CN114709129A - A mass analyzer system and mass spectrometer - Google Patents

Abstract

The invention discloses a mass analyzer system, which comprises an ion lens group, an analysis electromagnet and a detector, wherein the ion lens group, the analysis electromagnet and the detector adopt an asymmetric structure, the distance between the ion lens group and the analysis electromagnet is smaller than the distance between the analysis electromagnet and the detector, the deflection radius of the magnetic field center of the analysis electromagnet is 200-220mm, and the incident angle of ions output by the ion lens group entering the analysis electromagnet is smaller than the exit angle of the ions output by the analysis electromagnet. The invention also discloses a mass spectrometer. The invention has the advantages of compact layout, small occupied space, light weight and the like.

Description

A mass analyzer system and mass spectrometer

technical field

The invention belongs to the technical field of analysis, and in particular relates to a mass analyzer system and a mass spectrometer including the mass analyzer system.

Background technique

Thermal ionization mass spectrometry (TIMS) is an analytical testing technology developed in the 1970s to accurately measure element isotopic abundance and isotope abundance ratio. Compared with other analytical techniques, thermal ionization mass spectrometry has the advantages of high accuracy and high precision. , Thermal ionization mass spectrometer has been widely used in nuclear industry, environment, geology, archaeology and other fields.

The mass analyzer system is the place where ions with different mass-to-charge ratios are mass-separated, and is an important part of the thermal ionization mass spectrometer, which directly determines the sensitivity, mass resolution, mass dispersion, aberration and other parameters of the thermal ionization mass spectrometer. Practical analytical level of thermal ionization mass spectrometry.

At present, there are three major manufacturers of thermal ionization mass spectrometers in the world: ThermoFisher, Ametek, and Isotopx. The mass analyzer system has its own unique ion optical design. Although all of them can achieve the purpose of mass spectrometry, they have the problems of large footprint and heavy weight, which are not conducive to layout. In addition, these thermal ionization mass spectrometers still have the disadvantages of high energy consumption and low resolution.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a mass analyzer system and a mass spectrometer with the advantages of compact layout and small footprint, aiming at the above shortcomings of the prior art.

The technical scheme that the present invention solves the above-mentioned technical problems is:

According to one aspect of the present invention, a mass analyzer system is provided, which includes an ion lens group, an analysis electromagnet, and a detector, wherein the ion lens group, the analysis electromagnet, and the detector adopt an asymmetric structure , the distance between the ion lens group and the analysis electromagnet is smaller than the distance between the analysis electromagnet and the detector, and the deflection radius of the magnetic field center of the analysis electromagnet is 200-220mm, and the ions output by the ion lens group enter the incidence of the analysis electromagnet The angle is smaller than the exit angle of the ions output by the analysis electromagnet.

Preferably, the distance between the ion lens group and the analysis electromagnet is 450-480mm, the distance between the analysis electromagnet and the detector is 570-600mm, and the incident angle of the analysis electromagnet is 27- 30°, the exit angle of the analyzing electromagnet is 29-32°.

Preferably, the ion lens group includes an accelerating pole lens, an extracting pole lens, a focusing lens, a focusing pole X lens, a focusing pole Z lens, an ion source exit slit, an output lens, and a high-voltage power supply connector. The lens, the extraction pole lens, the focusing lens, the focusing pole X lens, the focusing pole Z lens, the ion source exit slit, and the output lens are arranged in sequence, and the output lens is located close to the The position of the analysis electromagnet; the high-voltage power connector, the accelerating pole lens, the extraction pole lens, the focusing lens, the focusing pole X lens, the focusing pole Z lens, and the output lens are respectively electrically connected for supplying voltage.

Preferably, the voltage of the high-voltage power connector is below 10KV, and the width of the ion source outlet slit is 0.2 mm.

Preferably, the high-voltage power supply connector includes a plurality of power supply modules, which are respectively a first module, a second module, a third module, a fourth module, a fifth module, and a sixth module, wherein:

The first module is electrically connected to the accelerator lens, and the voltage range for providing the accelerator lens is 9900±100V;

The second module is electrically connected to the lead-out lens, and the voltage range provided to the lead-out lens is 8600±300V;

The third module is electrically connected to the focusing lens, and the voltage range for providing the focusing lens is 9000±100V;

The fourth module is electrically connected to the focusing pole X lens, and the voltage range for providing the focusing pole X lens is 5000±100V;

The fifth module is electrically connected to the focusing pole Z lens, and the voltage range provided to the focusing pole Z lens is 450±250V;

The sixth module is electrically connected to the output lens, and is used for providing the output lens with a voltage range of 1500±250V.

Preferably, the analyzing electromagnet includes a magnetic yoke, a pole piece, a magnetic pole coil, and a magnetic induction stabilizing coil, the pole piece is arranged in the magnetic yoke, and the magnetic pole coil and the magnetic induction stabilizing coil are sleeved on the magnetic induction stabilizing coil. on the pole piece, and the magnetic induction stabilizing coil is located at one end of the gap close to the pole piece, the magnetic pole coil is used to generate a magnetic field, and the magnetic induction stabilizing coil is used to compensate the magnetic field generated by the magnetic pole coil.

Preferably, the gap of the pole piece is 12-15mm, and both the magnetic pole coil and the magnetic induction stabilization coil are wound with low-resistance enameled wires with a current density of less than 2A/mm ² .

Preferably, the number of Faraday cups in the detector is more than eight, and the Faraday cups are arranged in a row in sequence to form a focus plane, wherein the position of the Faraday cup in the most middle position is fixed, and the rest of the Faraday cups are in a fixed position. The position of the cup can be moved in the direction of the focal plane.

Preferably, the included angle between the focusing plane and the main optical axis of ion transmission of the analyzing electromagnet is 20-30°, and the width of the receiving slit of the Faraday cup is 0.8-1.0 mm.

Preferably, the system further includes a second focusing lens and a zoom lens, the second focusing lens is arranged between the ion lens group and the analyzing electromagnet, and is used for optimizing the focusing of the ion beam output by the ion lens group Effect; the zoom lens is arranged between the analyzing electromagnet and the detector for improving the dispersion distance.

According to another aspect of the present invention, there is also provided a mass spectrometer comprising the mass analyzer system described above.

The mass analyzer system and mass spectrometer of the present invention can reduce the center orbit radius of the analyzing electromagnet, the distance between the ion lens group and the analyzing electromagnet, and the distance between the analyzing electromagnet and the detector by adopting the asymmetric ion optical design. Spacing and other related parameters make the structure layout of the whole system compact, which can effectively reduce the overall size and weight of the system. In addition, by improving the structural composition and parameters of the ion lens group, the analysis electromagnet, and the detector, not only the resolution (greater than 500), the ion transmission efficiency (above 90%) and other properties can be improved, but the mass number range of 3- 280amu full mass isotope analysis can also reduce power consumption and achieve environmental protection and energy saving; by setting the second focusing lens, the ions can be further focused in the X and Y directions before they enter the analysis electromagnet, and by setting the zoom The lens can further adjust the mass dispersion distance of the ions separated by the analytical electromagnet, thereby improving the receiving efficiency of the detector.

Description of drawings

1 is a schematic structural diagram of a mass analyzer system in an embodiment of the present invention;

2 is a schematic structural diagram of an ion lens group in an embodiment of the present invention;

3 is a schematic structural diagram of an output lens in an embodiment of the present invention;

Fig. 4 is the structural schematic diagram of analyzing electromagnet in the embodiment of the present invention;

Fig. 5 is the decomposition schematic diagram of analyzing electromagnet in the embodiment of the present invention;

6 is a schematic structural diagram of a detector in an embodiment of the present invention;

7 is a schematic structural diagram of another mass analyzer system in an embodiment of the present invention;

8 is a schematic structural diagram of a second focusing lens in an embodiment of the present invention;

9 is a cross-sectional view of a second focusing lens in an embodiment of the present invention.

In the figure: 1-ion lens group; 2-analysis electromagnet; 3-detector; 10-accelerating pole lens; 11-extracting pole lens; 12-focusing lens; 13-focusing pole X lens; 14-focusing pole Z lens ; 15- ion source exit slit; 16- output lens; 20- yoke; 21- pole piece; 22- magnetic induction stabilization coil; 23- pole coil; 24- moving device; 30- Faraday cup; 31- secondary electron 32-deflection electrode; 33-high voltage connector; 41-second pole; 161-first electrode; 162-second electrode; 163-third electrode; 164-fourth electrode.

Detailed ways

In order to make those skilled in the art better understand the technical solutions of the present invention, the technical solutions in the present invention will be described clearly and completely below with reference to the accompanying drawings. Obviously, the described embodiments are of the present invention. Some examples, but not all examples. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the indication of orientation or positional relationship such as "up" is based on the orientation or positional relationship shown in the drawings, which is only for convenience and simplification of the description, and does not indicate or imply that The device or element must be provided with a specific orientation, constructed and operated in a specific orientation, so it should not be construed as a limitation of the present invention.

In the description of the present invention, the terms "first" and "second" are only used for the purpose of description, and cannot be understood as indicating or implying relative importance or implying the number of indicated technical features. Thus, features defined as "first", "second" may expressly or implicitly include one or more of said features. In the description of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

In the description of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "connection", "arrangement", "installation", "fixation", etc. should be understood in a broad sense, for example, it may be a fixed connection or a It is a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of the two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

Example 1

As shown in FIG. 1 , this embodiment discloses a mass analyzer system, which can be used for thermal ionization mass spectrometer (TIMS), multi-receiver inductively coupled plasma mass spectrometer (MC-ICP-MS), etc., which includes an ion lens group 1, The analysis electromagnet 2 and the detector 3, wherein the ion lens group 1, the analysis electromagnet 2, and the detector 3 adopt an asymmetric structure, and the distance between the ion lens group 1 and the analysis electromagnet 2 is smaller than that between the analysis electromagnet 2 and the analysis electromagnet 2. The distance between the detectors 3 and the center deflection radius of the magnetic field of the analyzing electromagnet 2 is 200-220 mm, and the incident angle of the ions output by the ion lens group 1 entering the analyzing electromagnet is smaller than the exit angle of the ions output by the analyzing electromagnet.

Specifically, the ion lens group 1 is used to adjust and focus the ions, the analysis electromagnet 2 is used to provide a stable and adjustable magnetic field, and the detector 3 is used to measure the ion beam current intensity. The distance between the ion lens group 1 and the analysis electromagnet 2 is in the range of 450-480 mm, and the distance between the analysis electromagnet 2 and the detector 3 is in the range of 570-600 mm. The incident angle range of the ions output by the ion lens group 1 entering the analyzing electromagnet is 27-30°, and the exit angle range of the ions output by the analyzing electromagnet is 29-32°.

The principle of the mass analyzer system is as follows: using a uniform magnetic field to separate the mass-to-charge ratio m/e according to the size of the Lorentz force of ions of different masses entering the analysis electromagnet;

According to the acceleration equation of the ion in the electric field and the Lorentz force equation in the magnetic field:

Then the ion mass-to-charge ratio is:

Among them, q represents the number of charges of the ion, U ₀ represents the accelerating voltage, m represents the mass of the ion, B represents the strength of the magnetic field, V represents the velocity of the ion, and r _m represents the deflection radius of the center of the magnetic field;

When the accelerating voltage U ₀ and the magnetic field strength B are adjusted to appropriate values, ions with different mass-to-charge ratios (m/q) achieve different deflection radii, and then reach different Faraday cups, and the ion beam current intensity is measured by the detector.

In this embodiment, the distance between the ion lens group 1 and the analysis electromagnet 2 is preferably 430mm, the distance between the analysis electromagnet 2 and the detector 3 is preferably 580mm, and the incident angle of the ion analysis electromagnet output by the ion lens group It is preferably 28°, and the exit angle of the ions output by the analyzing electromagnet is preferably 30°.

Compared with the prior art, an output lens 16 is added to the ion lens group 1 in this embodiment, that is to say, as shown in FIG. 2 , the ion lens group 1 includes an accelerating pole lens 10 , an extraction pole lens 11 , and a focusing lens 12. Focusing pole X lens 13, focusing pole Z lens 14, ion source exit slit 15, output lens 16, and high-voltage power supply connector, wherein: accelerating pole lens 10, extracting pole lens 11, focusing lens 12, focusing pole X The lens 13, the focusing electrode Z lens 14, the ion source exit slit 15, and the output lens 16 are arranged in parallel in sequence, and the output lens 16 is in a position close to the analyzing electromagnet 2; The lens 11 , the focusing lens 12 , the focusing pole X lens 13 , the focusing pole Z lens 14 , and the output lens 16 are respectively electrically connected for supplying voltages to the aforementioned lenses.

Specifically, the width of the ion source outlet slit 15 may be 0.2-0.3 mm, preferably 0.2 mm, and the distance between the ion source outlet slit 15 and the analyzing electromagnet 2 may be 420-440 mm, preferably 430 mm. The output lens 16 is connected to the ion source exit slit 15 through stainless steel support rods, positioning ceramics, fastening bolts and other components. The output lens can be adjusted and corrected before the ion beam enters the magnetic field in the analysis electromagnet to improve the ion transmission efficiency. (more than 90 percent).

The voltage range that the high-voltage power supply connector can provide is preferably 0-10KV, that is, the voltage of the high-voltage power supply connector is below 10KV, or the maximum voltage of the high-voltage power supply connector is 10KV, and the maximum ion acceleration of the ion lens group is The voltage is 10KV, which can be adjusted according to actual needs.

In this embodiment, the high-voltage power connector includes a plurality of modules, which are a first module, a second module, a third module, a fourth module, a fifth module, and a sixth module (not shown in the figure), wherein: The first module is electrically connected with the accelerating pole lens 10, and the voltage range for supplying the accelerating pole lens is 9900±100V, and the preferred voltage is 9900V; The range of the provided voltage is 8600±300V, and the preferred voltage is 8600V; the third module is electrically connected to the focusing lens 12, and the range of the voltage used to provide the focusing lens is 9000±100V, and the preferred voltage is 9000V; the fourth The module is electrically connected to the focusing pole X lens 13, and the voltage range for supplying the focusing pole X lens is 5000±100V, and the preferred voltage is 5000V; the fifth module is electrically connected to the focusing pole Z lens 14, and is used to supply the focusing pole X lens 14 to the focusing pole. The voltage range provided by the Z lens is 450±250V, and the preferred voltage is 450V; the sixth module is electrically connected to the output lens 16, and the voltage range for providing the output lens is 1500±250V, and the preferred voltage is 1500V. By arranging a plurality of modules to respectively supply voltages to the accelerator lens 10 , the extractor lens 11 , the focusing lens 12 , the focusing electrode X lens 13 , the focusing electrode Z lens 14 , and the output lens 16 , it can be beneficial for the ion beam to obtain the best focusing and transfer effect.

In this embodiment, as shown in FIG. 3 , the output lens 16 includes four electrodes, which are a first electrode 161 , a second electrode 162 , a third electrode 163 , and a fourth electrode 164 , wherein the first electrode 161 and the The two electrodes 162 are one group, and the two are opposite to each other and are in the first direction. The voltage between the first electrode 161 and the second electrode 162 is preferably 0-190V; the third electrode 163 and the fourth electrode 164 are another group, The two are opposite to each other in the second direction, and the second direction is perpendicular to the first direction, and the voltage between the third electrode 163 and the fourth electrode 164 is preferably 0-190V.

Compared with the prior art, a magnetic induction stabilization coil 22 is added to the analyzing electromagnet 2 of this embodiment. As shown in FIGS. 4 and 5 , the electromagnet 2 analyzed in this embodiment includes a magnetic yoke 20 , a pole piece 21 , a magnetic pole coil 23 , a magnet power supply, and a magnetic induction stabilization coil 22 , wherein: the pole piece 21 is arranged in the magnetic yoke 20 , the magnetic pole coil 23 and the magnetic induction stabilizing coil 22 are sleeved on the pole piece 21, and the magnetic induction stabilizing coil 22 is at one end of the gap close to the pole piece, the magnetic pole coil 23 is used to generate a magnetic field; In the process of magnetic field regeneration adjustment, a small amount of compensation is performed to improve the stability of the magnetic field; the magnet power supply is respectively connected to the magnetic pole coil 23 to provide a stable and adjustable current for the magnetic pole coil.

Specifically, the magnetic field center deflection radius (also referred to as "central track radius") of the analytical electromagnet 2 can be 200-220 mm, preferably 200 mm. Compared with the prior art (above 260 mm), the magnetic field center deflection radius is significantly reduced. Small, which is beneficial to reduce the weight of the analysis electromagnet. The material of the yoke 20 and the pole piece 21 is preferably DT4 pure iron. The gap (ie, the air gap) of the pole pieces in the analytical electromagnet 2 may be 12-15 mm, preferably 14 mm. The incident angle of the ions output by the ion transmission electron microscope entering the analyzing electromagnet 2 is preferably 28°, and the exit angle of the ions output by the analyzing electromagnet 2 is preferably 30°. The exit surface pole in the analysis electromagnet 2 is designed with a circular arc surface, and the radius r of the circular arc surface can be 600-700 mm, preferably 665 mm, so as to improve the ion focusing effect.

Both the magnetic pole coil 23 and the magnetic induction stabilization coil 22 are preferably made of low-resistance enameled wire with a current density of less than 2A/mm ² , so as to reduce the heating of the windings. Compared with the prior art, it is not necessary to be equipped with a cooling water machine, thereby reducing the power consumption of the instrument. . The number of the magnetic pole coils 23 and the magnetic induction stabilization coils 22 is two, and the two coils are connected in parallel. The magnet power supply is designed with conventional standard components, the output current to the pole coil 23 is preferably 0.2-16A, and the uniformity of the magnetic field generated by the pole coil 23 is less than 50ppm.

Through the above settings, the magnification (M) of the analysis electromagnet 2 can reach 1.5, with high precision; the magnetic field intensity can be continuously and stably adjustable between 0-1.24T; the abundance and Accurate measurement of abundance ratios.

In addition, the bottom of the analyzing electromagnet can be provided with a moving device 24, which can be driven by the moving device to achieve the leveling of the analyzing electromagnet in the horizontal and vertical directions.

In this embodiment, the moving device 24 includes a horizontal adjustment unit and a vertical adjustment unit (not shown in the figure), wherein: the horizontal adjustment unit may include a horizontal guide rail, and the analyzing electromagnet is arranged on the horizontal guide rail and can slide along the horizontal guide rail, To adjust the position of the analysis electromagnet in the horizontal direction; the vertical adjustment unit can also adopt the same or similar structure as the horizontal adjustment unit, which will not be repeated here, to adjust the position of the analysis electromagnet in the horizontal direction.

Compared with the prior art, as shown in FIG. 6 , the detector in this embodiment also includes a Faraday cup 30 , a secondary electron multiplier 31 , a deflection electrode 32 , a high-voltage connector 33 , and a detector housing (not shown in the figure). The inner cavity of the detector shell is in a vacuum state, the Faraday cup 30, the secondary electron multiplier 31, the deflection electrode 32, and the high-voltage connector 33 are arranged in the detector shell, and the wiring method is the same as that of the existing The technology is the same and will not be repeated here. The difference is:

The gain multiplier of the secondary electron multiplier 21 is 10 ⁶ , and the high-resistance value of the amplifier of the Faraday cup 20 is 10 ¹¹ Ω, so that the vacuum cavity in the detector shell can be reduced as much as possible under the premise of ensuring the performance requirements. size (the diameter of the vacuum chamber can reach about 300mm), thereby reducing power consumption.

The number of the secondary electron multipliers 31 may be one or a plurality of them, and a commercially available Daly detector may be used. The number of the Faraday cups 30 is multiple, for example, more than 8, the Faraday cups 30 are arranged in a row in sequence, and the orientation of the receiving slits of each Faraday cup is the same to form a focusing plane, wherein the Faraday cups in the middle order The position of the cup 30 is fixed. Specifically, when the number of Faraday cups is odd, the position of the Faraday cup in the middle order is fixed, and when the number of Faraday cups 30 is even, the two in the middle order The position of any one of the Faraday cups 30 is fixed. For example, when the number of Faraday cups 30 is 8, the positions of the fourth and/or fifth Faraday cups are fixed, and the positions of the remaining Faraday cups 30 can be moved along the direction of the focus plane. , to adjust the position of each Faraday cup according to the different elements analyzed, thereby ensuring sensitivity and precision.

The structure of the Faraday cup 30 adopts a conventional structure, which is composed of a receiving slit, a suppression pole, an insulating block, and a casing, and the whole is in the shape of a rectangular box. One side of the Faraday cup is opened for receiving the ion beam, and the other sides are sealed .

In this embodiment, the width of the receiving slit of the Faraday cup 30 is preferably 0.8-1.0 mm; except for the middlemost position (for example, when the number of Faraday cups is eight, the middlemost position refers to the fourth Faraday cup and/or the third Faraday cup The moving range of the positions of the remaining Faraday cups 30 other than the five Faraday cups is preferably 0-44 mm; the size of the Faraday cup 30 is preferably 12×2×1 mm; the material of the Faraday cup 30 can be stainless steel, or Made of high-purity graphite, the adjustment accuracy of a single Faraday cup 30 can be 10 μm, and the adjustment method can be adjusted by a stepper motor or manually by a worm gear guide; The angle between the main optical axes of ion transport may be 20-30°, preferably 25°.

Through the above settings, when the high resistance of the amplifier of the Faraday cup 30 is 10 ¹¹ Ω, the Faraday cup 30 can detect the ion current with a current of 6.0×10 ⁻¹⁴ A-2.7×10 ⁻¹⁰ A, and the secondary electron multiplier 31 (SEM ) can detect ion currents down to 1.6×10 ^-18 A.

In the mass analyzer system of this embodiment, by adopting an asymmetric ion optics design, the center orbit radius of the analysis electromagnet, the distance between the ion lens group and the analysis electromagnet, the distance between the analysis electromagnet and the detector, etc. can be reduced. The relevant parameters make the structure and layout of the whole system compact, thereby effectively reducing the overall size and weight of the system. In addition, by improving the structural composition and parameters of the ion lens group, the analysis electromagnet, and the detector, not only the resolution (greater than 500), the ion transmission efficiency (above 90%) and other properties can be improved, but the mass number range of 3- 280amu full mass isotope analysis can also reduce power consumption and achieve environmental protection and energy saving.

Example 2

This embodiment discloses a mass analyzer system, which is different from Embodiment 1 in that, as shown in FIG. 7 , it further includes a second focusing lens 4 and a zoom lens 5 , wherein the second focusing lens 4 is arranged on the ion Between the lens group 1 and the analysis electromagnet 2, it is used to optimize the focusing effect of the ion beam output by the ion lens group, improve the flat top effect, and further improve the transmission efficiency; the zoom lens 5 is arranged between the analysis electromagnet 2 and the detector 3 , which is used to improve the dispersion distance to improve the nesting capability between multiple sets of ion beams and multiple Faraday cup receivers.

Specifically, the second focusing lens 4 is preferably arranged at a position closer to the entrance of the analysis electromagnet 2, and the zoom lens 5 is preferably arranged at a position closer to the exit of the analysis electromagnet 2. It should be noted that due to the second focusing The lens 4 and the zoom lens 5 only play the role of optimizing the focusing effect of the ion beam and improving the dispersion of the mass analyzer system, and will not affect the final focusing image point of the ion beam (that is, the Faraday cup receiving position). Therefore, the second focusing lens 4 The zoom lens 5 and the zoom lens 5 can also be arranged in other positions than the above-mentioned positions, which can be flexibly selected according to requirements.

As shown in FIG. 8 and FIG. 9 , the second focusing lens 4 adopts an electrostatic quadrupole lens, which includes four poles 41 , wherein the two poles 41 are arranged opposite to each other and are in the same direction (such as the horizontal direction, that is, the In the x-axis direction), the other two poles 41 are arranged opposite to each other, and in another direction (such as the vertical direction, that is, the y-axis direction), the center of the adjacent poles 41 is within the enclosed area of the four poles 41. The angle between the centers of the tangent circles is 90°. If the positive voltage is applied to the two poles 41 in the horizontal direction, the negative voltage of the same magnitude is applied to the two poles 41 in the vertical direction. On the contrary, if the two poles 1 in the horizontal direction apply a negative voltage, Then the two poles 41 in the vertical direction apply a positive voltage of the same magnitude, and the range of the applied voltage is preferably between 0±20V.

The zoom lens 5 can be any one of a quadruple, a hexadecimal, an 8th, and a twelfth, so as to fine-tune the mass dispersion of the ion beam within ±5%. The voltage application method of the zoom lens 5 is similar to that of the second focusing lens. Taking the lens of six-pole rods as an example, it includes six second poles, x terminals, and y terminals, and one end of each second pole is connected to x. The other end of each second pole is connected to the y terminal. If a positive voltage is applied to the six poles on the x terminal, the same magnitude of negative voltage is applied to the six poles on the y terminal, otherwise, If a negative voltage is applied to the six poles on the x terminal, a positive voltage of the same magnitude is applied to the six poles on the y terminal, preferably in the range of 0±50V.

More specifically, each pole in the second focusing lens 4 and the zoom lens 5 can be a circular pole, a semicircular pole, a hyperboloid pole, a rod pole, and a plane pole. any of the rods. In addition, if the pole is a cylindrical pole, the radius of the cylindrical pole shall be 1.1 to 1.2 times the radius of the inscribed circle enclosed by each pole, and the length of the pole shall not be less than 3 times the radius of the inscribed circle. ; If the pole is another type of pole, the radius and length of the pole can also be designed according to the same (cylindrical pole), which will not be repeated here.

The mass analyzer system of this embodiment has all the advantages of the mass analyzer system in Embodiment 1, and since the second focusing lens and the zoom lens are added, the second focusing lens can detect the ions before they enter the analyzing electromagnet. It performs further focusing in the X and Y directions, and the zoom lens can further adjust the mass dispersion distance of the ions separated by the mass of the analyzing electromagnet, thus ultimately improving the receiving efficiency of the detector.

Example 3

This embodiment discloses a mass spectrometer, which includes an ion source, a shielded glove box, and the mass analyzer system described in Embodiment 1.

Specifically, the mass spectrometer in this embodiment may be a thermal ionization mass spectrometer (TIMS) or a multi-receiver inductively coupled plasma mass spectrometer (MC-ICP-MS). The lens group 1 extracts, accelerates, focuses and reshapes and then arrives at the analyzing electromagnet 2. The ions of different masses are mass-separated in the fan-shaped magnetic field generated by the analyzing electromagnet 2, and finally the ions reach the detector 3 for ion beam intensity detection.

Among them, the ion lens group 1, the analysis electromagnet 2, the detector 3 in the mass analyzer system are preferably arranged in order from right to left, compared with the ion lens group 1, the analysis electromagnet 2, the detector 3 in the prior art The detectors 3 are all arranged from left to right. Since the ion source is opened on the right side, the sealing between the ion source and the shielding glove box can be facilitated.

The mass spectrometer of this embodiment adopts the mass analyzer system described in Embodiment 1, and has the following advantages: compact structure and small volume, the size of the whole machine can be reduced to 1750х1050х1600mm; light weight, the weight of the whole machine can be reduced to 1000Kg ; Low power consumption, the rated power of the whole machine can be reduced to 3.5kW, compared with the existing technology, the power is reduced by about half; high resolution, can reach more than 500; high ion transmission efficiency, can reach more than 90%; The multiple (M) can reach 1.5, which can realize the isotopic analysis of the mass number range of 3-280amu full mass number.

It can be understood that the above embodiments are only exemplary embodiments adopted to illustrate the principle of the present invention, but the present invention is not limited thereto. For those skilled in the art, without departing from the spirit and essence of the present invention, various modifications and improvements can be made, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims (11)

1. A mass analyzer system comprises an ion lens group (1), an analyzing electromagnet (2) and a detector (3), and is characterized in that the ion lens group, the analyzing electromagnet and the detector adopt asymmetric structures, the distance between the ion lens group and the analyzing electromagnet is smaller than the distance between the analyzing electromagnet and the detector, the deflection radius of the magnetic field center of the analyzing electromagnet is 200-220mm, and the incident angle of ions output by the ion lens group entering the analyzing electromagnet is smaller than the exit angle of the ions output by the analyzing electromagnet.

2. The mass analyzer system of claim 1, wherein the distance between the ion lens set and the analyzing electromagnet is 450-480mm, the distance between the analyzing electromagnet and the detector is 570-600mm, the incident angle of the analyzing electromagnet is 27-30 °, and the exit angle of the analyzing electromagnet is 29-32 °.

3. A mass analyser system according to claim 1 wherein the ion lens group comprises an accelerating pole lens (10), an extraction pole lens (11), a focusing lens (12), a focusing pole X lens (13), a focusing pole Z lens (14), an ion source exit slit (15), an output lens (16), and a high voltage power connector,

the accelerating pole lens, the extraction pole lens, the focusing pole X lens, the focusing pole Z lens, the ion source outlet slit and the output lens are sequentially arranged, and the output lens is positioned close to the analysis electromagnet;

the high voltage power connector is electrically connected with the accelerating electrode lens, the extraction electrode lens, the focusing electrode X lens, the focusing electrode Z lens and the output lens respectively for providing voltage.

4. A mass analyser system according to claim 3 wherein the high voltage power connector has a voltage of 10KV or less and the ion source exit slit has a width of 0.2 mm.

5. The mass analyzer system of claim 3, wherein the high voltage power connector comprises a plurality of power supply modules, a first module, a second module, a third module, a fourth module, a fifth module, and a sixth module,

the first module is electrically connected with the accelerator lens and is used for providing voltage to the accelerator lens in a range of 9900 +/-100V;

the second module is electrically connected with the extraction electrode lens and is used for providing voltage to the extraction electrode lens within a range of 8600 +/-300V;

the third module is electrically connected with the focusing lens and is used for providing voltage for the focusing lens in a 9000 +/-100V range;

the fourth module is electrically connected with the X lens of the focusing electrode and is used for providing voltage for the X lens of the focusing electrode within the range of 5000 +/-100V;

the fifth module is electrically connected with the focusing pole Z lens and is used for providing voltage for the focusing pole Z lens within a range of 450 +/-250V;

the sixth module is electrically connected with the output lens and used for providing the voltage range for the output lens to be 1500 +/-250V.

6. A mass analyser system according to claim 1 wherein the analysis electromagnet comprises a yoke (20), a pole piece (21), a pole coil (23), and a magnetic induction stabilizing coil (22),

the pole shoe is arranged in the magnetic yoke, the magnetic pole coil and the magnetic induction stabilizing coil are sleeved on the pole shoe, the magnetic induction stabilizing coil is located at one end close to a gap of the pole shoe, the magnetic pole coil is used for generating a magnetic field, and the magnetic induction stabilizing coil is used for compensating the magnetic field generated by the magnetic pole coil.

7. A mass analyser system according to claim 6 wherein the pole piece gap is 12-15mm, and the pole coil and the magnetic induction stabilisation coil each use a current density of less than 2A/mm²Winding the low-resistance enameled wire.

8. The mass analyzer system of claim 1, wherein the number of faraday cups (30) in the detector is eight or more, each faraday cup being sequentially aligned in a row to form a focal plane, wherein the position of the most intermediate faraday cup is fixed and the remaining faraday cups are movable in position along the focal plane.

9. The mass analyzer system of claim 8, wherein the angle between the focal plane and the principal axis of ion transmission of the analyzing electromagnet is 20-30 °, and the faraday cup has a receiving slit width of 0.8-1.0 mm.

10. A mass analyser system according to any one of claims 1-9 further comprising a second focusing lens (4) and a zoom lens (5),

the second focusing lens is arranged between the ion lens group and the analysis electromagnet and is used for optimizing the focusing effect of the ion beam output by the ion lens group;

the zoom lens is arranged between the analysis electromagnet and the detector and used for improving the dispersion distance.

11. A mass spectrometer comprising a mass analyser system as claimed in any one of claims 1 to 10.

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