CCR optimized the slits achieving BQM normalized rates of:
U=160 D=70 L=170 R=70
with slit settings of:
L=-7, R=10, T=1, B=-10
This was the first shift this run with ABS. Things ran fine for the first
hour and we took data with the 1/4 wave plate in for +1 target vector pol
(run 266) and then for -1 target vector pol (run 267) also with the 1/4
wave plate in. Then things started to heat up! In particular the ABS
nozzle temp started rising. I called VZ then Genya and by the time we
spoke the nozzle temp had gone from 75K to 105K. Skimmer pressure was up
in 1E-4 Torr regime (i.e. 4 orders of magnitude off the mark)
With Genya's instruction I did 4 things:
1) had CCR turn off BLAST coils (to read IGs)
2) shut off the gas (not touching set points)
3) shut valve 11
4) shut off RF power
(before doing this I set all detector (incl WCs) HV crates to standby)
Then Genya said to call Ernie. With Ernie on the phone talking me
through things I did the following:
1) Went to the mezzanine and reported on various readings from various
gauges.
2) I then disconnected the exhaust line from roughing pump 3.
(it sounds like the roughing pump was backing up)
3) On the mezzanine rack I opened valve 16 (really vlv11) and then shut it
again.
4) Upon returning to the counting bay I went through the appropriate
sequence of valves to get things flowing again.
5) Turned on the gas (hydrogen and oxygen) - but here the readout did not
return to the previous values and I had to use the setpoint field.
I set hydrogen to 60 sccm and oxygen to .05 sccm(later changed to .12 per
Genya)
6) I turned RF power back on and used the ATK controller to do the
required impedance matching for teh dissociator using the smith chart
display.
So with Ernie and Genya's help things were working again. I asked CCR for
the magnet again (without it there is no polarized target!) and then
noticed that the left WC hv crate had tripped. I went to the D-tunnel and
noticed that it in fact had not tripped but was not responding to the WC
hv daemon so I reset it.(Doug later informed me that I had skipped a WC hv
command) With all crates in stby CCR injected and I
started running again. Then I
lost the left TOF hv crate and the hvDaemon would not respond. I
stopped the run and restarted the daemon. I had to do this a few more
times during the shift - so this is why we don't have many 50K/100K runs,
Also, CCR informed me that the way the chime works is to change 1/4-wave
plate position at a stored beam cutoff (44mA) [not just when we do a
fill].
When things started calming down I started crunching ntuples using spuds
2,3,5,6,7 simultaneously. began crunching runs 266,267,268,269,270
Unfortunately, due to the circumstances I did not get ot analyze anything
but at about 2350 the ntuples finished crunching so I wrote the scaler
charge: beam gated, ungated, and epics values in the logbook.
Pete
----------------------------------------------
Pete Karpius
Graduate Research Assistant
Nuclear Physics Group
University of New Hampshire
phone: (603)862-1220
FAX: (603)862-2998
email: karpiusp@einstein.unh.edu
http://pubpages.unh.edu/~pkarpius/homepage.htm
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