2–6 Feb 2009
Chamonix
Europe/Zurich timezone
DISCLAIMER “The Chamonix workshop was an open exchange of views and opinions. All the presentations made at the workshop are available here. The views expressed in individual presentations do not necessarily represent those of the CERN management.”

Consequences of warm-up of a sector above 80K

4 Feb 2009, 10:40
20m
Le Majestic (Chamonix)

Le Majestic

Chamonix

Speaker

Pierre Strubin

Description

There may be circumstances when a sector has to be partially or totally warmed-up to temperatures above 80 K, that is when thermal dilatation starts to play a role. Some equipment have been identify as presenting a risk, like the non-conform "plug-in" modules in the arcs. Because of motion induced by thermal dilatation, the electrical (ElQA) quality control may also have to be done again after cool-down. The main reason identified so far for partial warm-up is the required maintenance of the cooling towers and the cryogenics plants. There is also the request from the vacuum group to periodically warm-up the beam screen to temperatures in the 100 K region to release and pump-out the gas crysorbed on the surface of the beam screen. Observed and expected temperature conditions and statistics on failures of PIMs in sectors which have been warmed-up will be presented in this contribution. Methods to detect buckled PIMs will be described, as well as a recommended strategy for consolidation. Finally, the required electrical quality controls will also be described.

Primary author

Pierre Strubin

Presentation materials