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User name arvieux
Log entry time 23:12:40 on May 06, 2004
Entry number 84327
Followups:
keyword=RC Daily Report 5-6 May
Run Coordinator Daily Report for 5 May Owl to 6 May Swing
Summary
Doing further tests with Hall A (at 90 uA), Hall B and Hall C alternating
40 uA and 0 uA (leakage from Hall A+B) as explained below
Completed detector studies with SOS (08:00-17:00)
GMS is still off.
Significant News
During Wednesday Swing and Thursday Owl, we have done
stability
tests of the leakage with Hall A+B on, by alternating 40
uA runs with 0 uA (leakage)
runs in Hall C, every hour (with IHWP IN and
OUT).
Detector tests for future experiments have been done during Day
Shiftt.
At 11:00, we had a meeting with injector and accelerator experts to
draw a test plan for further leakage studies without Hall B. We came to
the conclusion
that we needed several periods without Hall A running:
-
one period of 4 hours to measure Hall B leakage with a high
precision
by inducing large beam asymmetry using thr RWP (Rotatable Wave Plate
-
another period of 4 hours for studying the sensivity of the Hall
B leakage into Hall C ae`s a function of Hal B operating parameters
(laser power, slit opening...)
-
a long period of 3-4 shifts to validate with good statistics the method
which consists in measuring the asymmetry in the time bins outside the
physical region to
correct under the elastic peak.
At 15:30, we have had a meeting with Larry Cardman and Dennis
Skopic
and we got approved for the first 2 tests (8 hours in
total)
to
be done during
Friday Owl (00:00-08:00)
At 17:00 Hall C was closed and we started putting things back
to normal running conditions.
At 18:25, SMS fast dumped. Kaz and Damon were called but they
experienced difficulties with one analog input modules
reading the flow and temperature of the cooling water. At the time
of this writing, they seem to have fixed the problem and the
magnet is being filled up.
At 22:45, SMS quenched again :-(
At this moment (23:00) I have no idea when we'll be able to
start our tests.
Hall A will have people on shift during the night until we are
ready to take data and we ask them to switch off (thanks to them).
Target boiling studies could be done on Friday
after
the leakage studies.
Completion of thresholds studies with IHWP=OUT
will
be done during Friday Swing-Saturday Owl (2 shifts).
Short term Plans
-
When SMS comes back and we are ready to take data,
follow
the detailed leakage studies run plan. of Paul King printed
version
on the Shift Leader desk.
An electronic version can be downloaded from http://www.jlab.org/~arvieux/leakage.v2.pdf
-
After the leakage tests are done (8h in total), do the target boiling
program.
Detailed run plan can be found at http://www.jlab.org/~smithg/g0/boiling_test.html
-
Resume threshold studies with IHWP OUT after detector
tests are completed Thu around 16:00.
LH2 target, standard running conditions except thresholds.
Due to differences in FR and NA splitters the thresholds of the FrAm
detectors have to be higher than the FR thresholds. A new Reference file
has
been created with FR thresholds at 100 mV and FrAm thresholds at 140
mV (Reference_FiB_Buddy_Fr100mV_FrAm140mV
). So for the thresholds studies:
- load
Reference_FiB_Buddy_Fr100mV_FrAm140mV
-set NA threshold to 14
-
Run 2 shifts at 40 uA with IHWP = OUT. That
should bring us to Saturday morning.
-
When reverting to standard running , don't
forget:
- to load the Reference_FiB_Buddy
- to set the NA thresholds to 7
SETTINGS TO BE USED WHEN RUNNING WITH NO CURRENT IN HALL
C
-
Lumi gain has to be multiplied by 1000, this being obtained by
gaining
a
factor 100 using an increase in HV and another factor of
10
by
changing the gain of the lumi amplifiers. For that:
- Switch from standard lumi HV file
HV.2004-02-19.lumi_halo_on.hvcto
HV.lumi_highhigh_on.hvc
- Change the 6 lumi amplifier settings in Electronics Shack
upstairs
(if you don't know how to do,ask Mark Pitt or Jianglai or
the
RC).
-
change BCM 1 and BCM gains from 3==>5 in rack CH03B11 in Hall C
electronics room. These will most likely not work as sensivity
is 1 uA only for these settings but it does not hurt.
DON'T FORGET TO SET THESE BACK TO NORMAL
CONDITION
WHEN RUNNING AT HIGH CURRENT.
Longer term Plan
-
Transverse running on
Monday-Tuesday-Wednesday
if no other business.
-
Next week (tentatively on Tue or Wed): one full Day shift
will
be devoted again to SOS tests.
-
If agreed by JLab management we may have more periods of
beam leakage studies with Hall A and/or Hall B OFF.
Detailed
run plans will
be given in due time.
Concerns