CN110881279A - Stretcher of wire electrode ion control device and wire tension control method - Google Patents

Abstract

The invention discloses a stretcher of a wire electrode ion control device and a wire tension control method, which are used for ion generation, transmission and mass analysis. The invention can directly generate ions in the ion trap, capture and trap the generated ions by utilizing the wire electrodes arranged in space, and directly transmit the ions to the mass analyzer with extremely low loss to obtain the mass spectra of the ions with different masses. The tension of the wire is adjusted through the stretcher, the tension of the wire is kept consistent by measuring the sound frequency of the stirred wire, and the optimization of the formed ion hydrazine electric field is ensured. Therefore, the invention has small structure, flexible detection means and easy operation, and is suitable for manufacturing and detecting the wire electron ion hydrazine.

Description

A kind of wire electrode ion control device stretcher and wire tension control method

technical field

The present invention relates to the technical field of ion manipulation and analysis devices. In particular, it relates to an adjustment measurement device and method for wire electrodes.

Background technique

Mass spectrometers play an important role in modern analytical chemistry due to their fast, excellent identification capabilities, high sensitivity and high resolution. However, mass spectrometers are relatively bulky, and their disadvantages, such as heavy weight, high power consumption, and complex manufacturing and maintenance, hinder their wider application. In applications such as public safety, environmental protection, biochemical analysis, and industrial process monitoring, there is a need for small, portable mass spectrometers with good performance. A miniature mass spectrometer is one of the best solutions for these applications because of its field-deployable advantage and superior ability to identify unknown compounds. However, current miniature mass spectrometry techniques cannot meet the detection sensitivity requirements for these applications. For example, the current sensitivity of detecting explosive compounds with miniature mass spectrometers is ppb level, while airport security inspection requirements need to be ppt level or better. Ion traps are one of the best options for miniaturizing mass spectrometers because of their compact size, relatively high operating pressures, and unique capabilities for multi-stage tandem mass analysis (MSn).

According to the structure, ion traps include three-dimensional ion traps and two-dimensional linear ion traps. The three-dimensional ion trap consists of a pair of ring electrodes and two end cap electrodes in the shape of a hyperboloid. Three-dimensional ion traps were originally disclosed by Paul and Steinwedel in US Pat. No. 2,939,952. A radio frequency voltage RF or a direct current voltage DC is applied to the ring electrode, and the upper and lower end cap electrodes are grounded. Gradually increasing the maximum value of the RF voltage, the ions enter the unstable region and are discharged from the small holes on the end cap. Therefore, when the highest value of the radio frequency voltage is gradually increased, ions with increasing mass-to-charge ratios are successively discharged and recorded to obtain a mass spectrum. In the three-dimensional ion trap, due to the limited space used, the space charge effect is obvious, and the storage capacity of ions is limited, which limits the resolution of the mass spectrometer and the linear range of ion detection, thereby affecting the sample analysis performance.

To solve these problems, US Patent No. 6,797,950 proposes a two-dimensional ion trap, also known as a linear ion trap, which is very similar to a quadrupole mass spectrometer and consists of two sets of hyperbolic rods and two flat plates at each end. Alternating RF voltages are applied to one set of diagonal hyperbolic rods, while alternating RF voltages with a 180-degree phase difference are applied to the other set of diagonal hyperbolic rod electrodes. Meanwhile, by superimposing another weak alternating voltage with a 180° phase difference on a set of diagonal hyperbolic rod electrodes, a dipole resonance-assisted excitation mode can be realized. This mode greatly improves the ion extraction efficiency and mass resolution of the ion trap.

In the electric field formed by the linear ion trap, in the ion excitation or expulsion direction X, the bound potential component function V(x)=Ax2 in this direction that the ions are subjected to, that is, it is a quadratic field in this direction, or a simple harmonic potential well. function, the oscillation frequency of the ion moving in this direction is independent of the resonance amplitude.

The four hyperbolic rod electrodes are arranged in parallel to form an ion trap, and one of the hyperboloid electrodes needs to be opened with a small hole, so that the resonant ions can be emitted through the small hole. Compared to a three-dimensional ion trap, the trapped ions are significantly increased, which can improve detection sensitivity. However, such a two-position linear ion trap requires very sophisticated machining machinery to form the required precise hyperbolic rod electrodes and is therefore costly. In addition, the aperture on the hyperbolic rod is not large enough, which blocks the exit of a part of the ions, limiting the further increase in sensitivity.

In order to overcome the above shortcomings, many efforts have been made to replace the hyperbolic rod electrodes with simplified electrodes and pursue acceptable detection performance. US Patent 6,838,666 describes a system and method for a linear ion trap mass analyzer, the ion trap being formed from simple rectangular electrodes. A more direct approach is to modify the boundary structure of the ion trap confinement electrodes. This method makes the confinement electrode in the ion exit direction relatively protruding at the ion exit, as detailed in the solution proposed by River Rat in US Pat. No. 6,087,658. In addition, methods of increasing the distance between a pair of ideal quadrupoles are also widely used. The localized electric field can also be improved by partially replacing the original confinement electrodes with multiple discrete electrodes while applying different confinement voltages to these discrete replacement electrodes. For the linear ion trap, in Chinese patent CN1585081, Ding Chuanfan designed a linear ion trap surrounded by a printed circuit board. The structure includes a plurality of discretely adjustable electrode strip patterns. He used the capacitor-resistor network of voltage dividers to adjust the RF voltage and the limiting DC voltage between these electrode patterns. Similarly, electrostatic ion traps with axial secondary fields can also be constructed as pointed out in US Patent No. 7,755,040 to Gangqiang Li et al. One of the inventors of this patent, Wu Qinghao et al., used stainless steel wire electrodes to generate secondary fields and obtained better resolution (see Journal of Analytical Chemistry, Vol. 88, 2016, pp. 7800-7806, and Journal of the American Society for Mass Spectrometry, 2017). ).

Wu Qinghao et al. used a stainless steel electrode to generate a secondary field and obtained a better resolution (Anal.Chem.2016, 88, 7800-7806; J.Am.Soc.Mass Spectrom.(2017)). The conductive wire electrode ion trap has the characteristics of small capacitance, good resolution and easy processing, which is of great value in the miniature ion trap. But there are still many problems. These problems include: 1. The electrode of the conductive wire cannot be effectively stretched and fixed, resulting in bending of the metal wire and affecting the electric field. 2. Using a symmetrical field, the ions are emitted from two directions evenly when they are emitted. If only one detector is used, half of the ions will not be detected, thus reducing the sensitivity. The use of two detectors will increase the cost, and there are a series of problems such as signal combining. 3. Using the electrostatic field to transfer ions from the VUV lamp ion source to the ion trap, the loss of ions is large, which affects the sensitivity.

SUMMARY OF THE INVENTION

The technical problem solved by the present invention is to provide a wire electrode ion control device stretcher and a wire tension control method to improve the ion detection sensitivity, which can greatly improve the consistency of the tension force of each wire in the wire electrode, so that the Improvement of the ion trap electric field.

The technical scheme adopted in the present invention is that a wire electrode ion control device stretcher includes at least two support cylinders, a perforated insulating plate, a wire electrode, a wire stretcher and an ion detector. The perforated insulating plate is sealed and matched to form a cavity, a group of wire electrodes is arranged in the cavity, a center hole is arranged in the center of the perforated insulating plate, a metal ring is arranged on the center hole, and a support cylinder and a supporting cylinder are arranged between two adjacent perforated insulating plates. A set of wire electrodes, the number of each set of wire electrodes is at least 4, each wire electrode includes at least 2 wires parallel to each other, the perforated insulating plate is provided with a surrounding hole, and the two ends of the wire pass through and are fixed on the front and rear respectively. on a surrounding hole in a perforated insulating plate;

The perforated insulating plate is connected with a tensioner for adjusting the tension of the wire. The tensioner includes a tension bolt and a fixing bolt. The tension bolt connects the wire. With the screwing of the tension bolt, the tension of the wire changes, and the tension After the tension adjustment is completed, clamp the tension bolt with the fixing bolt, and tighten the position of the tension bolt.

The tension bolt is a hollow bolt, and the wire passes through the through hole in the hollow bolt and is fixed on the tension bolt.

The axis of the fixing bolt is perpendicular to the axis of the tension bolt, and the fixing bolt bears the side of the tension bolt to fix the tension bolt.

The tensioner also includes a wire fixing frame, the wire fixing frame and the perforated insulating plate are fixedly connected, the wire fixing frame is provided with threaded holes, and the stretching bolts are installed in the threaded holes.

The tensioner also includes a fixing block and a bolt on the fixing block, the wire is clamped to the fixing block through the bolt, and the fixing block is sleeved on the tensioning bolt.

The wire fixing frame is a round or square frame, the frame is provided with through holes connecting the inside and outside, and the wires pass through the through holes.

The wire fixing frame is provided with a groove, and the fixing block is located in the groove.

Each lead electrode is formed by passing the same metal wire back and forth through the corresponding surrounding hole, and the lead tension of each lead electrode is adjusted by a tension bolt.

The device comprises at least three perforated insulating plates, the center of the perforated insulating plates is provided with a central hole, a metal ring is arranged on the central hole, a support cylinder and a group of wire electrodes are arranged between two adjacent perforated insulating plates, and each group of wires The number of electrodes is at least 4, and each wire electrode includes at least 3 wires parallel to each other, the perforated insulating plate is provided with a surrounding hole, and the two ends of the wire are respectively passed through and fixed to the surrounding holes on the front and rear perforated insulating plates On the upper side, the support cylinder encloses the wire electrode and seals with the front and rear two perforated insulating plates to form a cavity; the perforated insulating plate is connected with a tensioner for adjusting the tension of the wire, and the tensioner includes a tension bolt and a fixing bolt , The tension bolt is connected to the wire. With the screwing of the tension bolt, the tension of the wire changes. After the tension is adjusted, the tension bolt is clamped with the fixing bolt to fasten the position of the tension bolt;

Twist the tension bolt, apply tension to the wire, move each wire, measure the frequency of the sound emitted by each wire with a sound frequency tester and record it, take the frequency value as the reference value, and 500Hz above and below the reference value is qualified Adjust the tension bolt corresponding to the corresponding wire, loosen the wire whose pronunciation frequency is higher than the qualified range, continuously measure its pronunciation frequency until its pronunciation falls within the qualified range, tighten the wire whose pronunciation frequency is lower than the qualified range, and continuously measure its pronunciation frequency until its pronunciation falls within the acceptable range.

The optimization of the electric field is essential for any ion trap design and needs to be optimized by varying various geometrical parameters. Computer simulations provide an efficient way to test the impact of design changes in geometric parameters and minimize labor and R&D costs. Usually we use the following two methods to predict the performance of the ion trap: 1) Calculate the higher-order components of the electric field and compare with the parameter values of the existing ion trap. However, this method is not ideal for optimizing ion trap geometry due to the arbitrary nature of parameters such as the boundaries of the electric field and the degree of polynomial curve fit. 2) Use computer simulation to estimate the detection performance of the ion trap, eg, mass resolution, ion extraction efficiency, etc. This method provides a direct method to evaluate the performance of the ion trap geometry, so it can be used as an effective method for optimizing the geometric parameters of the ion trap. The disadvantage of this method is that it is computationally expensive. However, tremendous advances in computing technology in recent years have made this obstacle largely overcome. In previous work [International Journal of Mass Spectrometry 393:52-57. ], the inventors of the present application demonstrate the use of a single-parameter optimization method to study the problem of misalignment in a two-plate linear ion trap (LIT), optimizing only one geometric parameter at a time. However, the geometry of the ion trap electrodes should vary in several ways, in which case multi-parameter optimization is required. We optimized with computer simulations based on resolution and peak height as criteria, ie optimizing six parameters simultaneously in a linear ion trap. A test system was then constructed based on the optimized geometry, and the experimental results were used to evaluate the stability map, resolution and sensitivity of the linear ion trap.

The beneficial effects of the present invention are that the ion transmission efficiency can be improved by connecting the ion control chambers in series, and good resolution can be achieved. Small size. The stretching operation of the wire is easy, and the stretching force can be basically kept the same. The consistency of the tension force of each wire enables the actually generated electromagnetic field to fully realize the simulated electromagnetic field state.

Description of drawings

Figure 1 is an embodiment of a wire electrode ion trap of the present invention.

FIG. 2 is a structural diagram of the insulating plate and the lead electrode in FIG. 1 .

Figure 3 is a perspective view of a perforated insulating panel of the present invention.

Fig. 4 is another drilling method of the porous insulating plate of the present invention.

FIG. 5 is the ion extraction effect in the symmetrical surrounding hole structure of the present invention.

FIG. 6 is the ion extraction effect in the asymmetric surrounding hole structure of the present invention.

FIG. 7 is a structural diagram of the wire electrode tensioner of the present invention.

FIG. 8 is another structural diagram of the ion control device in the present invention.

FIG. 9 is another structural view of the surrounding holes in the perforated insulating plate of the present invention.

FIG. 10 is a structural view of another ion control device of the present invention.

FIG. 11 is a structural diagram of another wire lead tensioner of the present invention.

Figure 12 is a view of the construction of various embodiments of the wire guide tensioner of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with schematic diagrams and specific implementation cases.

VUV lamps are ultraviolet lamps.

Example 1, as shown in Figures 1-7.

In the selected implementation case, as shown in FIG. 1, three ion control devices are connected in series, and the whole device includes four perforated insulating plates, wherein the first perforated insulating plate 101a, the second perforated insulating plate 101b and the supporting cylinder are 103a constitutes a perforated insulating plate, and the third perforated insulating plate 101c, the fourth perforated insulating plate 101d and the support cylinder three 103c constitute another similar ion capture chamber. The second perforated insulating plate 101b, the third perforated insulating plate 101c and the second support cylinder 103b constitute an ion analysis chamber. It also includes a group of wire electrodes 102 surrounded by each support cylinder, an ultraviolet lamp ionization device, namely a VUV lamp, an electron gun ionization source 106, a buffer gas inlet pipe 107, a sample inlet pipe 108a and a sample inlet pipe 2 108c. Both ends of the device are also provided with wire electrode stretchers 118a.

In operation, the wire electrodes in each ion trap chamber and ion analysis chamber are composed of a plurality of parallel metal wires, and different electrical signals are applied to the wire electrodes of the ion capture chamber and ion analysis chamber to form different ion traps, VUV Lamp one 105a, VUV lamp two 105c or electron gun ionization source 106 generate ions in the corresponding ion trapping chambers. The generated ions are trapped in the ion trap chamber and an AC voltage is applied to the wire electrodes. When the voltage on the ring electrode in the central hole of the perforated insulating plate is changed, the trapped ions pass through the central hole and are transferred to the ion analysis chamber between the second and third perforated insulating plates, as in Figure 2 211 shown.

During operation of the ion trap, an ionization source consisting of VUV lamp one 105a and VUV lamp two 105c or electron gun ionization source 106 can generate ions in the ion trap chamber. There are three mechanisms by which ionization sources generate ions, electron ionization, photoionization, and chemical ionization. The electron gun ionization source 106 includes a thermionic emitting filament that generates electrons, and a voltage of 70V DC is applied to the filament to accelerate the electrons to 70eV. The collision of these electrons with sample molecules will generate positive ions in the ion trap chamber. The high-energy photons emitted by the VUV lamp of the photoionization source can directly cause the soft ionization of the sample molecules, and can also generate electrons on the surface of the metal cylinder constituting the ion trap chamber through the photoelectric effect, and the sample molecules can also be softly ionized after being accelerated by the electric field. . In the first embodiment, the photon energy generated by the first VUV lamp 105a may be the same as or different from the photon energy of the second VUV lamp 105c. If the photon energies from the two lamps are different, compounds with different ionization energies can be distinguished by comparing the difference between the ions generated by the two VUV lamps, which is more efficient for sample detection and comparison. Chemical ionization uses auxiliary chemical reagent molecules in the ion trap, such as gaseous molecules such as acetone and xylene, to generate electrons and positive ions through photoionization. Because the air pressure in the ion trap chamber can reach several tens of Pa, there is enough time for ideal The ion molecules react to generate the corresponding positive and negative ions of the analyzed sample. Other possible ionization methods are tip discharges, such as glow discharges or corona discharges, as well as hot cathode electron emission sources. In the present invention, the VUV lamp is preferred as the ionization source, which has a good soft ionization effect. At the same time, since the wire electrode is composed of several extremely thin metal wires, the shielding of ultraviolet light can be ignored, and the ionization effect of the sample gas is very good.

Once the ions are generated within the ion trap chamber, they are trapped by an electric field created by a set of wire electrodes (102) to which an alternating current signal is applied. The structure of the wire electrode is shown in Figure 2. The trapped ions are cooled after multiple collisions with the buffer gas. After a short period of time, ions are transferred to the analysis chamber by a pulsed voltage applied to center electrode two 218b or center electrode three 218c located on center hole two 211b, or center hole three 211c, as shown in FIG. 2 . Under the containment of the AC electric field, the loss of ions in the process of transmission and transfer is very small, which significantly improves the detection sensitivity of the system. Since the loss is reduced by an order of magnitude, the demand for samples is greatly reduced, and the detection can be realized when the sample volume is too small to be detected, which greatly improves the detectable application range. There is no need to consume a lot of power in order to generate a large number of ions like the existing equipment, and it gets rid of the huge ion generation and capture device, and the ion transmission is also very efficient. Completed in a vacuum environment, the power consumption of the entire device is greatly reduced, the volume is very small, it is very easy to carry to on-site testing, there is no need to collect and transfer samples, and it is more efficient in time and more flexible in space.

As shown in FIG. 1 , four alignment holes 120a, 120b, 120c and 120d are provided on each insulating plate, so that the positions of the perforated insulating plates 101a, 101b, 101c and 101d can be easily determined. During assembly, the position of the perforated insulating panel can be precisely determined and maintained by position alignment with rigid rods passing through alignment holes.

As shown in FIG. 1, the buffer gas is introduced into the ion analysis chamber through the buffer gas inlet pipe 107, and the sample gas is introduced into the two ion trap capture chambers from the first sample inlet pipe 108a and the second sample inlet pipe 108c, respectively. The separate introduction of these two gases overcomes the problem of pressure imbalance in the original design Anal.Chem. 2016, 88, 7800-7806; J.Am.Soc.Mass Spectrum. 2017. This method can increase the sample gas flow, thereby improving the sensitivity of the system. The slit 121 on the side wall of the square sleeve of the ion analysis chamber is used to emit ions, and the emitted ions can be detected by the ion detector 109 .

One or more groups of VUV lamp ionization devices are respectively installed on both sides of the first support cylinder 103a and the third support cylinder 103c. Photons emitted by the VUV lamp are radiated through the aperture 112 into the support cylinder, ionizing the sample molecules. Multiple sets of VUV lamp ionization devices improve the ionization efficiency, thereby increasing the sensitivity of the system. In practice, VUV lamps of different wavelengths can also be used to obtain distinguishable mass spectra. For example, shorter wavelength VUV lamps are capable of ionizing most organic compounds. The use of VUV lamps with slightly longer wavelengths can only effectively ionize compounds with lower ionization energies. By comparing the two sets of mass spectra, the difference in ionization energy of compounds in the sample gas can be distinguished, so as to obtain the type information of the compounds.

Fig. 2 shows the structure of the perforated insulating plate and the wire electrode in Fig. 1, in which the first support cylinder 103a, the second support cylinder 103b, and the third support cylinder 103c are removed for better display. Four perforated insulation boards, perforated insulation board 1 201a, perforated insulation board 2 201b, perforated insulation board 3 201c and perforated insulation board 4 201d are connected by three groups of metal wires at the front and back, and the three groups of metal wires respectively constitute the front wire electrode 202a, the middle The lead electrodes 202b and the rear lead electrodes 202c have the same distribution of the lead electrodes in each group, and can communicate with each other before and after. The center hole and multiple groups of surrounding holes 212a, 212b, 212c, 212d around the center hole are distributed on the perforated insulating plate, and metal wires belonging to the same wire electrode are fixed on each group of surrounding holes. Metal rings 218a, 218b, 218c, 218d at the center of each perforated insulation plate are tightly fixed in the central holes 211a, 211b, 211c and 211d of each perforated insulation plate to control the transmission of ions along the axis of symmetry 221. The ion trap electric field is created by applying an AC voltage signal to the wire electrodes. The ions are trapped in the trapping region formed by wire electrode one 202a, wire electrode two 202b, wire electrode three 202c, center metal ring two 218b, and center metal ring three 218c. In the figure, the wire electrodes before and after each perforated insulating plate may not be connected to each other. At the same time, the ion trap electric fields formed by the wire electrodes in the front and rear support cylinder cavities can be different, which can be used for various detection and comparison methods. . The connection method of the wire electrodes between the perforated insulating plates is shown in Figure 3. The wires belonging to the same wire electrode are formed by the same metal wire folded back and forth through the corresponding surrounding holes, which simplifies the wire fixing method and facilitates the application of voltage signals. A series of positioning calibration holes 220a, 220b, 220c, 220d are used to confirm the position of the perforated insulating plates 201a, 201b, 201c, 201d.

The support cylinders are inserted into the grooves 214b, 214c, 214d in the perforated insulating plates 201a, 201b, 201c and 201d, one of which is blocked and not visible in FIG. 2 . The width of the groove is slightly larger than the wall thickness of the support cylinder, so that the support cylinder can be tightly fixed, and at the same time, it has a sealing effect. Since the entire device is placed in a vacuum environment, this sealing of the support cylinder and perforated insulating plate, combined with the very small size of the surrounding holes, center holes, ion exit holes, etc., ensures that there is an order of magnitude between the inside and outside of the ion trap chamber pressure difference. To achieve better resolution, the optimum gas pressure inside the ion trap is about 0.1 to 0.5Pa, and the gas pressure outside the ion trap is about 0.01Pa. To maintain this differential pressure, the seal design of the present invention can meet this requirement. In addition, better sealing also reduces buffer gas consumption, reducing operating costs. The grooves on PIP one 201a and PIP four 201d at both ends of the device are made on one side, while the grooves on those PIP two 201b and PIP three 201d in the middle of the device need to be made on both sides .

There are three types of holes in perforated insulation boards. As shown in Figure 3. The first type of hole is a central hole 311 , and a metal ring is mounted on the central hole 311 . The application of an appropriate DC voltage to the metal ring can control ion transport along a central axis parallel to the wire electrodes. The second type of hole is a surrounding hole, which is used to pass the wire electrode. Four such holes form a group, a total of four groups of surrounding holes, a first surrounding hole 312a, a second surrounding hole 312b, and a third surrounding hole 312c and a fourth surrounding hole 312d. The wires passing through the same set of surrounding holes are connected to each other, and the same voltage signal is applied to become a wire electrode. The location of the surrounding holes may be symmetrical or asymmetrical relative to the central location. The third type of holes are alignment holes 320 for aligning the positions of these perforated insulating plates, these alignment holes being symmetrical to the center of the plate.

The position of the surrounding hole can be determined by the calculation of the simulation software. On the two-dimensional plane, the position of each hole has two position parameters. For symmetrical structures, the location of the symmetrical holes can be determined by the symmetry. In the simulation software, mass spectra were acquired by simulating thousands of ion runs in the device, and the positions of these pinholes were optimized according to the resulting mass spectral resolution and sensitivity. Based on these criteria, the location of these pinholes can be completely determined. For example, in a symmetrical implementation using 16 holes, as shown in Figure 3, the positions of the four holes are (6.7, 0.7), (6.8, 3), (1.5, 7), (4.5, 7), The center of the central hole is set to (0,0), and the rest of the surrounding holes are positioned according to the principle of center symmetry. For an asymmetric structure, as shown in Figure 4, the positions of all these surrounding holes need to be calculated separately. The size of the ion trap can be scaled very easily according to actual needs. The wire electrode is formed through the surrounding hole, and the machining accuracy of the surrounding hole is only 0.1mm, while the machining accuracy of the existing quadruple rod needs to reach the micron level, which is difficult to process, extremely expensive to process, and has a high processing cost. It cannot be changed after molding, and the wire electrode can flexibly replace the perforated insulating plate, and use different surrounding holes to form different ion traps, which is more industrially practical.

Definition: AV signal refers to a high-voltage alternating electrical signal with an amplitude between 50V and 10000V, and an AC signal refers to a low-voltage alternating signal with an amplitude of 0-10V and a frequency of about one third of the AV amplitude. and can be adjusted.

In FIG. 3, the same high-voltage alternating electrical signal AV is applied to the opposite two groups of wire lead electrodes, such as the second lead electrode 316b and the fourth lead electrode 316d. On another pair of opposite two groups, such as the first wire electrode 316a and the third wire electrode 316c, the high voltage alternating electrical signal AV with a phase difference of 180° is applied to the wire wire electrode. This alternating high-voltage electrical signal AV provides a trapping electric field for the trapped ions. The amplitude of the high voltage alternating electrical signal is between 50V and 10000V. In addition, alternating AV signals with signal amplitudes less than 10V are superimposed to the wire electrodes in hole 316a. At the same time, an electrical signal with the same amplitude, which is 180 degrees different from that on the first wire electrode 316a, is applied to the third wire electrode 316c. Similarly, this low voltage alternating AC signal may also be superimposed on the second wire electrode 316b and the fourth wire electrode 316d. In addition, in addition to applying the low-voltage AC signal, a constant potential difference of less than 10V needs to be applied to the first wire electrode 316a and the third wire electrode 316c, which can help positive ions and negative ions to exit from the ion trap in opposite directions.

FIG. 4 shows another distribution structure of holes of the perforated insulating plate. In this structure, there is a central hole 411 in the central area of the perforated plate. There are 6 groups of 3 surrounding holes, and each group of surrounding holes 412a, 412b, 412c, 412d, 412e, 412f is distributed around the central hole 411. The high voltage alternating voltage signal AV is applied to the wire electrodes passing through the first surrounding hole 412a, the third surrounding hole 412c and the fifth surrounding hole 412e. The high voltage alternating voltage signal AV having the same amplitude and 180 degree phase difference is applied to the wire electrodes passing through the second surrounding hole 412b, the fourth surrounding hole 412d and the sixth surrounding hole 412f. The amplitude of the high voltage alternating voltage signal AC is between 50V and 10000V. The AV signal so applied can create a confinement electric field in the cavity for trapping ions. The principle of the design is to use the electric field formed by six groups of wire wires, similar to the electric field in a hexapole ion transporter, as an ion transport device. Therefore, based on the same principle, the electric fields in octopole ion transporters and other multi-electrode ion transporters can also be constructed in a similar way. The number of lead electrodes is an integer multiple of four or six.

The wire winding method in Fig. 3 can adopt the following method. A wire is folded between two perforated insulating plates three times to form four wires that are parallel to each other and become a wire electrode. The two ends of the wire can be At the same time, it is fixed on a wire tensioner, and the surrounding hole only plays the role of positioning, and the electric signal is applied to the wire to ensure that the same voltage signal is applied to each wire on the wire electrode. In Figure 4, each wire electrode is composed of three parallel wires. The wire can be wound in a way that a wire is folded between two perforated insulating plates twice. One end of this wire is connected to the wire tensioner, and the other One end is fastened to the perforated insulation board. The encircling hole also acts as a fixing. Another way of winding can also be used. Two wire electrodes that need to apply the same voltage signal are folded back five times by the same wire to form six parallel wires to form two wire electrodes. Note that the wire avoids the end electrodes. The metal wire is very thin, and there is no friction between it and the surrounding hole. The more times the same wire is folded back, the advantage is that the consistency of the wire tension is stronger. The disadvantage is that the wire tension will be more sensitive to the response of the tensioner. If the extension bolt moves slightly, the movement of the wire will be magnified more times. When adjusting the tension force, you need to be more careful, and the fixation of the extension bolt needs to be more stable.

Figures 5 and 6 illustrate the difference between the surrounding pore distribution for symmetric structures and the surrounding pore distribution for asymmetric structures. In the symmetrical surrounding hole structure of Figure 5, most ions are emitted equally from two opposite sides. However, in the asymmetric surrounding hole structure in FIG. 6 , due to the movement of the surrounding hole positions, the surrounding hole positions become asymmetrical with respect to the central axis, so that the effect of ion extraction in one direction can be obtained. This design of asymmetric surround apertures can yield more parameters to optimize the performance of the ion trap. Because of the asymmetry, the position of each hole increases by two parameters, which can better optimize the performance, and one ion detector can be eliminated, which not only reduces the cost, but also improves the detection sensitivity of the mass spectrometer. Reference numeral in Fig. 5, positioning hole-520, reference numeral in Fig. 6, positioning hole-620.

Figure 7 shows the stretcher for the wire electrode. The design includes a wire retention frame 718 and some cannulated bolts 719. The wire fixing frame 718 is provided with a set of threaded holes 720 . The axis of the threaded hole 720 is at an angle of 0° to 90° with respect to the plane of the fixing plate 701 . In the case of insufficient space, using multiple angles can effectively utilize the space. Hollow bolts are installed in threaded holes 720 . Each wire electrode passes through a through hole in the center of a hollow bolt 719 where the wire electrode is knotted or welded. The pulling force exerted on the wire electrode can be determined by adjusting the rotational position of the hollow bolt 719 . This design is simple and easy to use, and the tension can be adjusted individually for each wire electrode, which solves the problem of uneven wire electrode tension in the original design.

Since the wire is very thin, the tension force changes very sharply, and the consistency of the wire tension force is very important to the electric field of the ion trap. Toggle each wire, use a sound frequency tester to measure the frequency of the sound emitted by each wire and record it. It is preferred to set a reference value. The reference value can be selected as a reference value according to the frequency measured by each wire. You can set a reference value considering the length of the wire and factors. The upper and lower 500Hz of the reference value is the qualified range. Adjust the tension bolts corresponding to the corresponding wires, loosen the wires whose pronunciation frequency is higher than the qualified range, and continuously measure the pronunciation frequency until its pronunciation frequency. If it falls within the qualified range, tighten the wire whose pronunciation frequency is lower than the qualified range, and continuously measure its pronunciation frequency until its pronunciation falls within the qualified range.

Implement Case 2, as shown in Figures 8 and 9.

FIG. 8 shows the structure of another ion control device. The structure uses three perforated insulation boards, a first perforated insulation board 801a, a second perforated insulation board 801b, and a third perforated insulation board 801c, with positioning and alignment holes 820 and several groups of surrounding holes 812 on the board. The wire electrodes between the first perforated insulation plate 801a and the second perforated insulation plate 801b form the ion capture chamber 803 , and the wire electrodes between the second perforated insulation plate 801b and the third perforated insulation plate 801c constitute the ion mass analysis chamber 804 . In the ion trap chamber, the surrounding hole distribution pattern of the first insulating plate 801a is similar to that shown in FIG. 4 . In this design, the wire electrodes in the ion trap chamber and the ion trap mass analysis chamber are independent of each other and are connected by a second perforated insulating plate 801b shown in FIG. 9 . This design utilizes the surrounding pore distribution structure in Figure 4, and has a relatively large ion mass range, which can increase the mass range of trapped ions.

The ion control chambers of the first perforated insulating plate 801 and the second perforated insulating plate 801b can also be used as ion molecule reaction chambers, where ions are introduced from external equipment and react in the ion molecule reaction chamber,

Figure 9 shows a configuration of the surrounding holes of the perforated insulating plate connecting two ion control devices. The central hole is located in the central area, and the surrounding small holes are composed of two sets of small holes of different sizes and positions. There are six groups, three in each group; the other set of rear surrounding holes 912a, 912b, 912c, 912d are used to install the wire electrodes of the back-end ion analysis chamber, which are divided into four groups, three in each group. The three metal wires passing through the same group of surrounding holes are a wire electrode, and the same voltage is applied, and the voltages applied by the adjacent wire electrodes belonging to the same ion control chamber have a phase difference of 180°. The details are as follows: two sets of AV signals with a phase difference of 180 degrees but the same amplitude are respectively applied to the wire electrodes passing through the front surrounding holes 913a, 913c, 913e and the wire electrodes passing through the front surrounding holes 913b, 913d, 913f superior. Similarly, AV signals having a phase difference of 180 degrees but the same amplitude are applied to the wire electrodes passing through the rear surround holes 912a, 912c and the wire electrodes passing through the surround holes 913b, 913d, respectively. The distribution of these surrounding holes can be symmetrical or asymmetrical with respect to the center of the perforated insulating plate, as shown in FIGS. 5 and 6 . Reference may be made to the descriptions with respect to FIGS. 3 and 4 for the winding method of the metal wires in FIG. 9 . In this embodiment, there are two wire tensioners, which are respectively installed on the first perforated insulating plate 801a and the third perforated insulating plate 801c, and are used to adjust the wire electrode tension of the ion capture chamber 803 and the ion mass analysis chamber 804 respectively. tight. The detection and adjustment of the wire electrode tension force is the same as the adjustment method in the first embodiment.

Implement Case 3, as shown in Figures 10 and 11.

FIG. 10 shows the structure of another ion control device. In selected embodiments, three ion control devices are connected in series. The first perforated insulating plate 1033a and the second perforated insulating plate 1033b constitute the ion capture chamber; the second perforated insulating plate 1033b and the third perforated insulating plate 1033c constitute the ion transmission chamber; the third perforated insulating plate 1033c and the fourth perforated insulating plate 1033d constitute Ion analysis chamber. Two through holes are provided on the sidewall of the first support cylinder 1036a to allow the ultraviolet light generated by the VUV lamps 1040a and 1040b to pass therethrough. A through hole 1038 is provided on the side wall of the second support cylinder 1036b to limit the air pressure in the cavity. A cutout is provided on the side wall of the third support cylinder 1036c to allow the exiting ions to pass through. The tensioner at one end includes a metal wire fixing frame 1041a and a set of fixing bolts 1037a thereon, which are used to adjust the tension force of the wire electrodes in the ion transfer chamber. The tensioner at the other end includes a metal wire fixing frame 1041d and a set of fixing bolts 1037d on it, which are used to adjust the tension force of the wire electrodes in the ion analysis chamber.

Figure 11 shows the structure of another wire tensioner. In selected embodiments, the tensioner includes a wire fixing frame 1140, a wire fixing block 1141 and a tension bolt 1142, and the advance and retreat of the tension bolt 1142 adjusts the tension force of the wire. Among them, the wire fixing frame made of insulating material is provided with three kinds of screw holes: reinforcement hole 1145 , wire hole 1146 and hole 1147 . The wire holes 1146 are used to pass the wires so that they can be fixed by the wire fixing blocks 1141 . The holes 1147 have internal threads for mounting the tension bolts 1142, which provide pressure to the wire fixing block 1141 by rotation. Although the thread has a certain degree of self-locking, the variable range of the tension force of the wire is very small. If one of the tension bolts moves slightly, it may cause a huge difference in the tension force of the wire electrode and affect the tension force of the wire electrode. For consistency, the reinforcement holes 1145 are used for mounting bolts to push up the tension bolts 1142 to prevent movement of the wire tension bolts 1142 . The wire fixing block 1141 has a through hole 1142 and a threaded hole 1143 , the metal wire passes through the through hole 1142 and is fixed by a bolt 1148 and is installed in the threaded hole 1143 . The groove 1102 is used to maintain the position of the wire fixing block 1141 . The wire is connected to the wire fixing block, then in the process of stretching, the twisting of the tension bolt can only affect the tension of the wire, and the wire will not be twisted by itself, and the wire will be more straight and stretched. It is beneficial to form a more ideal ion trap electromagnetic field.

The wire tensioner of the wire electrode in the ion transfer chamber can be installed on the second perforated insulating plate 1033b or the third perforated insulating plate 1033c to adjust the wire tension of the wire electrode in the ion transfer chamber. The wire tensioner in the transmission chamber cannot adopt the same structure as the tensioner at both ends, then a simplified structure can also be used, and several hollow bolts are installed on the perforated insulating plate, and the hollow bolts drive the wire of the wire electrode to stretch, and each hollow The bolts correspond to one or two wire electrodes.

Figure 12 shows another embodiment of the stretcher. The tensioner includes a wire fixing frame 1201 , eight wire stretching bolts 1202 , eight wire fixing blocks 1203 and eight wire fixing bolts 1204 . In the wire fixing frame 1201, eight large threaded holes 1205 are provided on the frame. A wire tension bolt 1202 is installed in the threaded hole 1205 to provide a pulling force to the wire by rotating the tension bolt 1202 . The wire fixing block 1203 fixes the wire by the wire fixing bolt 1204 installed. Threaded holes 1206 are used to secure tension bolts 1202 to prevent movement after the wire is tensioned. The tensioner of this structure does not have high requirements on the size of the fixed frame, and the adjustment of the tension bolt is easier to operate.

The tension detection and adjustment of the wire electrodes in each chamber shall be performed, and the operation method shall refer to the adjustment method in the first embodiment.

Claims (9)

1. The utility model provides a wire electrode ion controlling means elongator which characterized in that: the device comprises at least two supporting cylinders, perforated insulating plates, wire electrodes, a wire stretcher and an ion detector, wherein two ends of each supporting cylinder are respectively in sealing fit with one perforated insulating plate to form a cavity, a group of wire electrodes are arranged in the cavity, a central hole is formed in the center of each perforated insulating plate, end electrodes are arranged on the perforated insulating plates, through holes are formed in the centers of the end electrodes, the positions of the through holes and the central hole are consistent, the supporting cylinders and the group of wire electrodes are arranged between every two adjacent perforated insulating plates, the number of each group of wire electrodes is at least 4, each wire electrode comprises at least 2 wires which are parallel to each other, surrounding holes are formed in the perforated insulating plates, and two ends of each wire respectively penetrate through and are fixed;

the perforated insulating plate is connected with a stretcher for adjusting the tension of the wire, the stretcher comprises a stretching bolt and a fixing bolt, the stretching bolt is connected with the wire, the tension of the wire changes along with the screwing of the stretching bolt, and the fixing bolt is used for clamping the stretching bolt after the tension is adjusted to fasten the position of the stretching bolt.

2. The wire electrode ion control device stretcher of claim 1, wherein: the stretching bolt is a hollow bolt, and the conducting wire penetrates through a through hole in the hollow bolt and is fixed on the stretching bolt.

3. The wire electrode ion control device stretcher of claim 2, wherein: the axis of the fixing bolt is perpendicular to the axis of the stretching bolt, and the fixing bolt props against the side face of the stretching bolt to fix the stretching bolt.

4. The wire electrode ion control device stretcher according to any one of claims 1 to 3, wherein: the stretcher further comprises a lead fixing frame, the lead fixing frame is fixedly connected with the perforated insulating plate, a threaded hole is formed in the lead fixing frame, and a stretching bolt is installed in the threaded hole.

5. The wire electrode ion control device stretcher of claim 4, wherein: the stretcher further comprises a fixing block and a bolt on the fixing block, the lead is clamped on the fixing block through the bolt, and the fixing block is sleeved on the stretching bolt.

6. The wire electrode ion control device stretcher of claim 4, wherein: the lead fixing frame is a circular or square frame, a through hole for communicating the inside and the outside is arranged on the frame, and the lead passes through the through hole.

7. The wire electrode ion control device stretcher of claim 5, wherein: the wire fixing frame is internally provided with a groove, and the fixing block is positioned in the groove.

8. The wire electrode ion control device stretcher of claim 1, wherein: each lead electrode is formed by the same metal wire passing through the corresponding surrounding hole back and forth, and the lead tension of each lead electrode is adjusted through a tension bolt.

9. A wire stretcher tension control method controlled by wire electrode ions is characterized by comprising the following steps: the device comprises at least three perforated insulating plates, wherein a center hole is formed in the center of each perforated insulating plate, a metal ring is arranged on the center hole, a supporting cylinder and a group of lead electrodes are arranged between every two adjacent perforated insulating plates, the number of each group of lead electrodes is at least 4, each lead electrode comprises at least 3 mutually parallel leads, a surrounding hole is formed in each perforated insulating plate, two ends of each lead respectively penetrate through and are fixed on the surrounding holes in the front perforated insulating plate and the rear perforated insulating plate, and the supporting cylinder surrounds the lead electrodes and is in sealing fit with the front perforated insulating plate and the rear perforated insulating plate to form a cavity; the perforated insulating plate is connected with a stretcher for adjusting the tension of the wire, the stretcher comprises a stretching bolt and a fixing bolt, the stretching bolt is connected with the wire, the tension of the wire changes along with the screwing of the stretching bolt, and the fixing bolt is used for clamping the stretching bolt after the tension is adjusted to fasten the position of the stretching bolt;

screwing a stretching bolt, applying tension to the wires, shifting each wire, measuring and recording the frequency of sound emitted by each wire by using a sound frequency testing instrument, adjusting the stretching bolt corresponding to the corresponding wire, loosening the wire with overhigh sound frequency, tensioning the wire with the sound frequency lower than the qualified range, continuously measuring the sound frequency until the sound frequency falls into the qualified range, and then fastening the corresponding stretching bolt by using a fixing bolt.

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