1987 Fiscal Year Final Research Report Summary
Development of an improved tubes fro electrostatic accelerators
| Project/Area Number |
60840002
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
核・宇宙線・素粒子
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| Research Institution | University of Tsukuba |
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Principal Investigator |
TAGISHI Yoshihiro Institute of Physics, Unibersity of Tsukuba, 物理学系, 助教授 (70015551)
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| Co-Investigator(Kenkyū-buntansha) |
ISHIHARA Toyoyuki Institute of Physics, University of Tsukuba, 物理学系, 助教授 (10013385)
FURUNO Kohhei Institute of Physics, University of Tsukuba, 物理学系, 助教授 (40015772)
YAGI Kohsuke Institute of Physics, University of Tsukuba, 物理学系, 教授 (60028107)
SEKI Seiji Institute of Physics, University of Tsukuba, 物理学系, 助教授 (60015542)
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| Project Period (FY) |
1985 – 1987
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| Keywords | Elctrostatic accelerator / accelerator tube / Vacuum breakdown / 電圧コンディショニング |
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| Research Abstract |
Discharges in the accelerator tubes during voltage conditioning and damages of the electrodes in a tandem accelerator bubes have been carefully observed to investigate the mechanism of coltage instability and of coltage conditioning. Discharge phenomena in the tubes are compared with those thus far studied in the small gap experiments. Reason of remarkable decrease of stable field gradient in the accelerator is discussed.
Mild melting of the electrode surface initiated from the anode side was commonly observed. Voltage conditioning is consideres to be effective for smmothening of the surface as well as to remove contaminants or adsorbed gases. However, abrupr discharge current during the conditioning sometimes creares new extrusions of microparticles which depress the field emission voltage. Then voltage conditioning makes no progress.
Creshing of energetic microparticles on the lectrode might be a prominent process which also creatr the micro protrusions and further microparticles. Microparticles should be effectively sweeped out before accelerated to high energies. An inclined field structrue of the tube is prefered for such errects.
Hydorgen discharge cleaning rechnique is feeective in particular for tubes exposed to atomosphere for long period or new ones to improve the conditioning.
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