CN102709139A - Field emission ion source for outputting monatomic hydrogen ion beam - Google Patents
Field emission ion source for outputting monatomic hydrogen ion beam Download PDFInfo
- Publication number
- CN102709139A CN102709139A CN2012101619626A CN201210161962A CN102709139A CN 102709139 A CN102709139 A CN 102709139A CN 2012101619626 A CN2012101619626 A CN 2012101619626A CN 201210161962 A CN201210161962 A CN 201210161962A CN 102709139 A CN102709139 A CN 102709139A
- Authority
- CN
- China
- Prior art keywords
- field emission
- foam metal
- ion source
- active thin
- emission array
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Landscapes
- Electron Sources, Ion Sources (AREA)
Abstract
The invention provides a field emission ion source for outputting a monatomic hydrogen ion beam, belonging to the technical field of a small specific ion source. The field emission ion source mainly comprises a field emission array, a foam metal active thin board and an acceleration electrode. The foam metal active thin board is placed on the field emission array after being isolated through an insulating material; the surface of the foam metal active thin board is parallel to the surface of the field emission array; and the acceleration electrode is placed on the foam metal active thin board. When the field emission ion source works, the working voltage of the field emission array is less than 1kV, so that the electric field on a tip surface is 15-20V/nm. The foam metal active thin board is externally connected with low-voltage power supply about minus 700V relative to the upper surface of the field emission array, and the acceleration electrode is externally connected with high-voltage pulse power supply more than minus 10kV relative to the foam metal active thin board. With the adoption of the field emission ion source provided by the invention, the hydrogen (including isotopic deuterium or tritium) atomic ion beam with a high ratio can be output from the acceleration electrode, the working voltage of the field emission array is reduced, so that the field emission array is prevented from being burnt.
Description
Technical field
The present invention relates to a kind of emission ion source, particularly a kind of field emission ion source that is exclusively used in output mon-H ion beam belongs to small-sized extraordinary technology of ion source field.
Background technology
Neutron tube is a kind of neutron source of safe and portable, compares with common isotope neutron source, and its power spectrum monochromaticjty is good, no γ background and can produce pulsed neutron, the time spent can not turn-off, thus protection easily, storage administration and convenient transportation.Neutron tube all is integrated in ion source, accelerator, target and pressure regulation system in the sealed tube, need not vaccum-pumping equipment and compressed air source unit during work.Neutron tube can be widely used in defence engineering and worker, farming, doctor field, particularly military project and safety inspection field.Use in the open air neutron tube the time, the portability of neutron tube seems even more important, but it is all bulky much to have at present the neutron source of high yield, can only in the laboratory, move.
The neutron yield of neutron tube is with wherein critical component--the monatomic ratio with molecular deuterium ions that the deuterium ion source produces is relevant; Under same accelerating voltage and beam current density; The monatomic deuterium ion ratio that ion source produces is high more; Neutron yield is just big more, that is to say that the sensitivity of detection and efficient are also high more.For example, a branch of 50%D that contains
+And 50%D
2 +Ion beam use 100%D with the neutron yield ratio that 100 KeV energy bombardments tritium target obtains
+The neutron yield that bundle obtains under same bombarding conditions is low by 48%, i.e. D under this condition
2 +Ion does not almost have and tritium target generation nuclear reaction.The ion source of neutron tube basically all is based on gas discharge principle at present, and like penning source, radio-frequency ion source etc., wherein the penning source accounts for leading.Simple in structure, advantages such as operating air pressure is low, electric power system is simple, reliable operation that Penning ion source has, but the monatomic ion proportion that its ionization produces is very low, and for example certain penning source is operated in 2 * 10
-1Pa H
2Air pressure, when discharging current is 2 A, the H of output
+: H
2 +: H
3 +=1:1.7:6.3.To obtain the high yield neutron in the case, the high line ion bombardment target that the penning source must be exported, but this causes ion sputtering and secondary phenomenon serious again, and reason is by H
2 +The yield of the metal surface secondary electron that is caused almost is two times of proton caused under the same energy secondary electron.
Because present various ion sources can't satisfy the demand of high monatomic ion yield and neutron tube (and accessory) miniaturization simultaneously, the U.S. took the lead in 2005 the field emission ion source that uses direct current pulse power source is used for neutron tube.Document (B.B. Johnson; P.R. Schwoebel; C.E. Holland, P.J. Resnick, K.L. Hertz; D.L. Chichester, Nuclear Instruments & Methods in Physics Research Section a-Accelerators Spectrometers Detectors and Associated Equipment 663/1 (2012) 64; P.R. Schwoebel; Applied Physics Letters 87/5 (2005) and A. Persaud, I. Allen, M.R. Dickinson; T. Schenkel; R. Kapadia, K. Takei, A. Javey; The structure of the field emission ion source of Journal of Vacuum Science & Technology B 29/2 (2011)) announcing that is used for neutron tube is as shown in Figure 1, is made up of substrate (5), pointed cone array (6), insulating barrier (7), perforate grid (8) and tritium target (9).The basic principle of emission ion source is like this, and it is to utilize extremely sharp keen tip to obtain very high electric field strength, thereby makes gas molecule ionization or from the form desorption of tip end surface with ion, thereby forms emission of ions.Discover that tip end surface electric field strength is high more, the ratio of emission atomic deuterium ion is just big more.When most advanced and sophisticated electric field strength reaches 30 V/nm, most advanced and sophisticated emission H
+, H
2 +Ratio is about 4:1, thereby the neutron tube of use emission ion source preparation can obtain higher neutron yield, and because an emission ion source adopts simple relatively DC power supply to drive, very practical.
A big problem also can appear in when being used for neutron tube, being in operation of emission ion source at present: field emission array is when operation; When reaching sufficient intensity (30 V/nm), the emission tip electric field makes atomic ion emission time; The electric field strength of gate surface also causes grid divergent bundle bombardment pointed cone, causes the pointed cone large tracts of land to be burnt.This problem is fatal for the ion source long-term safety service requirement of neutron tube.
The object of the invention will solve an emission ion source exactly after heightening voltage and reaching height ratio hydrogen atom ion output and require; Because of the high electric field strength in tip causes the problem that the bombardment of grid emitting electrons is prone to burn, make an emission ion source steady operation and can launch height ratio hydrogen atom ion beam.Addressing this problem the method that generally adopts abroad is to improve the smooth degree of gate surface, thereby the emission of the electronics of suppressor grid suppresses the bombardment of duplet field emission array.
Summary of the invention
For overcoming the above problems, the present invention has increased a reactive metal in a tradition emission ion source.The effect of reactive metal is to make molecular ion beam under catalytic action, be cracked into the atomic ion beam emission, has reduced the applied electric field intensity of field emission array like this, makes it under the safe electric field strength of 15 ~ 20 V/nm, launch hydrogen molecular ion.When these molecular ions pass through reactive metal, because catalytic action makes molecular ion be decomposed into the atomic ion emission.After using this improved ion source, both improve the yield of neutron tube, can prolong the working life of field emission array again.
A kind of field emission ion source that is used to export the mon-H ion beam of the present invention; Its structure is as shown in Figure 2, comprises field emission array, it is characterized in that; Also comprise active thin plate of a foam metal and intensifying ring; The active thin plate of said foam metal is positioned on the field emission array after isolating through an insulating material, and its surface is parallel with the field emission array surface; Said intensifying ring places on the active thin plate of foam metal.
Further, the field emission ion source of mon-H ion beam is exported in above-mentioned being used to, and it is characterized in that said field emission array comprises carbon nano-tube field emission array, metal pointed cone field emission array or silicon tip awl field emission array.
Further, the field emission ion source of mon-H ion beam is exported in above-mentioned being used to, and it is characterized in that the material of the active thin plate of said foam metal is Fe, Co, Ni or Ti.
Further, the field emission ion source of mon-H ion beam is exported in above-mentioned being used to, and it is characterized in that the active gauge of sheet of said foam metal≤10 mm, average pore size>=0.2 mm, specific area>=250 m
2/ m
3
During work, the operating voltage of adjustment field emission array makes the tip end surface electric field be in 15 ~ 20 V/nm and gets final product.The low-tension supply of the active thin plate of foam metal about with respect to external-700 V of the upper surface of field emission array, intensifying ring is with respect to the high-voltage pulse power source more than external-10 kV of the active thin plate of foam metal.Adopt ion source of the present invention to export height ratio hydrogen (comprising its isotope deuterium or tritium) atomic ion beam, and it is unlikely to burn to reduce the protection of field emission array operating voltage from intensifying ring.
Description of drawings
Existing emission ion source cross-sectional view of Fig. 1.
Fig. 2 field emission ion source cross-sectional view that is used to export the mon-H ion beam of the present invention.
Wherein, the mark implication of each accompanying drawing is:
1-field emission array, 2-insulating material, the active thin plate of 3-foam metal, 4-intensifying ring, 5-substrate, 6-pointed cone array, 7-insulating barrier, 8-perforate grid and 9-tritium target.
Embodiment
Below in conjunction with embodiment and accompanying drawing 2, the present invention is described in further detail.
Embodiment one:
As shown in Figure 2, on metal pointed cone field emission array 1, isolate the active thin plate 3 of placement one Ni foam metal with the thick insulating material 2 of 1 mm, its thickness is 2 mm, average pore size=0.23 mm, specific area=5800 m
2/ m
3Also have an intensifying ring 4 to place on the active thin plate 3 of Ni foam metal in addition.In the deuterium gas atmosphere; Connect external power supply and start this ion source; Because the catalytic action of the active thin plate 3 of Ni foam metal; The deuterium molecule ion of metal pointed cone field emission array 1 emission can be transformed into the D-atom ion, available omegatron mass spectrometer test D-atom and molecular ion beam ratio after intensifying ring 4 quickens.After starting field emission array, the low-tension supply of the active thin plate 3 of Ni foam metal about with respect to external-700 V of the upper surface of field emission array 1, intensifying ring 4 is with respect to the high-voltage pulse power source more than active thin plate 3 external-10 kV of Ni foam metal.During the active thin plate 3 of no Ni foam metal, the ratio of output D-atom and molecular ion ion beam is 1:99, add the active thin plate 3 of Ni foam metal afterwards the ratio of D-atoms and molecular ion beam become 1:0.6.
Embodiment two:
As shown in Figure 2, on silicon tip awl field emission array 1, isolate the active thin plate 3 of placement one Fe foam metal with the thick insulating material 2 of 1 mm, its thickness is 3 mm, average pore size=0.7 mm, specific area=1580 m
2/ m
3Also have an intensifying ring 4 to place on the active thin plate 3 of Fe foam metal in addition.In the deuterium gas atmosphere; Connect external power supply and start this ion source; Because the catalytic action of the active thin plate 3 of Fe foam metal; The deuterium molecule ion of silicon tip awl field emission array 1 emission can be transformed into the D-atom ion, available omegatron mass spectrometer test D-atom and molecular ion beam ratio after intensifying ring 4 quickens.After starting field emission array, the low-tension supply of the active thin plate 3 of Fe foam metal about with respect to external-700 V of the upper surface of field emission array 1, intensifying ring 4 is with respect to the high-voltage pulse power source more than active thin plate 3 external-10 kV of Fe foam metal.During the active thin plate 3 of no Fe foam metal, the ratio that records output D-atom and molecular ion ion beam is 1:99, add the active thin plate 3 of Fe foam metal afterwards the ratio of D-atoms and molecular ion beam become 1:1.
Embodiment three:
As shown in Figure 2, on carbon nano-tube field emission array 1, isolate the active thin plate 3 of placement one Co foam metal with the thick insulating material 2 of 1 mm, its thickness is 8 mm, average pore size=1.6 mm, specific area=250 m
2/ m
3Also have an intensifying ring 4 to place on the active thin plate 3 of Co foam metal in addition.In the deuterium gas atmosphere; Connect external power supply and start this ion source; Because the catalytic action of the active thin plate 3 of Co foam metal; The deuterium molecule ion of carbon nano-tube field emission array field emission array 1 emission can be transformed into the D-atom ion, available omegatron mass spectrometer test D-atom and molecular ion beam ratio after intensifying ring 4 quickens.After starting carbon nano-tube field emission array 1, the low-tension supply of the active thin plate 3 of Co foam metal about with respect to external-700 V of the upper surface of field emission array, intensifying ring 4 is with respect to the high-voltage pulse power source more than active thin plate 3 external-10 kV of Co foam metal.During the active thin plate 3 of no Co foam metal, the ratio that records output D-atom and molecular ion ion beam is 1:99, add the active thin plate 3 of Co foam metal afterwards the ratio of D-atoms and molecular ion beam become 1:1.5.
Embodiment four:
As shown in Figure 2, on carbon nano-tube field emission array 1, isolate the active thin plate 3 of placement one Ti foam metal with the thick insulating material 2 of 1 mm, its thickness is 5 mm, average pore size=0.95 mm, specific area=500 m
2/ m
3Also have an intensifying ring 4 to place on the active thin plate 3 of Ti foam metal in addition.In the deuterium gas atmosphere; Connect external power supply and start this ion source; Because the catalytic action of the active thin plate 3 of Ti foam metal; The deuterium molecule ion of carbon nano-tube field emission array field emission array 1 emission can be transformed into the D-atom ion, available omegatron mass spectrometer test D-atom and molecular ion beam ratio after intensifying ring 4 quickens.After starting field emission array, the low-tension supply of the active thin plate 3 of Ti foam metal about with respect to external-700 V of the upper surface of carbon nano-tube field emission array 1, intensifying ring 4 is with respect to the high-voltage pulse power source more than active thin plate 3 external-10 kV of Ti foam metal.During no Ti foam metal active board 3, the ratio that records output D-atom and molecular ion ion beam is 1:99, add Ti foam metal active board 3 afterwards the ratio of D-atoms and molecular ion beam become 1:1.5.
Claims (4)
1. field emission ion source that is used to export the mon-H ion beam; Comprise field emission array (1), it is characterized in that, also comprise active thin plate (3) of a foam metal and intensifying ring (4); After the active thin plate of said foam metal (3) is isolated through an insulating material (2); Be positioned on the field emission array (1), its surface is parallel with the field emission array surface, and said intensifying ring (4) places on the active thin plate of foam metal.
2. the field emission ion source that is used to export the mon-H ion beam according to claim 1 is characterized in that, said field emission array (1) can be carbon nano-tube field emission array, metal pointed cone field emission array or silicon tip awl field emission array.
3. the field emission ion source that is used to export the mon-H ion beam according to claim 1 is characterized in that the material of the active thin plate of said foam metal (3) is Fe, Co, Ni or Ti.
4. the field emission ion source that is used to export the mon-H ion beam according to claim 1 is characterized in that thickness≤10 mm, average pore size>=0.23 mm, the specific area>=250 m of the active thin plate of said foam metal (3)
2/ m
3
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210161962.6A CN102709139B (en) | 2012-05-23 | 2012-05-23 | Field emission ion source for outputting monatomic hydrogen ion beam |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210161962.6A CN102709139B (en) | 2012-05-23 | 2012-05-23 | Field emission ion source for outputting monatomic hydrogen ion beam |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102709139A true CN102709139A (en) | 2012-10-03 |
| CN102709139B CN102709139B (en) | 2014-09-17 |
Family
ID=46901815
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210161962.6A Expired - Fee Related CN102709139B (en) | 2012-05-23 | 2012-05-23 | Field emission ion source for outputting monatomic hydrogen ion beam |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102709139B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104332375A (en) * | 2014-09-05 | 2015-02-04 | 西安奥华电子仪器有限责任公司 | Ion source digital PID control parameter self-setting system and method |
| CN106841706A (en) * | 2017-03-31 | 2017-06-13 | 中国工程物理研究院电子工程研究所 | A kind of ion gun test fixture |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1265230A (en) * | 1997-07-22 | 2000-08-30 | 布莱克光电有限公司 | Inorganic hydrogen compounds, separation methods, and fuel applications |
| CN202721105U (en) * | 2012-05-23 | 2013-02-06 | 四川大学 | Field emission ion source used for outputting monatomic hydrogen ion beam |
-
2012
- 2012-05-23 CN CN201210161962.6A patent/CN102709139B/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1265230A (en) * | 1997-07-22 | 2000-08-30 | 布莱克光电有限公司 | Inorganic hydrogen compounds, separation methods, and fuel applications |
| CN202721105U (en) * | 2012-05-23 | 2013-02-06 | 四川大学 | Field emission ion source used for outputting monatomic hydrogen ion beam |
Non-Patent Citations (2)
| Title |
|---|
| B.BARGSTEN JOHNSON.ETC: "Field ion source development for neutron generators", 《NUCLEAR INSTRUMENTS AND METHODS IN》 * |
| I.SOLANO.ETC: "Field desorption ion source development for neutron generators", 《NUCLEAR INSTRUMENTS AND METHODS IN》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104332375A (en) * | 2014-09-05 | 2015-02-04 | 西安奥华电子仪器有限责任公司 | Ion source digital PID control parameter self-setting system and method |
| CN104332375B (en) * | 2014-09-05 | 2016-12-28 | 西安奥华电子仪器股份有限公司 | Ion source digital IIR filters parameter self-tuning system and method |
| CN106841706A (en) * | 2017-03-31 | 2017-06-13 | 中国工程物理研究院电子工程研究所 | A kind of ion gun test fixture |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102709139B (en) | 2014-09-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8148922B2 (en) | High-current DC proton accelerator | |
| Di Mauro et al. | Photoelectron backscattering effects in photoemission from CsI into gas media | |
| Jammes et al. | Research activities in fission chamber modeling in support of the nuclear energy industry | |
| Freemire et al. | Pressurized rf cavities in ionizing beams | |
| CN111135477A (en) | Boron neutron capture treatment system based on electron accelerator | |
| CN102709139B (en) | Field emission ion source for outputting monatomic hydrogen ion beam | |
| CN102709140B (en) | Gas discharging type ion source for neutron pipe | |
| Zhou et al. | Electron gun system for NSC KIPT linac | |
| CN202721105U (en) | Field emission ion source used for outputting monatomic hydrogen ion beam | |
| CN202721106U (en) | Gas discharge type ion source for neutron tube | |
| Aleinik et al. | Dark currents of a tandem accelerator with vacuum insulation | |
| Ren et al. | Milliampere He 2+ beam generator using a compact GHz ECRIS | |
| Bhatt et al. | Relative partial ionization cross sections of N 2 O under 10–25-keV electron impact | |
| Williams et al. | Testing of a H2+‐enriched ion source for deuterium simulation | |
| Venuti et al. | Radiation aging studies of CO 2 hydrocarbon mixtures for the SLD drift chamber | |
| Tian et al. | Prototype of a large neutron detector based on MWPC | |
| Bevington et al. | Investigation of some properties of multiware proportional chambers with planar cathodes | |
| Peskov | Secondary processes in gas-filled counters. II | |
| Reifenschweiler | A high output sealed-off neutron tube with high reliability and long life | |
| Belchenko et al. | INITIAL HIGH VOLTAGE TESTS AND BEAM INJECTION EXPERI-MENTS ON BINP PROTON TANDEM-ACCELERATOR. | |
| Andreev et al. | Ultracold neutron detector for the spectrometer of a neutron lifetime measuring | |
| Baxter et al. | Deuterium ion extraction and neutron production from a piezoelectric transformer plasma source | |
| Xiao et al. | An ultra-low energy electron beam ion trap in Shanghai | |
| Nishimori et al. | Development of a High-Brightness and High-Current Electron Gun for High-Flux γ-Ray Generation | |
| Vogt | Accelerator Systems for Activation Analysis—A Comparative Survey |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20140917 Termination date: 20150523 |
|
| EXPY | Termination of patent right or utility model |