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VERSION:2.0
PRODID:-//Memento EPFL//
BEGIN:VEVENT
SUMMARY:"Multipacting and Plasma Disturbance Effects in the PSI High Inten
 sity Ringcyclotron"
DTSTART:20140623T103000
DTEND:20140623T113000
DTSTAMP:20260509T235639Z
UID:56a2e95984423cf43eb617aab1b253c62c1198a3d5808358ead49311
CATEGORIES:Conferences - Seminars
DESCRIPTION:Dr Andreas Adelmann & Dr Lukas Stingelin\nPaul Scherrer Instit
 ut - Villigen\, CH\nThe PSI high intensity proton accelerator delivers rou
 tinely a 590 MeV beam with an intensity of 2.2 mA for Meson- Muon- and Neu
 tron-production. Since 2010\, problems caused by interaction between RF po
 wer leaking out from the cavities and the electrostatic septa at the injec
 tion and extraction region are affecting the machine operation. As an indi
 rect influence of the RF fields outside the cavities\, plasma clouds in th
 e peripheral area of magnet poles are generated. Accelerated plasma ions s
 puttered metallic atoms form the vacuum chamber wall\, which then covered 
 the insulator surface with an electrically conductive layer. In autumn 201
 3\, strong multipacting in the 150MHz flattop cavity destroyed rf-contacts
  at the coupling-loop and caused a long down-time of the accelerator facil
 ity. Painting of the critical cavity walls with colloidal graphite finally
  helped to reduce the multipacting. However\, one of the ionization monito
 rs still shows high radiation values which depend on the voltage in the fl
 attop cavity. Since these effects can be critical for the accelerator faci
 lity\, an effort must be made to better understand and solve the problems.
  In the past we have developed models for large scale precise beam and ele
 ctromagnetic modelling and simulation. We will give a brief introduction t
 o these models and put them into the context of the multipacting problem.
LOCATION:PPB 019
STATUS:CONFIRMED
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