"Multipacting and Plasma Disturbance Effects in the PSI High Intensity Ringcyclotron"
Event details
| Date | 23.06.2014 |
| Hour | 10:30 › 11:30 |
| Speaker |
Dr Andreas Adelmann & Dr Lukas Stingelin Paul Scherrer Institut - Villigen, CH |
| Location |
PPB 019
|
| Category | Conferences - Seminars |
The PSI high intensity proton accelerator delivers routinely a 590 MeV beam with an intensity of 2.2 mA for Meson- Muon- and Neutron-production. Since 2010, problems caused by interaction between RF power leaking out from the cavities and the electrostatic septa at the injection and extraction region are affecting the machine operation. As an indirect influence of the RF fields outside the cavities, plasma clouds in the peripheral area of magnet poles are generated. Accelerated plasma ions sputtered metallic atoms form the vacuum chamber wall, which then covered the insulator surface with an electrically conductive layer. In autumn 2013, strong multipacting in the 150MHz flattop cavity destroyed rf-contacts at the coupling-loop and caused a long down-time of the accelerator facility. Painting of the critical cavity walls with colloidal graphite finally helped to reduce the multipacting. However, one of the ionization monitors still shows high radiation values which depend on the voltage in the flattop cavity. Since these effects can be critical for the accelerator facility, 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 electromagnetic modelling and simulation. We will give a brief introduction to these models and put them into the context of the multipacting problem.
Practical information
- Informed public
- Free
Organizer
- Prof. P. Ricci
Contact
- Prof. P. Ricci