Vacuum status at KEKB
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Vacuum status at Vacuum status at KEKB KEKB Junji Haba Junji Haba
description
Vacuum status at KEKB. Junji Haba. KEKB Vacuum system. Vacuum monitoring. HER vacuum characteristics. Dependence on HER current is clear. ~ 0.3 (0A) 1.2 (1.3A) x10 -7 Pa 1nTorr (PEPII) =1.3 x 10 -7 Pa (KEKB) Far from “base pressure dominance” Not always simple linear relation - PowerPoint PPT Presentation
Transcript of Vacuum status at KEKB
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Vacuum status at KEKBJunji Haba
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KEKB Vacuum system
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Vacuum monitoring
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HER vacuum characteristicsDependence on HER current is clear. ~ 0.3 (0A) 1.2 (1.3A) x10-7Pa 1nTorr (PEPII) =1.3 x 10-7 Pa (KEKB)Far from base pressure dominanceNot always simple linear relationSome show a clear thermal behaviorBeam life time is a function not only of pressure but also luminosity or beam-beam effect.
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2004 June 14-20
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Discharge startsaround 0.9A at septum?Heat up at the feed back kicker structure
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Life time is predetermined by luminosity
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Beam-beam also affects the lifetimeLER currentHER beam size vs LER currentHER life and beam size
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LER vacuum characteristicsCurrent dependence is clear~ 0.2 (0A) 0.8 (1.6A) x10-7PaThermal behavior everywhere we have the parts with a special internal shape like GV, crotches, injection chamber etc.
