- BPKG.412449, which is the monitor on the target table (on 16/11/09): Beam is latched after 1st CNGS extraction because the monitor sees a position of +6.9mm (where it should be around 0). However, looking at the rest of the trajectory and muons profiles, it looks as if it is just wrong data. We tried to look at correctors functions, they all follow references. Jorg authorised us to bypass the BPKG.412449 BPM position surveillance (with MCS-CNGS role only). The BPM returns false position data for the vertical plane only, but we don't know why yet. Had to mask SIS interlock "DISABLED_BPM_COUNT" (with my name and role SPSOP).

- Most of the time when no CNGS beam is extracted, it comes from the server bmu40s which needs to be rebooted.

- It was observed during the 2009 run that the target moved by 1 mm horizontally (vertically it was OK). This was deduced from target scans. It was also seen with the beam looking at the corrections which had to be implemented during the year (in fact an horizontal  drift  of ~ 0.5 mm was found). The origin of it is not yet understood (ground motion?, temperature?).

Author: Elias Métral - AB/ABP
Last update: Thursday, April 29, 2010 07:17:54 PM
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