1994 Fiscal Year Final Research Report Summary
Generation of high-brightness electron beams with microfabricated field-emitter arrays
| Project/Area Number |
05452385
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
プラズマ理工学
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| Research Institution | Fukuoka Institute of Technology |
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Principal Investigator |
ISHIZUKA Hiroshi Faculty of Enigneering, Institute of Technology, Professor, 工学部, 教授 (50015517)
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| Co-Investigator(Kenkyū-buntansha) |
MASUZAKI Masaru Faculty of Science, Kanazawa University, Professor, 理学部, 教授 (10110602)
TAKEDA Kaoru Faculty of Enigneering, Institute of Technology, Asistant, 工学部, 助手 (90236464)
NAKAHARA Yuriko Faculty of Enigneering, Institute of Technology, Asistant, 工学部, 助手 (00237364)
TOKITA Masahiko Faculty of Enigneering, Institute of Technology, Professor, 工学部, 教授 (70099026)
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| Project Period (FY) |
1993 – 1994
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| Keywords | electron beam / microbeam / field-emitter array / emittance / brightness / free-electron laser / electron gun / microtriode |
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| Research Abstract |
Electron beams were extracted from microfabricated field-emitter arrays (FEA), accelarated up to 6 keV,and propagated over a distance of 1 m. Emittances of both the beam and beamlets were measured. The research concerned the following subjects :
1. Study of FEA performance : Characteristics of FEAs (the Spindt cathodes and microtriode arrays) were investigated. The current density on the cathode surface reached 40 A/cm^2 in 1 s regime. Microtriode arrays demonstrated the generation of parallel beam.
2. Stabilization and active control of emission current : A field effect transistor, introduced in series with the base of FEA,successfully stabilized and controlled the emission current.
3. Long range propagation of the beam : Electron beams extracted from the Spindt cathodea were propagated over 1 m and projected on a fluorescent screen. There a magnified image of the FEA was formed and separate images ofthe tips were observed saparately.
4. Emittance measurement : An electrostatic quadrupole lens was utilized to measure the emittance by elongating the image on the screen. Normalized emittances of the order of 10^<-7> m-rad and 2 x 10^<-9> m-rad were obtained for beams from high-current-density model Spindt cathodes and a beamlet therefrom, respectively.
5. Beam brightness : FEAs were damaged when the current density exceeded 40 A/cm^2 even in the pulsed mode. For this reason, the effort to increase the beam brightness has been suspended.
6. Improvement of FEAs : Collimated beams generated by microtriode arrays suffered from severe deflection due to stray electric fields at the exit. New FEAs, axi-symmetric in electrode configuration, are now being fabricated by our collaborators.
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