the collimating part in sequence Out of the protective box, the fluorescent sheets are all simple metal materials, and the energy point of the fluorescent X-rays emitted from one of the fluorescent sheets is greater or smaller than that of the fluorescent X-rays emitted from any other fluorescent sheet.

With the above structure, the structure is novel, easy to adjust, and high in reliability; through the rotatable tray and the fluorescent sheets of different elemental metal materials arranged on the tray, the fluorescent X-rays that can be emitted by the present invention have mono-energy characteristic radiation, and It can change the fluorescent sheet to emit fluorescent X-rays with different energy points; then the fluorescent X-rays pass through the aperture of the diaphragm and then shoot to the collimation component, so that the fluorescent X-rays form an approximate point emission effect, so that the emitted single-energy fluorescent X-rays The spatial distribution of rays is more uniform; and by adjusting the position of the diaphragm, the divergence angle of the fluorescent X-rays emitted from the protective box can be changed, and the intensity of the emitted fluorescent X-rays can be adjusted at the same time.

As a preference: the opening direction of the exit window is downward, the tray is located directly below the exit window, and the aperture is located between the tray and the collimation component. With the above structure, the included angle between the fluorescent sheet and the X-ray tube is 45°, and the fluorescent X-ray shoots to the diaphragm along the horizontal direction, and then collimates through the collimation component and then exits the protective box. The position design is reasonable, Stable and reliable.

Preferably, the tray is prism-shaped, and each of the fluorescent sheets is located on one side of the tray. With the above structure, the X-rays emitted by the X-ray tube can only pass through one of the fluorescent sheets to the diaphragm, which ensures the characteristic radiation of single energy. At the same time, by rotating the tray, the irradiated fluorescent sheets can be easily changed, and then controlled The energy point of the emitted fluorescent X-rays.

As a preference: a pallet frame for supporting the pallet is provided in the protective box, and a motor for driving the pallet to rotate is provided on the pallet frame. With the above structure, the tray can be reliably fixed and the rotation of the tray can be controlled.

As a preference: an electric translation stage for making the aperture close to or away from the tray is provided in the protective box. With the above structure, the diaphragm is installed on the electric translation stage, and by driving the lead plate to move, changing the distance between the diaphragm and the fluorescent sheet, the divergence angle of the fluorescent X-rays emitted from the protective box can be changed, and at the same time it can control The intensity of the emitted fluorescent X-rays.

As a preference: a ray tube support column for supporting the X-ray tube is arranged in the protective box. With the above configuration, the position of the X-ray tube can be reliably fixed.

Preferably, the collimation component is a lead flange, and the center of the collimation component has a collimation hole. With the above structure, the flange plate is made of lead material, so that the fluorescent X-rays can only pass through the collimation hole.

As a preference: the protective box adopts a double-layer structure of iron plates and lead plates, wherein the inner layer uses lead plates and the outer layer uses iron plates. With the above structure, the inner layer uses lead plates to shield X-rays, and the outer layer uses iron plates to make the protective box durable and protect internal parts.

Preferably, the protective box has a cable hole, and the pipeline of the X-ray tube passes through the cable hole. With the above structure, the high-voltage cables and cooling water pipes attached to the X-ray tube can be led out from the cable holes.

As a preference: the aperture is made of lead material and has a light hole. With the above structure, the aperture is made of lead material, which ensures that the fluorescent X-rays can only pass through the aperture of the aperture.

Compared with prior art, the beneficial effect of the present invention is:

The adjustable X-ray source provided by the present invention has a novel structure, is easy to implement, and can emit single-energy fluorescent X-rays with adjustable energy points, which are approximately emitted at points, with uniform spatial distribution, and the divergence angle and intensity of fluorescent X-rays can be adjusted. Tune.

Description of drawings

Fig. 1 is the three-dimensional structure schematic diagram of the present invention;

Fig. 2 is the plane structure schematic diagram of the present invention;

Fig. 3 is a right side view of Fig. 2 .

Detailed ways

The present invention will be further described below in conjunction with embodiment and accompanying drawing.

As shown in Fig. 1 and Fig. 2, a kind of adjustable X-ray source comprises protective case 7, is provided with X-ray tube 1, pallet 4, diaphragm 5 in this protective case 7, and described X-ray tube 1 has The exit window 11 is provided with a collimating part 9 on the protective box 7, and a plurality of fluorescent sheets 3 are provided on the tray 4, and each fluorescent sheet 3 is a different type of simple metal sheet with a thickness of tens of microns to ranging from hundreds of microns. The X-rays emitted from the exit window 11 pass through a piece of fluorescent sheet 3 , then emit fluorescent X-rays, pass through the diaphragm 5 and the collimating component 9 , and then exit the protective box 7 .

Please refer to Fig. 1 and Fig. 2, there is a ray tube support column 2 inside the protective box 7, and the ray tube support column 2 is an aluminum bracket with locking screws for clamping the X-ray tube 1 and locking Hold its posture. The X-ray tube 1 is a metal-ceramic tube with a cylindrical tube body. The opening direction of the exit window 11 is downward, and the X-rays exit in a cone-shaped beam with a divergence angle of about 20°.

Please refer to FIG. 1 and FIG. 2 , the tray 4 is located right below the exit window 11 . In order to avoid introducing interference, the tray 4 is made of plexiglass material, and the tray 4 is a truncated prism with a regular polygonal structure. The number of fluorescent sheets 3 is the same as the number of edges of the tray 4, and each fluorescent sheet 3 is bonded separately on the On one side of the tray 4, when the fluorescent sheet 3 is irradiated by X-rays, it is excited to generate fluorescent X-rays. The outgoing direction of these fluorescent X-rays is arbitrary, but mainly in the forward direction, and only contains characteristic X-radiation (mainly including kα and kβ characteristic line), eliminating the influence of the bremsstrahlung of the X-ray tube 1. The included angle between the fluorescent sheet 3 and the X-rays emitted from the X-ray tube 1 is 45°, that is, the fluorescent X-rays emitted from the fluorescent sheet 3 strike toward the diaphragm 5 along the horizontal direction. And, be provided with the tray frame 8 that is used to support described tray 4 in described protection box 7, be provided with the motor that is used to drive described tray 4 to rotate on this tray frame 8, by controlling the work of this motor, make tray 4 Rotate to change the position of the metal sheets, and control one of the metal sheets to align with the exit window 11 of the X-ray tube 1 . Therefore, through the rotatable tray 4 and the fluorescent sheets 3 of different elemental metal materials arranged on the tray 4, the fluorescent X-rays that can be emitted by the present invention have monoenergetic characteristic radiation, and by changing the position of the fluorescent sheet 3, the It emits fluorescent X-rays with different energy points.

Please refer to Fig. 1 and Fig. 2, the aperture 5 is made of a lead plate, the thickness of the plate is about 5 mm, and it has a light hole, the diameter of the light hole is about 0.5 mm to 1 mm, and the light hole is located at the A piece of fluorescent sheet 3 directly below the exit window 11 faces directly. An electric translation stage 6 is arranged inside the protective box 7, and the electric translation stage 6 is an electronically controlled one-dimensional translation stage. The electric translation stage 6 is located between the tray 4 and the collimating part 9. It is an L-shaped structure, which is fixedly connected to the top of the electric translation platform 6 , and the diaphragm 5 can be driven by the electric translation platform 6 to approach or move away from the fluorescent sheet 3 . Fluorescent X-rays must pass through the aperture of the diaphragm 5 before being directed to the collimating component 9, so that the fluorescent X-rays form an approximate point emission effect, thereby making the spatial distribution of the emitted monoenergetic fluorescent X-rays more uniform.

Please refer to Fig. 1～Fig. 3, described collimating part 9 is the flange plate made of lead, and it is fixedly installed on the protective box 7 by bolt 91a, and the center position of this collimating part 9 has collimating hole 91, and this collimating part 9 The straight hole 91 is formed by a hollow cylindrical member, the diameter of the hollow is about 10 mm, and the length is about 50 mm. Fluorescent X-rays that pass through the light hole 51 of the diaphragm 5 and are approximately point-emitted pass through the collimating hole 91 of the collimating component 9, and the collimated fluorescent X-rays exit the protective box 7 from the collimating hole 91 and pass through the collimating hole 91. Adjusting the position of the diaphragm 5 can change the divergence angle and intensity of the fluorescent X-rays emitted from the protective box 7 .

Please refer to Fig. 1 and Fig. 2, described protective case 7 adopts the double-layer structure of iron plate and lead plate, and total thickness is 20～30 millimeters, and wherein, inner layer adopts lead plate, thickness is about 6 millimeters, can shield X-ray, improves Equipment safety, the outer layer is made of iron plate, which makes the protective box 7 durable and protects the internal parts. And, there is a cable hole 71 on the protective box 7, and the pipeline 12 of the X-ray tube 1 passes through the cable hole 71. The pipeline 12 can be composed of a high-voltage cable and a cooling water pipe, so that it can Lead out from the cable hole 71.

For the concept of energy points, please refer to patents: CN201420580012.1, CN201210425897.3, paper: "Manufacturing Technology of Multi-Energy Point X-ray Transmission Grating" in "Micro-Nano Electronics Technology", Volume 47, No. 1 (January 2010) ".

Finally, it should be noted that the above description is only a preferred embodiment of the present invention, and those of ordinary skill in the art can make a variety of similar implementations under the inspiration of the present invention without violating the purpose and claims of the present invention. It means that such transformations all fall within the protection scope of the present invention.

Claims (7)

1. a kind of adjustable x-ray source, including protective housing (7) and the X-ray tube (1) that is arranged in the protective housing (7), its feature It is：Rotatable pallet (4) and moveable diaphragm (5) are provided with the protective housing (7), on the protective housing (7) Provided with collimating components (9), there is exit window (11) on the X-ray tube (1), at least two pieces are provided with the pallet (4) Flourescent sheet (3), the X ray of exit window (11) outgoing are anti-backward by flourescent sheet (3), diaphragm (5) and collimating components (9) successively Protecting box (7) is emitted outside, and the flourescent sheet (3) is elemental metals material, and the fluorescence X of one piece of flourescent sheet (3) outgoing is penetrated therefrom Line can put the energy point for being more than or less than the fluorescent X-ray from the outgoing of remaining any block flourescent sheet (3)；

The diaphragm (5) has a light hole, a diameter of 0.5 millimeter~1 millimeter of the light hole；

The tray rack (8) for being used for supporting the pallet (4) is provided with the protective housing (7), is provided with and uses on the tray rack (8) In the motor for driving the pallet (4) to rotate；

The motorized precision translation stage (6) for being used for making the close or remote pallet (4) of the diaphragm (5) is provided with the protective housing (7).

2. adjustable x-ray source according to claim 1, it is characterised in that：The opening direction court of the exit window (11) Under, the pallet (4) is located at the underface of exit window (11), the diaphragm (5) be located at pallet (4) and collimating components (9) it Between.

3. adjustable x-ray source according to claim 2, it is characterised in that：The pallet (4) is prismatic table shape, the fluorescence Piece (3) is each positioned on a side of the pallet (4).

4. according to adjustable x-ray source according to any one of claims 1 to 3, it is characterised in that：In the protective housing (7) Provided with the ray tube support column (2) for supporting the X-ray tube (1).

5. according to adjustable x-ray source according to any one of claims 1 to 3, it is characterised in that：The collimating components (9) are The ring flange of lead, the center of the collimating components (9) have collimating aperture (91).

6. adjustable x-ray source according to claim 1, it is characterised in that：The protective housing (7) is using iron plate and stereotype Double-decker, wherein, internal layer uses stereotype, and outer layer uses iron plate.

7. the adjustable x-ray source according to claim 1 or 6, it is characterised in that：There is cable hole on the protective housing (7) (71), the pipeline (12) of the X-ray tube (1) passes from the cable hole (71).