阅读说明：本技术 一种多粒子热阴极潘宁离子源及回旋加速器 (Multi-particle hot cathode penning ion source and cyclotron ) 是由 郑志鸿 姜冲 于 2021-07-13 设计创作，主要内容包括：本发明涉及粒子加速器领域,公开一种多粒子热阴极潘宁离子源及回旋加速器,离子源包括：电极杆,包括对称设置的电极杆阴极和电极杆对阴极；中心区弧室,包括对称且间隔设置的第一弧室和第二弧室,电极杆阴极的下端设有第一弧室,电极杆对阴极的上端设有第二弧室,第一弧室包括第一阳极壁和置于第一阳极壁中的第一阴极头,第二弧室包括第二阳极壁和置于第二阳极壁中的第二阴极头,第一阴极头和第二阴极头正对设置且分别连接静电高压电源,第一阳极壁和第二阳极壁正对设置且分别接地；多气源供气系统,与电极杆阴极和电极杆对阴极连接,多气源供气系统用于向中心区弧室通入气体。该多粒子热阴极潘宁离子源提高离子源的引出束流强度,且结构紧凑。(The invention relates to the field of particle accelerators, and discloses a multi-particle hot cathode penning ion source and a cyclotron, wherein the ion source comprises: the electrode rod comprises electrode rod cathodes and electrode rod counter cathodes which are symmetrically arranged; the central area arc chamber comprises a first arc chamber and a second arc chamber which are symmetrically arranged at intervals, the lower end of the cathode of the electrode rod is provided with the first arc chamber, the upper end of the counter cathode of the electrode rod is provided with the second arc chamber, the first arc chamber comprises a first anode wall and a first cathode head arranged in the first anode wall, the second arc chamber comprises a second anode wall and a second cathode head arranged in the second anode wall, the first cathode head and the second cathode head are arranged oppositely and are respectively connected with an electrostatic high-voltage power supply, and the first anode wall and the second anode wall are arranged oppositely and are respectively grounded; and the multi-gas-source gas supply system is connected with the cathode of the electrode rod and the counter cathode of the electrode rod and is used for introducing gas into the arc chamber in the central area. The multi-particle hot cathode penning ion source improves the intensity of the extracted beam current of the ion source and has a compact structure.)

1. A multi-particle hot cathode penning ion source comprising:

the electrode rod (1) comprises electrode rod cathodes (11) and electrode rod counter cathodes (12) which are symmetrically arranged;

the central area arc chamber (2) comprises a first arc chamber and a second arc chamber which are symmetrically arranged at intervals, the first arc chamber is arranged at the lower end of the electrode rod cathode (11), the second arc chamber is arranged at the upper end of the electrode rod counter cathode (12), the first arc chamber comprises a first anode wall (21) and a first cathode head (22) arranged in the first anode wall (21), the second arc chamber comprises a second anode wall (23) and a second cathode head (24) arranged in the second anode wall (23), the first cathode head (22) and the second cathode head (24) are arranged oppositely and are respectively connected with an electrostatic high-voltage power supply, and the first anode wall (21) and the second anode wall (23) are arranged oppositely and are respectively grounded;

and the multi-gas-source gas supply system (3) is connected with the electrode rod cathode (11) and the electrode rod counter cathode (12), and the multi-gas-source gas supply system (3) is used for introducing gas into the central area arc chamber (2).

2. The multi-particle hot cathode penning ion source of claim 1,

the first arc chamber further comprises a first heating unit (25), the first heating unit (25) is used for heating the first cathode head (22) to a preset temperature;

the second arc chamber further comprises a second heating unit (26), and the second heating unit (26) is used for heating the second cathode head (24) to a preset temperature.

3. The multi-particle hot cathode penning ion source of claim 1,

the first arc chamber further comprises a first cathode sleeve (27), the first cathode sleeve (27) is positioned inside the first anode wall (21), the first cathode sleeve (27) is used for supporting and sleeving the first cathode head (22), and the first cathode head (22) is arranged to protrude out of the first cathode sleeve (27);

the second arc chamber further comprises a second cathode sleeve (28), the second cathode sleeve (28) is located inside the second anode wall (23), the second cathode sleeve (28) is used for supporting and sleeving the second cathode head (24), and the second cathode head (24) protrudes out of the second cathode sleeve (28).

4. The multi-particle hot cathode penning ion source of claim 2,

electrode pole negative pole (11) with the structure of electrode pole anticathode (12) is the same, all includes first layer (111), second floor (112), third layer (113), fourth layer (114), fifth layer (115), sixth layer (116) and seventh layer (117) that from inside to outside overlaps in proper order and establish, ion source negative pole is connected to first layer (111), second layer (112) are the insulating layer, third layer (113) are connected the positive pole of first heating element (25) power, fourth layer (114) are the insulating layer, fifth layer (115) ground connection, the negative pole of first heating element (25) power with fifth layer (115) are connected, sixth layer (116) are connected many air supply gas supply system (3), seventh layer (117) ground connection, the ion source positive pole with seventh layer (117) are connected.

5. The multi-particle hot cathode penning ion source according to claim 4, wherein the multi-gas source gas supply system (3) comprises:

the gas cylinders are connected with the electrode rod cathode (11) and the electrode rod counter-cathode (12) through gas circuit branches.

6. The multi-particle hot cathode penning ion source of claim 5, further comprising:

the air path control system comprises control software, and an air inlet adjusting valve (41), an electromagnetic valve, a mass flow meter (42) and a high-pressure air meter (43) which are arranged in the air path branch, wherein the electromagnetic valve, the mass flow meter (42) and the high-pressure air meter (43) are respectively electrically connected with the control software.

7. The multi-particle hot cathode penning ion source of claim 6,

the air inlet regulating valve (41) is a manual valve.

8. The multi-particle hot cathode penning ion source of claim 6, wherein the gas path control system further comprises:

and the low-pressure gas meter (44) and the pressure reducing valve (45) are arranged in the gas path branch.

9. The multi-particle hot cathode penning ion source of claim 2, wherein the predetermined temperature is in the range of 300 ℃ to 400 ℃.

10. A cyclotron comprising a multi-particle hot cathode penning ion source according to any of claims 1 to 9.

Technical Field

The invention relates to the technical field of particle accelerators, in particular to a multi-particle hot cathode penning ion source and a cyclotron.

Background

The ion source is used for generating plasma, then is extracted and then is accelerated by a particle accelerator, and is one of important components of the accelerator. Ion source bagIncluding a penning ion source and an ECR ion source, which can be subdivided into a cold cathode penning ion source and a hot cathode penning ion source. The penning ion source is formed by an electric field formed by an anode and a cathode and used for generating electrons oscillating back and forth, and a magnetic field for restraining plasma is also required. The plasma generation principle of the penning ion source is as follows: taking proton penning ion source as an example, the cathode of the ion source emits electrons, the electrons oscillate back and forth in the electric field generated by the anode and the cathode, and high-purity hydrogen H is generated at the moment₂Injected into the ion source, electrons and hydrogen H₂Collide and move H₂Ionized into protons H +, so that H + generated near the region of potential 0 inside the ion source can be confined by the magnetic field to form a H + plasma. Different gases are injected into the ion source to correspondingly generate plasmas with different particles.

The existing penning ion source mainly has the technical problem of low intensity of the extracted beam current of the ion source. Therefore, the ion source can be installed in the center of the accelerator, but the magnetic field strength at the position is as high as 8.5T, which causes the cyclotron radius of the plasma after extraction to be very small, so the cathode structure of the ion source needs to be designed to be very compact, and how to optimize the structure under such conditions is a major difficulty at present.

Disclosure of Invention

The first purpose of the invention is to provide a multi-particle hot cathode penning ion source which improves the extraction beam intensity of the ion source and has a compact structure.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a multi-particle hot cathode penning ion source comprising:

the electrode rod comprises electrode rod cathodes and electrode rod counter cathodes which are symmetrically arranged;

the central area arc chamber comprises a first arc chamber and a second arc chamber which are symmetrically arranged at intervals, the first arc chamber is arranged at the lower end of the cathode of the electrode rod, the second arc chamber is arranged at the upper end of the counter cathode of the electrode rod, the first arc chamber comprises a first anode wall and a first cathode head arranged in the first anode wall, the second arc chamber comprises a second anode wall and a second cathode head arranged in the second anode wall, the first cathode head and the second cathode head are arranged oppositely and are respectively connected with an electrostatic high-voltage power supply, and the first anode wall and the second anode wall are arranged oppositely and are respectively grounded;

and the multi-gas-source gas supply system is connected with the cathode of the electrode rod and the counter cathode of the electrode rod and is used for introducing gas into the central area arc chamber.

As a preferred technical solution of the above multi-particle hot cathode penning ion source, the first arc chamber further includes a first heating unit, and the first heating unit is configured to heat the first cathode head to a preset temperature;

the second arc chamber further comprises a second heating unit, and the second heating unit is used for heating the second cathode head to a preset temperature.

As a preferred technical solution of the multi-particle hot cathode penning ion source, the first arc chamber further includes a first cathode sleeve, the first cathode sleeve is located inside the first anode wall, the first cathode sleeve is used for supporting and embedding the first cathode head, and the first cathode head protrudes out of the first cathode sleeve;

the second arc chamber further comprises a second cathode sleeve, the second cathode sleeve is located inside the second anode wall and used for supporting and embedding the second cathode head, and the second cathode head protrudes out of the second cathode sleeve.

As the preferred technical scheme of above-mentioned many particle hot cathode penning ion sources, the electrode pole negative pole with the structure of electrode pole anticathode is the same, all includes first layer, second floor, third layer, fourth layer, fifth layer, sixth layer and the seventh layer of establishing from inside to outside cover in proper order, the ion source negative pole is connected to the first layer, the second floor is the insulating layer, the third layer is connected the positive pole of first heating unit power, the fourth layer is the insulating layer, fifth layer ground connection, the negative pole of first heating unit power with the fifth layer is connected, the sixth layer is connected many air supplies gas supply system, seventh layer ground connection, the ion source positive pole with the seventh layer is connected.

As a preferable technical solution of the multi-particle hot cathode penning ion source, the multi-gas source gas supply system comprises:

and the gas cylinders are connected with the cathode of the electrode rod and the counter cathode of the electrode rod through gas circuit branches.

The preferable technical scheme of the multi-particle hot cathode penning ion source further comprises the following steps:

the gas circuit control system comprises control software, and an air inlet regulating valve, an electromagnetic valve, a mass flow meter and a high-pressure gas meter which are arranged in the gas circuit branch, wherein the electromagnetic valve, the mass flow meter and the high-pressure gas meter are respectively and electrically connected with the control software.

As a preferable technical scheme of the multi-particle hot cathode penning ion source, the air inlet adjusting valve is a manual valve.

As a preferred technical solution of the above multi-particle hot cathode penning ion source, the gas path control system further includes:

and the low-pressure gas meter and the pressure reducing valve are arranged in the gas circuit branch.

As a preferable technical scheme of the multi-particle hot cathode penning ion source, the preset temperature is 300-400 ℃.

A second object of the present invention is to provide a cyclotron whose ion source can extract a plurality of kinds of particles.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a cyclotron comprising a multi-particle hot cathode penning ion source according to any preceding claim.

The invention has the beneficial effects that:

the invention provides a multi-particle hot cathode penning ion source which comprises electrode rods, a central area arc chamber and a multi-gas source gas supply system, wherein the electrode rods comprise electrode rod cathodes and electrode rod counter cathodes which are symmetrically arranged; the central arc chamber comprises a first arc chamber and a second arc chamber which are symmetrically arranged at intervals, the lower end of the cathode of the electrode rod is provided with the first arc chamber, the upper end of the counter cathode of the electrode rod is provided with the second arc chamber, the first arc chamber comprises a first anode wall and a first cathode head arranged in the first anode wall, the second arc chamber comprises a second anode wall and a second cathode head arranged in the second anode wall, the first cathode head and the second cathode head are arranged oppositely and are respectively connected with an electrostatic high-voltage power supply, and the first anode wall and the second anode wall are arranged oppositely and are respectively grounded; and the multi-gas-source gas supply system is connected with the cathode of the electrode rod and the counter cathode of the electrode rod and is used for introducing gas into the arc chamber of the central area.

Under the structure, free electrons can reciprocate between the first cathode head and the second cathode head by the electrostatic high-voltage field formed between the first cathode head and the first anode wall and between the second cathode head and the second anode wall, the potential of the middle point of the connecting line of the first cathode head and the second cathode head is 0, the gas is ionized into protons after being impacted by the free electrons moving at high speed after entering the central area arc chamber, and is restrained near the area with the potential of 0 by the magnetic field to form plasma, and finally, the formed plasma is led out under the action of high-frequency accelerating voltage, so that the formed plasma starts to be accelerated continuously. The intensity of the extracted beam current of the hot cathode penning ion source is higher than that of the existing cold cathode penning ion source, and the dosage rate of particle treatment equipment can be improved, so that the clinical effect of FLASH treatment is further improved; and the structure is compact, and the device is suitable for being used in a subminiature superconducting synchrocyclotron.

The invention provides a cyclotron which comprises the multi-particle hot cathode penning ion source. The ion source of the cyclotron can extract various particles, can be applied to a multi-particle cyclotron, and is beneficial to researching the clinical effect of multi-particle radiotherapy.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the contents of the embodiments of the present invention and the drawings without creative efforts.

FIG. 1 is a schematic diagram of a multi-particle hot cathode penning ion source according to an embodiment of the present invention;

FIG. 2 is a partial cross-sectional view of a multi-particle hot cathode penning ion source provided in accordance with an embodiment of the present invention;

FIG. 3 is a partial cross-sectional view of an electrode rod of a multi-particle hot cathode penning ion source according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a multi-gas source gas supply system for a multi-particle hot cathode penning ion source according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a gas path control system of a multi-particle hot cathode penning ion source according to an embodiment of the present invention;

figure 6 is a partial cross-sectional view of a cyclotron as provided in an embodiment of the present invention;

fig. 7 is an external view of a cyclotron provided in accordance with an embodiment of the present invention.

In the figure:

1. an electrode rod;

11. an electrode rod cathode; 12. an electrode rod counter cathode; 111. a first layer; 112. a second layer; 113. a third layer; 114. a fourth layer; 115. a fifth layer; 116. a sixth layer; 117. a seventh layer;

2. a central zone arc chamber;

21. a first anode wall; 22. a first cathode head; 23. a second anode wall; 24. a second cathode head; 25. a first heating unit; 26. a second heating unit; 27. a first cathode sleeve; 28. a second cathode sleeve;

3. a multi-gas source gas supply system;

31. a first gas cylinder; 32. a second gas cylinder; 33. a third gas cylinder;

41. an air inlet regulating valve; 42. a mass flow meter; 43. a high pressure gas meter; 44. a low pressure gas meter; 45. a pressure reducing valve; 46. a first solenoid valve; 47. a second solenoid valve; 48. a third electromagnetic valve;

5. a computer;

6. a network switch;

100. a multi-particle hot cathode penning ion source; 200. a cyclotron.

Detailed Description

In order to make the technical problems solved, technical solutions adopted and technical effects achieved by the present invention clearer, the technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The technical solution of the multi-particle hot cathode penning ion source 100 provided by the present invention is further illustrated by the following specific embodiments in combination with the accompanying drawings.

The present embodiment provides a multi-particle hot cathode penning ion source 100, as shown in fig. 1 and fig. 2, the multi-particle hot cathode penning ion source 100 includes an electrode rod 1, a central region arc chamber 2, and a multi-gas source gas supply system 3, the electrode rod 1 includes an electrode rod cathode 11 and an electrode rod counter-cathode 12 which are symmetrically arranged; the central arc chamber 2 comprises a first arc chamber and a second arc chamber which are symmetrically arranged at intervals, the lower end of the cathode 11 of the electrode rod is provided with the first arc chamber, the upper end of the counter cathode 12 of the electrode rod is provided with the second arc chamber, the first arc chamber comprises a first anode wall 21 and a first cathode head 22 arranged in the first anode wall 21, the second arc chamber comprises a second anode wall 23 and a second cathode head 24 arranged in the second anode wall 23, the first cathode head 22 and the second cathode head 24 are arranged oppositely and are respectively connected with an electrostatic high-voltage power supply, the potential is-2 kV, the first anode wall 21 and the second anode wall 23 are arranged oppositely and are respectively grounded, and the potential is 0; the multi-gas-source gas supply system 3 is respectively connected with one end of the electrode rod cathode 11, which is far away from the first arc chamber, and one end of the electrode rod counter-cathode 12, which is far away from the second arc chamber, and the multi-gas-source gas supply system 3 is used for introducing gas into the central arc chamber 2.

Under the above structure, the electrostatic high voltage field formed between the first cathode head 22 and the first anode wall 21 and the electrostatic high voltage field formed between the second cathode head 24 and the second anode wall 23 can make the free electrons move back and forth between the first cathode head 22 and the second cathode head 24, the potential of the middle point of the connecting line of the first cathode head 22 and the second cathode head 24 is 0, the gas is ionized into protons after being impacted by the free electrons moving at high speed after entering the central region arc chamber 2, and is bound by the magnetic field to form plasma in the vicinity of the region with the potential of 0, and finally, the formed plasma is extracted under the action of the high-frequency accelerating voltage, so as to start to be continuously accelerated. The intensity of the extracted beam current of the hot cathode penning ion source is higher than that of the existing cold cathode penning ion source, and the dosage rate of particle treatment equipment can be improved, so that the clinical effect of FLASH treatment is further improved; and has a compact structure, and is suitable for use in the subminiature superconducting synchrocyclotron 200.

Further, the first arc chamber further comprises a first heating unit 25, and the first heating unit 25 is used for heating the first cathode head 22 to a preset temperature; the second arc chamber further comprises a second heating unit 26, the second heating unit 26 being adapted to heat the second cathode head 24 to a preset temperature. The cathode head after temperature rise can generate a large amount of free electrons under the action of an electrostatic high-voltage field.

Optionally, the preset temperature is 300 ℃ to 400 ℃. The specific temperature can be set according to actual conditions.

Preferably, the first heating unit 25 and the second heating unit 26 use filaments, and the filaments heat the cathode head to 300 ℃ -400 ℃ through a direct current power supply. The filament is readily available and inexpensive.

Further preferably, the first arc chamber further comprises a first cathode sleeve 27, the first cathode sleeve 27 is located inside the first anode wall 21, the first cathode sleeve 27 is used for supporting and sleeving the first cathode head 22, and the first cathode head 22 is arranged to protrude from the first cathode sleeve 27; the second arc chamber further comprises a second cathode sleeve 28, the second cathode sleeve 28 being located inside the second anode wall 23, the second cathode sleeve 28 being adapted to support the second cathode stub 24, and the second cathode stub 24 being arranged to protrude beyond the second cathode sleeve 28. Through setting up the negative pole sleeve, improved the structural strength and the stability of negative pole head. Optionally, the first cathode sleeve 27 and the second cathode sleeve 28 are made of high temperature resistant insulating material, ensuring the working stability.

Optionally, the end of the anode wall is V-shaped to facilitate the collection and guiding of free electrons emitted by the cathode head. Namely: the end part of the first anode wall 21 close to the second anode wall 23 is in a positive V shape, the end part of the second anode wall 23 close to the first anode wall 21 is in an inverted V shape, and the opening of the first anode wall 21 is opposite to the opening of the second anode wall 23.

In the present embodiment, the electrode rod cathode 11 and the electrode rod counter cathode 12 have the same structure, and the electrode rod cathode 11 is taken as an example in the present embodiment.

As shown in fig. 3, the electrode rod cathode 11 includes a first layer 111, a second layer 112, a third layer 113, a fourth layer 114, a fifth layer 115, a sixth layer 116, and a seventh layer 117, which are sequentially sleeved from inside to outside, the first layer 111 is connected to the ion source cathode, for example, a cathode bias voltage of-2 kV, the second layer 112 is an insulating layer, the third layer 113 is connected to the anode of the power supply of the first heating unit 25, the fourth layer 114 is an insulating layer, the fifth layer 115 is grounded, the potential is 0, the cathode of the power supply of the first heating unit 25 is connected to the fifth layer 115, the sixth layer 116 is an air inlet channel, which is connected to the multi-air-source air supply system 3 for introducing air, the seventh layer 117 is grounded, the potential is 0, and the ion source anode is connected to the seventh layer 117. The electrode rod cathode 11 and the electrode rod counter-cathode 12 are both composed of the seven-layer structure, so that the structural compactness of the penning ion source is improved, and the technical scheme of the hot cathode penning ion source is realized.

The existing penning ion source also has the technical problem that various particles cannot be extracted, so that the existing penning ion source cannot be applied to the multi-particle cyclotron 200. In order to realize multi-particle extraction ion sources, the gas circuit and the control module need to be optimally designed, so that the function of remotely controlling and switching different gases can be realized, and the requirement of high-purity indexes after gas switching is also required to be ensured.

Therefore, the multi-gas-source gas supply system 3 comprises at least two gas cylinders, and the gas cylinders are connected with the electrode rod cathode 11 and the electrode rod counter-cathode 12 through gas path branches. As shown in fig. 4 and fig. 5, in the present embodiment, three gases are taken as an example for explanation, that is, the multi-gas-source gas supply system 3 includes three gas cylinders, different gases, such as hydrogen gas, helium gas, neon gas, and the like, are stored in the three gas cylinders, and each gas cylinder is respectively connected to the electrode rod cathode 11 and the electrode rod anticathode 12 through a gas path branch. At the ends of the electrode rod cathode 11 and the electrode rod counter-cathode 12, the fifth layer 115 of the electrode rod 1 is connected with the ground wire a, and the seventh layer 117 is connected with the ground wire b, so that no electric field is generated in the air inlet channel of the sixth layer 116, and the electrode rod 1 is prevented from being damaged due to gas ionization and ignition.

Further, the multi-particle hot cathode penning ion source 100 further comprises an air path control system, as shown in fig. 5, the air path control system comprises control software and an air inlet regulating valve 41, an electromagnetic valve, a mass flow meter 42 and a high pressure gas meter 43 which are arranged in the air path branch, and the electromagnetic valve, the mass flow meter 42 and the high pressure gas meter 43 are respectively electrically connected with the control software. Alternatively, the intake air adjusting valve 41 is a manual valve.

The control software is installed in the terminals such as the computer 5, and the electromagnetic valve, the mass flow meter 42 and the high-pressure gas meter 43 are connected with the computer 5 through the network exchanger 6, so that the control software can control the electromagnetic valve, the mass flow meter 42 and the high-pressure gas meter 43.

Preferably, the air path control system further comprises a low pressure air meter 44 and a pressure reducing valve 45, which are both arranged in the air path branch.

It should be noted that the air intake regulating valve 41, the electromagnetic valve, the mass flow meter 42, the high pressure gas meter 43, the low pressure gas meter 44 and the pressure reducing valve 45 in this embodiment are all components that can be directly obtained in the prior art, and therefore, the structure and the operation principle thereof are not described again.

As shown in fig. 5, the gas entering the central arc chamber 2 can be selected by the control software through a first solenoid valve 46, a second solenoid valve 47 and a third solenoid valve 48. For example, when the first solenoid valve 46 is opened and the second solenoid valve 47 and the third solenoid valve 48 are closed, the multi-source gas supply system 3 selects gas from the first gas cylinder 31. The air intake rate can likewise be achieved on the computer 5 by controlling the mass flow meter 42 via the control software. The gas balance in each cylinder can be judged on the computer 5 by reading the high pressure gauge. The low pressure gauge is used in cooperation with the manual adjustment of the pressure reducing valve 45.

It is understood that the multi-particle hot cathode penning ion source 100 of the present embodiment further comprises a power supply system including an electrostatic high voltage power supply and a filament dc power supply, and a power supply of the gas path control system.

The working principle of the multi-particle hot cathode penning ion source 100 is illustrated below.

It is assumed that the gas in the first gas cylinder 31 is hydrogen, the gas in the second gas cylinder 32 is helium, and the gas in the third gas cylinder 33 is neon. When the first electromagnetic valve 46 is opened and the second electromagnetic valve 47 and the third electromagnetic valve 48 are closed, the hydrogen gas enters the sixth layer 116 of the electrode rod 1, namely the gas inlet channel, from the first gas bottle 31 through the gas path branch and then enters the central region arc chamber 2, and the flow control of the hydrogen gas is realized through the mass flow meter 42 remotely controlled by the computer 5. In the central arc chamber 2, the cathode head is heated to about 300-400 ℃ under the action of the filament, an electrostatic high-voltage field is generated between the cathode head and the anode wall, the cathode head generates a large amount of free electrons under the action of the filament and the electrostatic high-voltage field, the free electrons can reciprocate between the two cathode heads through the electrostatic field formed by the two cathode heads and the two anode walls, and meanwhile, the main magnet of the cyclotron 200 can form an axial magnetic field, the direction of the magnetic field is parallel to the electrode rod 1, and the magnetic field has a binding effect on the free electrons and plasma. After entering the central arc chamber 2, the hydrogen is ionized to form protons after being impacted by free electrons moving at high speed, and is bound by a magnetic field and stabilized between two cathode heads (near the middle point of 0 potential) to form plasma. Finally, the plasma is extracted by the high-frequency accelerating voltage, and thus starts to be continuously accelerated.

If the particle type is switched to helium ions, the second solenoid valve 47 can be opened, the first solenoid valve 46 and the third solenoid valve 48 are closed, and helium gas enters the sixth layer 116 of the electrode rod 1, namely the gas inlet channel, from the second gas cylinder 32 through the gas path branch and then enters the central region arc chamber 2, and helium ions are generated under the action of an electric field, a magnetic field and free electrons.

If the particle type is switched to neon ions, the third solenoid valve 48 is opened, the first solenoid valve 46 and the second solenoid valve 47 are closed, and neon gas enters the sixth layer 116 of the electrode rod 1, namely the gas inlet channel, from the third gas cylinder 33 through the gas path branch and then enters the central arc chamber 2, and neon ions are generated under the action of an electric field, a magnetic field and free electrons.

A second object of the present invention is to provide a cyclotron 200, the ion source of which can extract a plurality of kinds of particles. As shown in fig. 6 and 7, the cyclotron 200 includes the multi-particle hot cathode penning ion source 100 according to any of the above embodiments. The electrode rod cathode 11 and the electrode rod counter cathode 12 of the electrode rod 1 are inserted into the central region in the axial direction from above and below the cyclotron 200, respectively. Since the cyclotron 200 includes the multi-particle hot cathode penning ion source 100, it can be applied to the multi-particle cyclotron 200, and is helpful for studying the clinical effect of multi-particle radiotherapy.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Numerous obvious variations, adaptations and substitutions will occur to those skilled in the art without departing from the scope of the invention. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

It is noted that reference throughout this specification to "some embodiments," "other embodiments," or the like, means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.