[BLAST_SHIFTS] Shift summary 02/06/2005 C (17-1)

From: Electronic Log Book (elog@blast05.lns.mit.edu)
Date: Mon Feb 07 2005 - 01:58:54 EST


Operator: akdogan

During the first half of the beam, CCR continued to tune the beam until 8pm.
The beam condition didn't improve compared to Bill's notes. Since 8pm,
resumed data taking mainly for testing purposes. Meanwhile, CCR continues
to tweak the beam slightly.

Main problem:
- The BQM rates are about 3 times higher than what we had before shutdown.

Major problems:
- WC can not hold HVs at this condition for an extended period of time
- One dead TOF channel
- One of the WC TDC spectra shows a flat high rate for channels<500
- Singles trigger can not get through level-2 trigger (trigger board related?)

In the meantime, tested the new frontend under harsh conditions. These
initial tests showed that new CPU boards can handle 2 KHz rate, and
they can transfers data at a sustained rate of 3MB/sec which are about
a factor of 6 higher than the values with the old system. The deadtime
with buffering is less than 1% for l2-trig<400Hz, and about 1% with <1kHZ.

Scanned the Compton laser and collimator. Although, the results are not
reliable/precise due to a number of reasons, it appears to be in the
right neighborhood; 65%.

Turned the beam to CCR for more tuning, as the data without WC will not
be useful. The overnight shift is canceled.

Taylan



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