Notes from Local Meeting on Jan. 29, 2004
In attendance: David Armstrong, Hachemi Benaoum, Rob Feuerbach, Tim
Holmstrom, Lisa Kaufman, Bob Michaels, Bryan Moffit, Kent Paschke,
Ryan Snyder,
Septum Status - Tim
- Recent control problems. Readback appeared frozen.
Experts are still working on it.
- Cooling is still a big issue (Left Septum cooling every
12 hours)
- Right septum heats up when running with waterfall target, so it was necessary to run at 60 uA instead of 100 uA with this target
Hall Status
- Recent problem with vacuum leak on Left HRS Q3.
Probably will take several weeks to replace.
There
is some rumor/speculation (propagation continued here) of
the possible effects on the HAPPEX start date, including a
scenario with an earlier start of HAPPEX.
- Also some rumor/speculation about G0 gaining an
additional 39 calendar days (15 or so PAC days) of
production running, to make up for inefficiencies in beam
delivery and the need for more background studies than
originally anticipated.
Lumi Hardware - Hachemi
- Shows how the helium purge line will connect to the Lumi
PMT.
-
May use a scintillator to look at test pulses from the
PMT.
This arrangement may also be useful for Bryan's
Signal Width-HAPPEX ADC study
- Light guides have not arrived yet.
- Here's a figure showing the lumi construction (light_guide_PMT.eps).
Lumi Analysis - Bryan
- Lumi Normalized Asymmetry RMS on the H20
target is nearly 14000 ppm.
Could be boiling... could
be variation in target thickness due to the unconstrained
nature of the target.
- BCM Asymmetry RMS appears to have gotten smaller (~700ppm)
- For Carbon target, Normalized asymmetry RMS is around
200ppm
Will check to see if this agrees with Riad's
estimate.
- Will also trying running with the Prototype lumi, to
find out:
- Why one back lumi has a smaller RMS than the other.
- Why regression slopes (vs bpm4bx) are the same sign
in both back lumis (they're on opposite sides of the
beam pipe).
GDH Analysis - Ryan
- Finished with spreadsheet documenting each run.
- Learning about submitting jobs on the computing farm
Laser Room - Lisa
- Laser Room AC is back in service
- Pockels cells are hygroscopic, therefore it is necessary to be careful to protect windowless cells from a humid environment (e.g. laser room w/ broken AC)
- We are ordering 2 new cells from Cleveland Crystals this week
PAN
- Bryan wants to separate the Dacnoise and Pedestal
subtraction from the ADC calibration variables in the ROOT
Tree.
This will be helpful for BCM/BPM/Lumi Calibrations.
- Will check with Rich to see if he has any objections
before the change is made
Bryan Moffit
Last modified: Thu Jan 29 16:41:14 EST 2004