[BLAST_SHIFTS] Shift summary 02/09/2004 E (16-20)

From: Electronic Log Book (elog@blast05.lns.mit.edu)
Date: Mon Feb 09 2004 - 00:00:01 EST


Operators: hasell ---- ----

Bill Franklin and Peter Karpius worked on setting up the unpolarised gas system / buffer system. There is a bad/broken valve which needs to be fixed. Eventually, with some help from Aki they got it running but not clear how much gas is flowing and the regulation of the buffer pressure is not good. Needs some work and perhaps better documentation.

Changed the WC operating voltages from 3800 to 3850 V corresponding to the values which were found to have better efficiency just before Christmas.

FASTBUS crate for the right sector has a faulty power supply. +/- 15 V missing. Phoned Townsend who call Alan Carson who came in to fix it. Rather than repair or replace the power supply he spliced a small portable supply into the line. At some point this should be repaired.

CODA running now and did a few short runs starting with 4572 to see how things were working.

HV crate #1 hung and had to be power cycled.

Left sector WC looks okay but right sector noisey. Tried changing configuration files but this didn't help. Accessed South Hall and found left sub-detector open and right closed. Closed left and also remove covers from target chamber windows. Left covers on WC though for the moment. WC looks okay now. S/B not great ~2:1 but for zero field figure this is okay.

Eventually noticed that left TOF singles and coincidence rates normal but right sector had normal singles rates but coincidence rates down by a factor of 50. Peter and Karen looked into it but no joy. This has to be sorted out some time too.

No trig 1 or trig 2 events. Probably related to lack of coincidence rates from right TOF's but should be investigated further. Karen increased the prescale factor on trig3 to 100 and trig 5 to 1000. Trigger rate is now around 30 Hz.

FLASHER appears to be on but flasher - trigger 7 is not counting?

Initially nsed was not working by Chi pointed out that the BLAST_PARAM variable has to be set to /home/daq/blast/cvs_3.0/Blast_Params and only run on the spuds and things are okay. WC events looks reasonable. Some events have lots of hits but most are quite clean. Should be reasonable data set for calibration.

WC L14 and R24 wouldn't hold 3850 so lowered to 3800 V. Ocassionally they still trip but it is tolerable.

Tested WC with different thresholds: run 4579 - 3 V, 4580 - 5 V, and 4581 - 4 V. Decided I liked 5 V best.

Another access to remove WC covers from front windows only.

Data alarm (yellow box) not working. Starts up when you setup CODA but crashes almost immediately.

OnlineGUI needs to be set up to spy on the correct data set for this year.

Other than that things working reasonably quickly for starting up after being down for almost 2 months.

Plan is to collect WC calibration data for the rest of the evening with zero magnetic field.

South Hall will be opened around 07:30 Monday morning. WC covers and target chamber window covers should be put back on.

Things to fix or investigate: RTOF coincidences, trigger types 1, 2, and 7, valve on unpol. system, buffer documentation, FASTBUS power supply, OnlineGUI, data alarm, change BLAST_PARAM in login script,



This archive was generated by hypermail 2.1.2 : Mon Feb 24 2014 - 14:07:30 EST