[BLAST_SHIFTS] Shift summary

From: Electronic Log Book (elog@blast05.lns.mit.edu)
Date: Sun Jul 06 2003 - 15:57:16 EDT


Operators: kohlm vziskin

VZ installed a heat-buster airplane-propeller-like fan in the Dtunnel to mix cold and hot air to obtain a smooth distribution of moderately warm air.
The result was that the hv crates haven't tripped anymore since.

We've started taking data from 9am, good runs 1293-1297.
They were charge.C'd and lrn'd with CRUNCH/v3/lrn

At about noon, alarmHandler indicates alarm for Crate_4, however no trip signalled on GUI.
At 1:30 we moved to do ABS field scans (see elog)
At 3pm crate_4 (L1) tripped, reset.
3:10 ca_start

Target comment: The main concern right now is the fact that the lower 6pole chamber vacuum is very high. It is as high as it was right before the negs were regenerated few days ago, which points to a very bad regeneration. Also, from my experience, the atomic beam intensity goes down as the background pressure increases in the abs and correspondingly the ligit goes down. However, the ligit is at a very high level right now ,1.5e-7 (typicaly it is at ~1.1e-7 level). And it keeps going up (it was 1.4e-7 in the morning). Looking back at the history, I could not find any jumps. It looks like like the ligit started smoothly rising sometime after midnight. Lower 6pol chamber pressure as I mention before was smoothly rising. At the same time, looking back both lig103 and lig104 are increasing. Either this is effect from ligit or there is a small leak in the chamber (is that possible) or a pump failure.



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