| Project/Area Number |
09309002
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
広領域
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| Research Institution | High Energy Accelerator Research Organization |
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Principal Investigator |
MORI Yoshiharu High Energy Accelerator Research Organization, Accelerator Laboratory, Professor, 加速器研究施設, 教授 (30124176)
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| Co-Investigator(Kenkyū-buntansha) |
SAKAE Takeji Proton Medical Research Center, University of Tsukuba Associate Professor, 陽子線医学利用研究センター, 助教授 (60162278)
TAMURA Keisuke Fukui Medical University, Associate Professor, 医学部, 助教授 (30212046)
IWASHITA Yoshihide The Institute for Chemical Reserch, Kyoto University, Research Associate, 化学研究所, 助手 (00144387)
NODA Akira The Institute for Chemical Research, Kyoto University, Profcssor, 化学研究所, 教授 (20114605)
TANABE Tetsumi High Energy Accelerator Research Organization, Accelerator Laboratory, Professor, 加速器研究施設, 教授 (20013394)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥30,100,000 (Direct Cost: ¥30,100,000)
Fiscal Year 1998: ¥5,500,000 (Direct Cost: ¥5,500,000)
Fiscal Year 1997: ¥24,600,000 (Direct Cost: ¥24,600,000)
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| Keywords | high permeability magnetic alloy / high accelerationg field gradient / accelerating cavity / impedance tuner / space charge eanceleration |
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| Research Abstract |
We have measured various characteristics of the different types of high permeability magnetic alloy (MA) core and found that a large accelerating field gradient of more than 100kV/m is possible with the MA cores. This is because the maximum allowable if magnetic flux of the MA core is more than 2kG which is ten times larger than that of the ferrite core. Based on these measurements, the prototype of the single-gap high gradient cavity whose total length is only 40cm has been developed. This cavity consits of 8 MA cores. With this cavity, a maximum voltage of 20kV, which is limited by the rf amplifier whose maximum power is 300kW, has been obtained at the resonant frequency of about 2.-3MIHz so far. This corresponds that the effective accelerating field gradient is 50kV/m, which is almost 5 times larger than that of the ordinary ferrite loaded if accelerating cavity. The Q value of this cavity is relatively low (Q-0.6), thus, its band width is very broad, which would be beneficial for acceleration of heavy ion. This cavity was installed at HIMAC and successfully accelerated heavy ions such as He, C, Ne ions up to several 100MeV/u.
We designed the "Impedance tuner" consisting of the inductive material, high permeability magnetic alloy (MA) cores, to cancel the space charge impedance in the longitudinal direction. It was installed in the KEK PS main ring. We observed the frequency shift of the coherent quadrupole oscillations and inferred the shift of the incoherent synchrotron oscillation. Total reactive impedance can be estimated as the coefficient between the shift and beam intensity. The measured impedance is reduced from-j2475OMEGA to-j1182OMEGA by the impedance tuner. We demonstrated the space charge impedance is compensated by the impedance tuner.
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