Pinning ion source and method of operation thereof

Abstract

The application provides a Penning ion source which is composed of an ion source base and an ion generation cavity arranged on the ion source base, and the ion generation cavity comprises an ion source cathode, a hot-start electron emission source, an anode cylinder and an ion source counter-cathode; the ion source cathode is arranged at one end of the ion generation cavity and connected with the ion source base, the ion source counter-cathode is arranged at the other end of the ion generation cavity, the anode cylinder and the hot-start electron emission source are arranged between the ion source cathode and the ion source counter-cathode, the anode cylinder and the hot-start electron emission source are electrically connected with an external power supply, and the hot-start electron emission source emits hot electrons under current heating as starting electrons of each pulse of the Penning ion source. The application can solve the key problem of improving the pulse characteristics of a small-diameter pulse neutron tube based on the Penning ion source.

Description

Technical Field

[0001] This invention relates to the field of accelerator neutron source technology, and more particularly to a Penning ion source and its operating method. Background Technology

[0002] Neutron tubes, as small, controllable neutron sources, can operate in high-repetition-frequency pulsed states, using the pulse start moment as the timing zero point for back-end measurements, thus enabling the widespread application of pulsed neutrons. However, current small-diameter neutron tubes utilize cold cathode Penning ion sources. Because the initial electrons in the pulsed discharge mainly originate from field-induced electron emission at the cold cathode surface and a small number of ionized particles in the background gas caused by cosmic rays, the pulsed discharge of cold cathode Penning ion sources has a relatively long delay time and pulse rise time. Furthermore, the pulse discharge delay time and pulse rise time of cold cathode Penning ion sources increase with decreasing discharge current, making it impossible for them to cover a wider range of neutron yields with short delay and rise times. Therefore, improving the output neutron pulse characteristics over a wider neutron yield range without increasing the size of the Penning ion source and neutron tube has become a key issue in expanding the performance of neutron tube pulsed applications. Summary of the Invention

[0003] This invention provides a Penning ion source that includes a thermionic filament installed in the discharge space between the two cathodes of the Penning ion source. Thermionic emission from the thermionic filament, heated by current, serves as the starting electron for each pulse of the cold cathode pulsed Penning ion source, significantly reducing the pulse delay time, rise time, and timing jitter of the discharge current. Simultaneously, the thermionic filament is connected in series with a gas reservoir of a small-diameter neutron tube. The large current required for the gas reservoir's operation heats the thermionic filament, achieving electron emission from the thermionic cathode without additional neutron tube power. This significantly improves the pulse characteristics of the micro-pulse Penning ion source, solving the key problem of improving the pulse characteristics of small-diameter pulsed neutron tubes based on Penning ion sources.

[0004] This invention provides a Penning ion source, which consists of an ion source base and an ion generating cavity disposed on the ion source base. The ion generating cavity includes: an ion source cathode, a thermally activated electron emission source, an anode cylinder, and an ion source-to-cathode pair.

[0005] The ion source cathode is located at one end of the ion generation chamber and connected to the ion source base. The ion source cathode pair is located at the other end of the ion generation chamber. The anode cylinder and the thermally activated electron emission source are located between the ion source cathode and the ion source cathode pair. The anode cylinder and the thermally activated electron emission source are electrically connected to an external power source. The thermionic electrons emitted by the thermally activated electron emission source under current heating serve as the starting electrons for each pulse of the Penning ion source.

[0006] Optionally, the hot-start electron emission source includes a gas storage device and a hot cathode filament connected in series, and the gas storage device and the hot cathode filament form an electrical circuit with the external power source.

[0007] Optionally, the ion source base is provided with a first electrode hole, in which a filament feed electrode is installed. One end of the filament feed electrode is electrically connected to the external power supply, and the other end of the filament feed electrode is electrically connected to the gas storage device.

[0008] Optionally, the ion source base is provided with a second electrode hole, in which a support electrode rod is installed. One end of the support electrode rod is electrically connected to the external power source, and the other end of the support electrode rod is electrically connected to the anode cylinder.

[0009] Optionally, a first cathode limit groove is provided in the middle of the ion source base, the axis of the first cathode limit groove coincides with the ion source base, and the ion source cathode is disposed in the first cathode limit groove.

[0010] Optionally, the ion source cathode has a receiving tank, in which a magnet is disposed.

[0011] Optionally, the ion generating chamber further includes an ion source shell, wherein the outer peripheral opening of the ion source base is provided with a shell limiting groove, and one end of the ion source shell is fitted into the limiting groove of the ion source base.

[0012] Optionally, the ion generating chamber further includes a magnetic ring or magnetic cylinder and an ion source lead-out electrode. The other end of the ion source shell is provided with a second cathode limit groove. The ion source cathode, the magnetic ring or magnetic cylinder, and the ion source lead-out electrode are sequentially stacked and installed in the second cathode limit groove of the ion source shell.

[0013] Secondly, embodiments of the present invention also provide a method for operating a Penning ion source, wherein the method for operating a Penning ion source is applied to any of the Penning ion sources provided in the embodiments of the present invention, and the method for operating a Penning ion source includes the following steps:

[0014] After power-on, the thermionic electrons emitted by the thermally activated electron emission source under current heating are used as the activation electrons for each pulse of the Penning ion source.

[0015] Optionally, the hot-start electron emission source includes a gas storage device and a hot cathode filament connected in series, the gas storage device and the hot cathode filament forming an electrical circuit with the external power source, and the operation method of the Penning ion source includes the following steps:

[0016] After power-on, the thermionic electrons emitted by the hot cathode filament under current heating are used as the starting electrons for each pulse of the Penning ion source.

[0017] In this embodiment of the invention, the ion source cathode is disposed at one end of the ion generation cavity and connected to the ion source base, the ion source cathode pair is disposed at the other end of the ion generation cavity, the anode cylinder and the hot-start electron emission source are disposed between the ion source cathode and the ion source cathode pair, and the anode cylinder and the hot-start electron emission source are electrically connected to an external power source. The thermionic electrons emitted by the hot-start electron emission source under current heating serve as the starting electrons for each pulse of the Penning ion source. The thermionic electrons emitted by the hot cathode filament under current heating serve as the starting electrons for each pulse of the cold cathode pulse Penning ion source, thereby significantly shortening the pulse delay time, rise time and time jitter of the discharge current of the cold cathode pulse Penning ion source. At the same time, the hot cathode filament is connected in series with the gas storage device of the small-diameter neutron tube, and the large current required for the operation of the gas storage device is used to heat the hot cathode filament in series. Electron emission of the hot cathode is achieved without adding an additional neutron tube power supply. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a Penning ion source provided in an embodiment of the present invention;

[0020] Among them, 1. Ion source base, 2. Filament feed electrode, 3. Ion source cathode, 4. Gas storage, 5. Hot cathode filament, 6. Support electrode rod, 7. Anode cylinder, 8. Ion source shell, 9. Ion source cathode, 10. Magnetic ring or magnetic cylinder, 11. Ion source lead-out electrode, 12. Magnet. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] like Figure 1 As shown, Figure 1 This is a schematic diagram of a Penning ion source provided in an embodiment of the present invention. The Penning ion source consists of an ion source base 1 and an ion generating cavity disposed on the ion source base 1. The ion generating cavity includes: an ion source cathode 3, a thermally activated electron emission source, an anode cylinder 7, and an ion source cathode pair 9. The ion source cathode 3 is disposed at one end of the ion generating cavity and connected to the ion source base 1, the ion source cathode pair 9 is disposed at the other end of the ion generating cavity, the anode cylinder 7 and the thermally activated electron emission source are disposed between the ion source cathode 3 and the ion source cathode pair 9, and the anode cylinder 7 and the thermally activated electron emission source are electrically connected to an external power source. The thermionic electrons emitted by the thermally activated electron emission source under current heating serve as the starting electrons for each pulse of the Penning ion source.

[0023] In this embodiment of the invention, the Penning ion source described above can be a composite cold cathode pulsed Penning ion source that is activated by hot cathode electrons.

[0024] The aforementioned ion source base 1 is a support structure for the ion source, used to fix and support the various components of the ion source; the aforementioned ion generating chamber is the core working area of ​​the ion source, used to generate an ion beam.

[0025] In this embodiment of the invention, the thermionic electrons emitted by the thermally started electron emission source under current heating are used as the starting electrons for each pulse of the Penning ion source, thereby significantly shortening the pulse delay time, rise time and time jitter of the discharge current of the Penning ion source.

[0026] Optionally, the hot-start electron emission source includes a gas storage device 4 and a hot cathode filament 5 connected in series, and the gas storage device 4 and the hot cathode filament 5 form an electrical circuit with the external power source.

[0027] In this embodiment of the invention, the hot cathode filament 5 is connected in series with the gas storage device 4. The large current required for the operation of the gas storage device 4 is used to heat the hot cathode filament in series, thereby realizing electron emission of the hot cathode filament 5 without adding an extra neutron tube power supply.

[0028] The gas storage device 4, the hot cathode filament 5 and the external power source form an electrical circuit, indicating that the gas storage device 4 and the hot cathode filament 5 will be connected to the external power source through this electrical circuit to generate the required current.

[0029] Optionally, the ion source base 1 is provided with a first electrode hole, in which a filament feed electrode 2 is installed. One end of the filament feed electrode 2 is electrically connected to the external power supply, and the other end of the filament feed electrode 2 is electrically connected to the gas storage device 4.

[0030] In this embodiment of the invention, after the filament feed electrode 2 is installed on the ion source base 1 according to the first electrode hole position, it is fixed to the ion source base 1. The gas storage device 4 is fixedly connected to the filament feed electrode 2, one end of the filament feed electrode 2 is electrically connected to an external power source, and the other end of the filament feed electrode 2 is electrically connected to the gas storage device 4.

[0031] Optionally, the ion source base 1 is provided with a second electrode hole, in which a support electrode rod 6 is installed. One end of the support electrode rod 6 is electrically connected to the external power source, and the other end of the support electrode rod 6 is electrically connected to the anode cylinder 7.

[0032] In this embodiment of the invention, the second electrode hole is used to install the support electrode rod 6. After the support electrode rod 6 is installed on the ion source base 1 according to the position of the second electrode hole, it is welded and fixed on the ion source base 1.

[0033] The other end of the aforementioned support electrode rod 6 is electrically connected to the anode cylinder 7. Through this connection, the anode cylinder 7 can obtain electrical energy from the support electrode rod 6.

[0034] Optionally, a first cathode limit groove is provided in the middle of the ion source base 1, the axis of the first cathode limit groove coincides with the ion source base 1, and the ion source cathode 3 is disposed in the first cathode limit groove.

[0035] In this embodiment of the invention, the ion source cathode 3 is installed in the first cathode limit groove of the ion source base 1 and welded and fixed to the ion source base 1.

[0036] Specifically, the ion source base 1 has a first cathode limit groove in its middle section to accommodate the ion source cathode 3. The function of this first cathode limit groove is to ensure the positioning and stability of the ion source cathode 3 in the ion source. The fact that the ion source cathode 3 is located in the first cathode limit groove means that the ion source cathode 3 is located inside the limit groove, which can ensure the stable position of the ion source cathode 3 in the ion source, and also facilitates the installation and maintenance of the ion source cathode 3.

[0037] Optionally, the ion source cathode 3 has a receiving groove, and a magnet 12 is disposed in the receiving groove.

[0038] In this embodiment of the invention, the ion source cathode 3 has a receiving tank, and a magnet 12 is disposed in the receiving tank to provide the required magnetic field.

[0039] Optionally, the ion generating chamber further includes an ion source shell 8, and the outer peripheral opening of the ion source base 1 is provided with a shell limiting groove, and one end of the ion source shell 8 is fitted with the limiting groove of the ion source base 1.

[0040] In this embodiment of the invention, the ion source shell 8 is installed in the shell limiting groove of the ion source base 1 and spot-welded to the ion source base 1.

[0041] Specifically, the ion source housing 8 is the external protective cover of the ion source, used to fix and support the various components of the ion source. The ion source housing 8 and the ion source base 1 are installed together through the fit of the housing limiting groove to achieve stable positioning and support.

[0042] Optionally, the ion generating chamber further includes a magnetic ring or magnetic cylinder 10 and an ion source extraction electrode 11. The other end of the ion source housing 8 is provided with a second cathode limit groove. The ion source cathode 9, the magnetic ring or magnetic cylinder 10, and the ion source extraction electrode 11 are sequentially stacked and installed in the second cathode limit groove of the ion source housing 8.

[0043] In this embodiment of the invention, the ion source cathode 9, magnetic ring or magnetic cylinder 10, and ion source lead-out electrode 11 are sequentially stacked and installed in the second cathode limit slot of the ion source shell 8, and the ion source lead-out electrode 11 is spot welded to the ion source shell 8.

[0044] In this embodiment of the invention, the filament feed electrode 2 and the supporting electrode rod 6 are installed on the ion source base 1 according to the hole positions, and then welded and fixed to the ion source base 1. The ion source cathode 3 is then installed in the cathode limit groove of the ion source base 1 and welded and fixed to the ion source base 1. The gas reservoir 4 is fixedly connected to the filament feed electrode 2, and the hot cathode filament 5 is connected to the other electrode of the gas reservoir 4. The anode cylinder 7 is then inserted into the supporting electrode rod 6 and then spot-welded and fixed. The ion source housing 8 is then installed in the limit groove of the ion source base 1 and spot-welded and fixed to the ion source base 1. The ion source cathode 9, magnetic ring or magnetic cylinder 10, and ion source lead-out electrode 11 are then stacked and installed in sequence in the limit groove of the ion source housing 8, and the ion source lead-out electrode 11 is spot-welded and fixed to the ion source housing 8. Finally, the magnet 12 is inserted into the ion source cathode 3, completing the manufacturing of the composite cold cathode pulsed Penning ion source.

[0045] In this embodiment of the invention, the ion source cathode is disposed at one end of the ion generation cavity and connected to the ion source base, the ion source cathode pair is disposed at the other end of the ion generation cavity, the anode cylinder and the hot-start electron emission source are disposed between the ion source cathode and the ion source cathode pair, and the anode cylinder and the hot-start electron emission source are electrically connected to an external power source. The thermionic electrons emitted by the hot-start electron emission source under current heating serve as the starting electrons for each pulse of the Penning ion source. The thermionic electrons emitted by the hot cathode filament under current heating serve as the starting electrons for each pulse of the cold cathode pulse Penning ion source, thereby significantly shortening the pulse delay time, rise time and time jitter of the discharge current of the cold cathode pulse Penning ion source. At the same time, the hot cathode filament is connected in series with the gas storage device of the small-diameter neutron tube, and the large current required for the operation of the gas storage device is used to heat the hot cathode filament in series. Electron emission of the hot cathode is achieved without adding an additional neutron tube power supply.

[0046] Secondly, embodiments of the present invention also provide a method for operating a Penning ion source. This method is applied to any of the Penning ion sources described in the embodiments of the present invention. (Please refer to...) Figure 1 To understand, the Penning ion source consists of an ion source base 1 and an ion generating chamber disposed on the ion source base 1. The ion generating chamber includes: an ion source cathode 3, a thermally activated electron emission source, an anode cylinder 7, and an ion source cathode pair 9. The ion source cathode 3 is disposed at one end of the ion generating chamber and connected to the ion source base 1. The ion source cathode pair 9 is disposed at the other end of the ion generating chamber. The anode cylinder 7 and the thermally activated electron emission source are disposed between the ion source cathode 3 and the ion source cathode pair 9. The anode cylinder 7 and the thermally activated electron emission source are electrically connected to an external power source. The thermionic electrons emitted by the thermally activated electron emission source under current heating serve as the starting electrons for each pulse of the Penning ion source. The working method of the Penning ion source includes the following steps:

[0047] After power-on, the thermionic electrons emitted by the thermally activated electron emission source under current heating are used as the starting electrons for each pulse of the Penning ion source.

[0048] In this embodiment of the invention, the ion source base 1 is a support structure for the ion source, used to fix and support the various components of the ion source; the ion generating cavity is the core working area of ​​the ion source, used to generate an ion beam.

[0049] In this embodiment of the invention, the thermionic electrons emitted by the thermally started electron emission source under current heating are used as the starting electrons for each pulse of the Penning ion source, thereby significantly shortening the pulse delay time, rise time and time jitter of the discharge current of the Penning ion source.

[0050] Optionally, the hot-start electron emission source includes a gas storage unit 4 and a hot cathode filament 5 connected in series. The gas storage unit 4 and the hot cathode filament 5 form an electrical circuit with the external power source. The operation method of the Penning ion source includes the following steps:

[0051] After power-on, the thermionic electrons emitted by the hot cathode filament 5 under current heating are used as the starting electrons for each pulse of the Penning ion source.

[0052] In this embodiment of the invention, the gas storage device 4 is connected in series with the hot cathode filament 5. The large current required for the operation of the gas storage device 4 is used to heat the hot cathode filament 5 in series, thereby realizing electron emission of the hot cathode without adding an extra neutron tube power supply.

[0053] In this embodiment of the invention, a hot cathode filament 5 is installed in the discharge space between the two cathodes of the Penning ion source. The thermionic emission of the hot cathode filament 5 under current heating serves as the starting electron for each pulse of the Penning ion source, thereby significantly shortening the pulse delay time, rise time, and time jitter of the cold cathode pulsed Penning ion source discharge current.

[0054] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A Penning ion source, characterized in that, The Penning ion source consists of an ion source base (1) and an ion generating cavity disposed on the ion source base (1). The ion generating cavity includes: an ion source cathode (3), a thermally activated electron emission source, an anode cylinder (7), and an ion source cathode (9). The ion source cathode (3) is located at one end of the ion generating chamber and connected to the ion source base (1). The ion source cathode (9) is located at the other end of the ion generating chamber. The anode cylinder (7) and the hot-start electron emission source are located between the ion source cathode (3) and the ion source cathode (9). The anode cylinder (7) and the hot-start electron emission source are electrically connected to an external power source. The hot-start electron emission source includes a gas storage device (4) and a hot cathode filament (5) connected in series, and the gas storage device (4) and the hot cathode filament (5) form an electrical circuit with the external power source. The ion source base (1) is provided with a first electrode hole, and a filament feed electrode (2) is installed in the first electrode hole. One end of the filament feed electrode (2) is electrically connected to the external power supply, and the other end of the filament feed electrode (2) is electrically connected to the gas storage device (4). The thermionic electrons emitted by the thermally started electron emission source under current heating serve as the starting electrons for each pulse of the Penning ion source. The thermionic electrons emitted by the hot cathode filament under current heating serve as the starting electrons for each pulse of the cold cathode pulse Penning ion source.

2. The Penning ion source as described in claim 1, characterized in that, The ion source base (1) is provided with a second electrode hole, and a support electrode rod (6) is installed in the second electrode hole. One end of the support electrode rod (6) is electrically connected to the external power source, and the other end of the support electrode rod (6) is electrically connected to the anode cylinder (7).

3. The Penning ion source as described in claim 1, characterized in that, The ion source base (1) has a first cathode limit groove in the middle, the axis of the first cathode limit groove coincides with the ion source base (1), and the ion source cathode (3) is disposed in the first cathode limit groove.

4. The Penning ion source as described in claim 3, characterized in that, The ion source cathode (3) has a receiving groove, and a magnet (12) is disposed in the receiving groove.

5. The Penning ion source as described in claim 1, characterized in that, The ion generating chamber further includes an ion source shell (8), and the outer peripheral opening of the ion source base (1) is provided with a shell limiting groove. One end of the ion source shell (8) is fitted with the limiting groove of the ion source base (1).

6. The Penning ion source as described in claim 5, characterized in that, The ion generating chamber also includes a magnetic ring or magnetic cylinder (10) and an ion source extraction electrode (11). The other end of the ion source shell (8) is provided with a second cathode limit groove. The ion source cathode (9), the magnetic ring or magnetic cylinder (10), and the ion source extraction electrode (11) are sequentially stacked and installed in the second cathode limit groove of the ion source shell (8).

7. A method for operating a Penning ion source, characterized in that, The working method of the Penning ion source is applied to the Penning ion source as described in any one of claims 1 to 6; the working method of the Penning ion source includes the following steps: After power-on, the thermionic electrons emitted by the thermally activated electron emission source under current heating are used as the activation electrons for each pulse of the Penning ion source.

8. The working method of the Penning ion source as described in claim 7, characterized in that, The hot-start electron emission source includes a gas storage unit (4) and a hot cathode filament (5) connected in series. The gas storage unit (4) and the hot cathode filament (5) form an electrical circuit with the external power source. The working method of the Penning ion source includes the following steps: After power-on, the thermionic electrons emitted by the hot cathode filament (5) under current heating are used as the starting electrons for each pulse of the Penning ion source.

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