A compact accelerator ultra-high vacuum system and a method for implementing the same

Abstract

This invention discloses a compact accelerator ultra-high vacuum system and its implementation method, comprising a diode iron vacuum chamber, a BUMP iron vacuum chamber, a BPM cavity, a vacuum pump chamber, and a quadrupole iron vacuum chamber connected sequentially to form a beam mainline. Multiple non-evaporable getter plates are arrayed within both the diode and quadrupole iron vacuum chambers to remove reactive gases from the beam mainline to achieve ultra-high vacuum. The vacuum pump chamber is equipped with a vacuum gauge, a sputtering ion pump, a molecular pump, and a gate valve. The vacuum gauge measures the vacuum level within the beam mainline, the sputtering ion pump removes argon and methane from the beam mainline and performs baking, the molecular pump performs rough evacuation of the beam mainline and exhausts gas during the baking process, and the gate valve isolates the molecular pump from the beam mainline. This invention can replace the method used when space constraints prevent the installation of a titanium sublimation pump to extract reactive gases such as hydrogen and carbon monoxide from the system, thereby achieving ultra-high vacuum.

Description

Technical Field

[0001] This invention belongs to the field of particle accelerator technology, and more particularly, it relates to a compact accelerator ultra-high vacuum system and its implementation method. Background Technology

[0002] With the continuous development of accelerator technology, heavy ion accelerators are moving towards higher energies and higher current intensities, and their application fields are constantly expanding. For example, the emergence of new applications such as medical heavy ion accelerators has provided important support for scientific research and economic and social development. The construction of the next-generation high-intensity heavy ion accelerator (HIAF) is basically completed, capable of providing pulsed heavy ion beams up to 4.25 GeV / u. To ensure the successful realization of this performance target, HIAF has placed higher requirements on the design of each system. Among them, the vacuum system, as a key component, requires the vacuum level of its enhancement ring (BRing) and high-precision ring spectrometer (SRing) to be better than 1×10⁻⁶. -9 Pa. To achieve this vacuum level requirement, BRIing and SRing used an ultra-high vacuum sputtering ion pump as the holding pump to extract gases such as argon and methane, while using a titanium sublimation pump as the main pump to extract reactive gases such as hydrogen and carbon monoxide.

[0003] However, the traditional ultra-high vacuum acquisition scheme combining ultra-high sputtering ion pumps and titanium sublimation pumps requires ample installation space. For some miniaturized accelerators, such as miniaturized medical heavy ion accelerators and miniature proton accelerators, the synchrotron ring itself has a limited length and consists of multiple dipole magnets, quadrupole magnets, hexapole magnets, correction magnets, BUMP magnets, high-frequency cavities, and BPMs, etc., and the locations of these components generally do not allow for the installation of a vacuum pump. Titanium sublimation pumps utilize the sublimation of titanium filaments to obtain a fresh titanium film on the pump body's surface, thereby achieving the pumping purpose. Its pumping speed depends on the size of the pump body's surface area, therefore, titanium sublimation pumps are often relatively large. If an NEG pump is used instead of a titanium sublimation pump, the pumping speed is easily limited by conductance because the vacuum chamber constituting the magnetic components has a relatively small height dimension. Therefore, for compact accelerator vacuum systems, to obtain a vacuum better than 1×10⁻⁶, a vacuum is required. -9 For vacuum levels of Pa, the methods of using titanium sublimation pumps or NEG pumps to extract reactive gases are no longer applicable.

[0004] In addition, there are internationally recognized methods for depositing getter films on the inner surface of the diode and quadrupole vacuum chambers. However, these films have a limited lifespan, lasting only about 10 uses, and require periodic removal of the pipes for recoating, which significantly increases the workload of the accelerator vacuum system. Summary of the Invention

[0005] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention provides a compact accelerator ultra-high vacuum system and its implementation method, aiming to achieve ultra-high vacuum performance in a compact accelerator.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a compact accelerator ultra-high vacuum system, comprising a dipole iron vacuum chamber, a BUMP iron vacuum chamber, a BPM cavity, a vacuum pump chamber, and a quadrupole iron vacuum chamber connected in sequence to form a beam mainline;

[0008] The two-pole iron vacuum chamber and the four-pole iron vacuum chamber are respectively installed inside the two-pole magnet and the four-pole magnet, and multiple non-evaporable getter sheets are arranged in an array in both the two-pole iron vacuum chamber and the four-pole iron vacuum chamber. The non-evaporable getter sheets are used to remove active gases in the main beam to obtain an extremely high vacuum.

[0009] The vacuum pump chamber is equipped with a vacuum measuring gauge, a sputtering ion pump, a molecular pump, and a gate valve. The vacuum measuring gauge is used to measure the vacuum level in the main beam. The sputtering ion pump is used to evacuate argon and methane from the main beam and bake it. The molecular pump is used for rough evacuation of the main beam and for exhausting gas during the baking process. The gate valve is used to isolate the molecular pump from the main beam so that the molecular pump does not affect the achievement of ultra-high vacuum.

[0010] Preferably, the polaritrile vacuum chamber includes a first vacuum flange, a first hydraulic bellows, a lower half of the polaritrile vacuum chamber, an upper half of the polaritrile vacuum chamber, a second hydraulic bellows, and a second vacuum flange. The lower half and the upper half of the polaritrile vacuum chamber are both arc-shaped and together form a polaritrile vacuum cavity. A plurality of non-evaporable getter tablets are periodically arranged on the planar areas of the upper part of the lower half and the lower part of the upper half of the polaritrile vacuum chamber. The first vacuum flange is connected to the first end of the polaritrile vacuum cavity through the first hydraulic bellows, and the second vacuum flange is connected to the second end of the polaritrile vacuum cavity through the second hydraulic bellows.

[0011] Preferably, the quadrupole vacuum chamber includes a third vacuum flange, a lower half of the quadrupole vacuum chamber, an upper half of the quadrupole vacuum chamber, a third hydraulic bellows, and a fourth vacuum flange. The lower half and the upper half of the quadrupole vacuum chamber are both linear and together form a quadrupole vacuum cavity. A plurality of non-evaporable getter sheets are periodically arranged on the planar areas of the upper part of the lower half and the lower part of the upper half of the quadrupole vacuum chamber. The third vacuum flange is connected to the first end of the quadrupole vacuum cavity, and the fourth vacuum flange is connected to the second end of the quadrupole vacuum cavity through the third hydraulic bellows.

[0012] Preferably, multiple columns with slots are periodically arranged on the planar areas of the lower half of the diode vacuum chamber, the upper half of the diode vacuum chamber, the lower half of the quadrupole vacuum chamber, and the upper half of the quadrupole vacuum chamber, and one of the non-evaporable getter tablets is fixed to one of the columns by a C-type buckle.

[0013] Preferably, the non-evaporable getter tablets are sintered from Ti-Zr-V-Al, with a diameter of 40 mm and a thickness of 2 mm. The pumping speed of a single tablet is about 86 L / s, and a total of 120 tablets are arranged in the diode vacuum chamber and a total of 68 tablets are arranged in the quadrupole vacuum chamber.

[0014] Preferably, an angle valve is also installed on the vacuum pump chamber, which is used to purge the vacuum pump chamber with nitrogen or inert gas.

[0015] In a second aspect, the present invention provides a method of using the compact ultra-high vacuum system as described in the first aspect of the present invention, comprising the following steps:

[0016] The molecular pump is activated to perform a rough pumping of the main beam to reduce the pressure inside the main beam to the first set pressure.

[0017] The sputtering ion pump is activated to remove water vapor from its inner surface, while the beam main line is heated to a first set temperature and maintained for a first set time by an external heat source.

[0018] Continue to heat the diode and quadrupole vacuum chambers to the second set temperature and maintain it for the second set time using an external heat source to activate the non-evaporable getter tablets and give them sufficient pumping speed for the active gas; at the same time, turn on the pumping function of the sputtering ion pump to remove argon and methane from the main beam.

[0019] The baking function of the sputtering ion pump is turned off to cool the main beam to the third set temperature. When the vacuum measuring gauge shows the second set pressure, the gate valve and molecular pump are turned off. After standing for the third set time, an extremely high vacuum can be obtained.

[0020] Preferably, the first set pressure is 5 × 10⁻⁶. -5 Below Pa, the second set pressure is 5 × 10⁻⁶. -8 Approximately Pa.

[0021] Preferably, the first set temperature is 250℃ and the first set time is 36h; the second set temperature is 300℃ and the second set time is 12h; the third set temperature is 150℃ and the third set time is 24h.

[0022] Preferably, the heating rate of the main beam is 0.5℃ / min, and the cooling rate of the main beam is 0.5℃ / min.

[0023] The present invention has the following advantages due to the adoption of the above technical solutions:

[0024] 1. This invention, within a limited space, such as a dipole vacuum chamber or a quadrupole vacuum chamber, arranges non-evaporable getter sheets to replace titanium sublimation pumps when space constraints prevent the installation of such pumps, thereby achieving extremely high vacuum (vacuum degree better than 1×10⁻⁶). -9 (Pa), and the distributed arrangement of non-evaporative getter tablets can achieve a more uniform pressure distribution.

[0025] 2. This invention combines the degassing and activation process of non-evaporable getter tablets with the vacuum baking process using an ultra-high sputtering ion pump. This eliminates the need for a separate power supply to degas and sublimate the titanium wire during the baking process when using a titanium sublimation pump as the main pump, making the vacuum process more convenient.

[0026] 3. In the vacuum baking process of this invention, a stepped temperature increase is adopted, which involves holding at 250℃ for 36 hours and at 300℃ for 12 hours. Under the conditions of repeatedly removing moisture from the vacuum system, degassing the non-evaporable getter tablets, and activating them, the service life of the non-evaporable getter tablets can be greatly increased. Attached Figure Description

[0027] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings:

[0028] Figure 1 This is a schematic diagram of the overall structure of the compact ultra-high vacuum system provided in Embodiment 1 of the present invention;

[0029] Figure 2This is a schematic diagram of the structure of the polar iron vacuum chamber provided in Embodiment 1 of the present invention;

[0030] Figure 3 This is a schematic diagram of the installation of the non-evaporable getter tablet provided in Embodiment 1 of the present invention;

[0031] Figure 4 This is a schematic diagram of the structure of the four-pole iron vacuum chamber provided in Embodiment 1 of the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments of the present invention will be further described below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0033] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0035] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0036] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0037] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0038] The compact accelerator ultra-high vacuum system provided by this invention includes a diode iron vacuum chamber, a BUMP iron vacuum chamber, a BPM chamber, a vacuum pump chamber, and a quadrupole iron vacuum chamber connected sequentially to form a beam mainline. Multiple non-evaporable getter plates are arrayed within both the diode and quadrupole iron vacuum chambers to remove reactive gases from the beam mainline to achieve ultra-high vacuum. The vacuum pump chamber is equipped with a vacuum gauge, a sputtering ion pump, a molecular pump, and a gate valve. The vacuum gauge measures the vacuum level within the beam mainline, the sputtering ion pump removes argon and methane from the beam mainline and preheats it, the molecular pump performs rough evacuation of the beam mainline and exhausts gas during the preheating process, and the gate valve isolates the molecular pump from the beam mainline. This invention can replace the method used when space constraints prevent the installation of a titanium sublimation pump to extract reactive gases such as hydrogen and carbon monoxide from the system, thereby achieving ultra-high vacuum.

[0039] The compact accelerator ultra-high vacuum system and its implementation method provided by the present invention will now be described in detail with reference to the accompanying drawings.

[0040] Example 1:

[0041] Please see Figure 1The compact ultra-high vacuum system provided in this embodiment includes a diode iron vacuum chamber 1, a BUMP iron vacuum chamber 2 (for beam delivery), a BPM cavity 3 (for beam position and status monitoring), a vacuum pump chamber 4, and a quadrupole iron vacuum chamber 5, which are connected in sequence to form the main beam line. The diode iron vacuum chamber 1 and the quadrupole iron vacuum chamber 5 are respectively installed inside a diode magnet and a quadrupole magnet, and both the diode iron vacuum chamber 1 and the quadrupole iron vacuum chamber 5 have multiple non-evaporable getter sheets 6 arranged in an array. The non-evaporable getter sheets 6 are used to remove reactive gases (such as hydrogen, carbon monoxide, etc.) from the main beam line to form an ultra-high vacuum.

[0042] Vacuum pump chamber 4 is equipped with vacuum measuring gauge tube 7, sputtering ion pump 8, molecular pump 9 and gate valve 10. Vacuum measuring gauge tube 7 is used to measure the vacuum level in the main beam. Sputtering ion pump 8 is used to remove argon and methane from the main beam and bake it. Molecular pump 9 is used for rough evacuation of the main beam and exhaust during the baking process. Gate valve 10 is used to isolate molecular pump 9 from the main beam so that molecular pump 9 does not affect the realization of ultra-high vacuum.

[0043] In the above embodiments, preferably, the polariton vacuum chamber 1 includes a first vacuum flange 11, a first hydraulic bellows 12, a lower half 13 of the polariton vacuum chamber, an upper half 14 of the polariton vacuum chamber, a second hydraulic bellows 15, and a second vacuum flange 16. The lower half 13 and the upper half 14 of the polariton vacuum chamber are both arc-shaped and together form a polariton vacuum cavity. Multiple non-evaporable getter sheets 6 are periodically arranged on the planar areas of the upper part of the lower half 13 and the lower part of the upper half 14 of the polariton vacuum chamber. The first vacuum flange 11 is connected to the first end of the polariton vacuum cavity through the first hydraulic bellows 12, and the second vacuum flange 16 is connected to the second end of the polariton vacuum cavity through the second hydraulic bellows 15.

[0044] In the above embodiments, preferably, the quadrupole vacuum chamber 5 includes a third vacuum flange 51, a lower half of the quadrupole vacuum chamber 52, an upper half of the quadrupole vacuum chamber 53, a third hydraulic bellows 54, and a fourth vacuum flange 55. The lower half of the quadrupole vacuum chamber 52 and the upper half of the quadrupole vacuum chamber 53 are both linear and together form a quadrupole vacuum cavity. Multiple non-evaporable getter sheets 6 are periodically arranged on the planar areas above the lower half of the quadrupole vacuum chamber 52 and below the upper half of the quadrupole vacuum chamber 53. The third vacuum flange 51 is connected to the first end of the quadrupole vacuum cavity, and the fourth vacuum flange 55 is connected to the second end of the quadrupole vacuum cavity through the third hydraulic bellows 54.

[0045] In the above embodiments, preferably, multiple columns 20 with slots are periodically arranged on the planar areas of the lower half 13 of the diode vacuum chamber, the upper half 14 of the diode vacuum chamber, the lower half 52 of the quadrupole vacuum chamber, and the upper half 53 of the quadrupole vacuum chamber. A non-evaporable getter tablet 6 is fixed to a column 20 by a C-type buckle 21. This can avoid damage to its structure caused by sudden vacuum breakage and factors such as transportation and installation, without affecting its pumping performance.

[0046] In the above embodiments, preferably, the non-evaporable getter tablet 6 is sintered from Ti-Zr-V-Al, with a diameter of 40 mm and a thickness of 2 mm. The pumping speed of a single tablet is about 86 L / s, and a total of 120 tablets are arranged in the dipolar iron vacuum chamber 1 and a total of 68 tablets are arranged in the quadrupole iron vacuum chamber 5.

[0047] In the above embodiments, preferably, an angle valve 22 is also installed on the vacuum pump chamber 4, which is used to fill the vacuum pump chamber 4 with nitrogen or inert gas to ventilate it.

[0048] Example 2:

[0049] Based on the compact accelerator ultra-high vacuum system in Embodiment 1, this embodiment also provides a method for implementing the compact accelerator ultra-high vacuum system, including the following steps:

[0050] S100. Start molecular pump 9 to perform rough pumping on the main beam, reducing the pressure inside the main beam to 5 × 10⁻⁶. -5 Below Pa;

[0051] S200. Activate the baking function of sputtering ion pump 8 to remove water vapor from its inner surface, and at the same time, use an external heat source (such as a heating jacket or heating belt) to heat the main beam to 250°C at a heating rate of 0.5°C / min and continue for 36 hours.

[0052] S300. Continue to heat the polariton vacuum chamber 1 and the quadrupole vacuum chamber 5 to 300°C and maintain this temperature for 12 hours using an external heat source to activate the non-evaporable getter 6 and give it sufficient pumping speed for the active gas; at the same time, turn on the pumping function of the sputtering ion pump 8 to remove argon and methane from the main beam.

[0053] S400. Turn off the baking function of sputtering ion pump 8, and cool the main beam to 150°C at a cooling rate of 0.5°C / min. Wait until the vacuum measuring gauge 7 displays 5×10⁻⁶. -8 When the pressure is around 8 Pa, close the gate valve 10 and the molecular pump 9. After standing for 24 hours, the vacuum measuring gauge 7 shows 8 × 10⁻⁸. -10 Pa, better than the design target of 1×10 -9Pa demonstrates the feasibility of integrating non-evaporable getter sheets 6 inside the diode magnet vacuum chamber 1 and the quadrupole magnet vacuum chamber 5 to remove active gases, and using an ultra-high sputtering ion pump 8 as a means to maintain the ultra-high vacuum of the pump.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A compact accelerator ultra-high vacuum system, characterized in that, It includes a dipole iron vacuum chamber, a BUMP iron vacuum chamber, a BPM cavity, a vacuum pump chamber, and a quadrupole iron vacuum chamber connected in sequence to form the main beam line; The two-pole iron vacuum chamber and the four-pole iron vacuum chamber are respectively installed inside the two-pole magnet and the four-pole magnet, and multiple non-evaporable getter sheets are arranged in an array in both the two-pole iron vacuum chamber and the four-pole iron vacuum chamber. The non-evaporable getter sheets are used to remove active gases in the main beam to obtain an extremely high vacuum. The vacuum pump chamber is equipped with a vacuum measuring gauge, a sputtering ion pump, a molecular pump, and a gate valve. The vacuum measuring gauge is used to measure the vacuum level in the main beam. The sputtering ion pump is used to evacuate argon and methane from the main beam and bake it. The molecular pump is used for rough evacuation of the main beam and for exhausting gas during the baking process. The gate valve is used to isolate the molecular pump from the main beam so that the molecular pump does not affect the achievement of ultra-high vacuum.

2. The compact accelerator ultra-high vacuum system according to claim 1, characterized in that, The diode vacuum chamber includes a first vacuum flange, a first hydraulic bellows, a lower half of the diode vacuum chamber, an upper half of the diode vacuum chamber, a second hydraulic bellows, and a second vacuum flange. The lower half and the upper half of the diode vacuum chamber are both arc-shaped and together form a diode vacuum cavity. A plurality of non-evaporable getter tablets are periodically arranged on the planar areas of the upper part of the lower half and the lower part of the upper half of the diode vacuum chamber. The first vacuum flange is connected to the first end of the diode vacuum cavity through the first hydraulic bellows, and the second vacuum flange is connected to the second end of the diode vacuum cavity through the second hydraulic bellows.

3. The compact accelerator ultra-high vacuum system according to claim 2, characterized in that, The quadrupole vacuum chamber includes a third vacuum flange, a lower half of the quadrupole vacuum chamber, an upper half of the quadrupole vacuum chamber, a third hydraulic bellows, and a fourth vacuum flange. The lower half and the upper half of the quadrupole vacuum chamber are both linear and together form a quadrupole vacuum cavity. A plurality of non-evaporable getter tablets are periodically arranged on the planar areas of the upper part of the lower half and the lower part of the upper half of the quadrupole vacuum chamber. The third vacuum flange is connected to the first end of the quadrupole vacuum cavity, and the fourth vacuum flange is connected to the second end of the quadrupole vacuum cavity through the third hydraulic bellows.

4. The compact accelerator ultra-high vacuum system according to claim 3, characterized in that, Multiple columns with slots are periodically arranged on the planar areas of the lower half of the diode vacuum chamber, the upper half of the diode vacuum chamber, the lower half of the quadrupole vacuum chamber, and the upper half of the quadrupole vacuum chamber. One of the non-evaporable getter tablets is fixed to one of the columns by a C-type buckle.

5. The compact accelerator ultra-high vacuum system according to claim 4, characterized in that, The non-evaporable getter tablets are sintered from Ti-Zr-V-Al, with a diameter of 40 mm and a thickness of 2 mm. The pumping speed of a single tablet is about 86 L / s. A total of 120 tablets are arranged in the diode vacuum chamber and 68 tablets are arranged in the quadrupole vacuum chamber.

6. The compact accelerator ultra-high vacuum system according to any one of claims 1 to 5, characterized in that, An angle valve is also installed on the vacuum pump chamber, which is used to purge the vacuum pump chamber with nitrogen or inert gas.

7. A method for implementing a compact accelerator ultra-high vacuum system as described in any one of claims 1 to 6, characterized in that, Includes the following steps: The molecular pump is activated to perform a rough pumping of the main beam to reduce the pressure inside the main beam to the first set pressure. The sputtering ion pump is activated to remove water vapor from its inner surface, while the beam main line is heated to a first set temperature and maintained for a first set time by an external heat source. Continue to heat the diode and quadrupole vacuum chambers to the second set temperature and maintain it for the second set time using an external heat source to activate the non-evaporable getter tablets and give them sufficient pumping speed for the active gas; at the same time, turn on the pumping function of the sputtering ion pump to remove argon and methane from the main beam. The baking function of the sputtering ion pump is turned off to cool the main beam to the third set temperature. When the vacuum measuring gauge shows the second set pressure, the gate valve and molecular pump are turned off. After standing for the third set time, an extremely high vacuum can be obtained.

8. The implementation method according to claim 7, characterized in that, The first set pressure is 5×10 -5 Below Pa, the second set pressure is 5 × 10⁻⁶. -8 Pa.

9. The implementation method according to claim 7, characterized in that, The first set temperature is 250℃ and the first set time is 36h; the second set temperature is 300℃ and the second set time is 12h; the third set temperature is 150℃ and the third set time is 24h.

10. The implementation method according to claim 7, characterized in that, The heating rate of the main beam is 0.5℃ / min, and the cooling rate of the main beam is 0.5℃ / min.

Images