[BLAST_SHIFTS] Shift summary 02/12/2004 A (0-4)

From: Electronic Log Book (elog@blast05.lns.mit.edu)
Date: Thu Feb 12 2004 - 04:06:36 EST


Operators: ajmasch ---- ----

no data taken this shift.

CCR was beam tuning until 1:00am or so. when they handed over the beam, the tune was bad. the beam life-time was about 10 minutes; the top BQM was around 225 or so while the other three were about 50. CCR thinks that the bad tune might have something to do with the power burp that happened to the quads and snakes early wednesday morning. they tried cycling everything and ran the original beam solution many times but all to no avail.

anyway, like i said, at 1:00am, we got the beam. but now's where the real fun starts. for the next three hours or so, i fought near constant HV tripping in numerous places. plus, broken pipes started appearing like crazy in the "left WC" HV crate (i.e. the one closest to the wall); they didn't go away, either, when i types "./BOOT". i think i made 12 trips to the d-tunnel to power cycle them before i gave up (can you reboot the HV power from the counting bay somehow???). after a power cycle, the broken pipes might (or might not) disappear. it didn't really matter, cause as soon as you tried to turn on or off HV to that crate, a broken pipe pretty much immediately re-appeared.

i saw that non-WC cables are plugged into slots 12, 13, and 14 in the left WC crate. maybe these are somehow causing the problem? i would have tried to disable them, except that the nearly constant broken pipes wouldn't let me open up that crate's HV screen to do so.

also, i think that the forward LADS are causing some HV problems. amidst the confusion it was hard to say for sure.

it's very hard to debug tripping HV cables when, for example, the orange "HV Crate L1" button says "trip" but none of the yellow buttons underneath shows a trip. this was also happening on "HV Crate L2" and "HV Crate R2".

anyway, CCR said that they would like to tune for a few more hours. i can't get the HV up and stable, so i'm turning the beam over to them. maybe the time won't be totally wasted then.



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