Vacuum status at Vacuum status at KEKB KEKB Junji Haba Junji Haba
Jan 09, 2016
Vacuum status at KEKBJunji Haba
KEKB Vacuum system
Vacuum monitoring
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.
2004 June 14-20
Discharge startsaround 0.9A at septum?Heat up at the feed back kicker structure
Life time is predetermined by luminosity
Beam-beam also affects the lifetimeLER currentHER beam size vs LER currentHER life and beam size
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.