| Project/Area Number |
16540272
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Particle/Nuclear/Cosmic ray/Astro physics
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| Research Institution | High Energy Accelerator Research Organization |
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Principal Investigator |
TOYAMA Takeshi High Energy Accelerator Research Organization, Accelerator Laboratory, Associate professor (30207641)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAYAMA Ken High Energy Accelerator Research Organization, Accelerator Laboratory, Professor (20163321)
OHMI Kazuhito High Energy Accelerator Research Organization, Accelerator Laboratory, Associate professor (10194292)
LEE Seishu High Energy Accelerator Research Organization, Accelerator Laboratory, Assistant professor (20353360)
MIURA Takako High Energy Accelerator Research Organization, Assistant professor (90370072)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 2005: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2004: ¥800,000 (Direct Cost: ¥800,000)
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| Keywords | collective beam instability / feedback damper / electron-cloud / head-tail instability |
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| Research Abstract |
1. Instability analysis including the electron cloud effect was performed using the KEK-PS and J-PARC parameters.
2. A kicker parameter was studied for the J-PARC ring.
3. Stability analysis of the head-tail instabilities with feedback dampers, using two-particle model, and the J-PARC parameters.
4. Experiments at the KEK-12 GeV-PS Main Ring at the injection energy (500 MeV)
(1) Experiment of feedback damping with one monitor and one kicker.
Succeeded in damping a head-tail instability ( mode 0, growth-rate ~30 ms) using an analog circuit.
(2) A digital signal processing (fast processing with a Field Programmable Gate Array) and an analog signal processing were applied and compared. Similar damping times were achieved.
(3) Stability was analyzed with one-particle model.
(4) Experiment of feedback damping with two monitors and one kicker with a digital signal processing
The instability was stabilized. But strong damping effect could not be studied because the RF amplifier was saturated with a large remaining COD (closed orbit distortion) signal. Elimination of the COD component is the next subject.
5. Analysis of two-monitor and two-kicker configuration
(1) Exact solution was obtained for the stability with two monitors and one kicker, using one particle model. The solution for the fast damping regime is far different from the approximate solution for the small damping regime, and realizes one-or two-turn damping if appropriate parameters are chosen. Issues are (a) oscillation amplitude increases over the initial amplitude for a moment; (b) the stability region is restricted.
(2) The numerical solution was obtained for the stability with two monitors and two kickers, using one particle model. Both above issues are resolved in this case. Analysis with the two-particle model and multi particle simulation is the next subject.
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