S117 meeting, 4.7.95
DAQ
Pass 1 has finished, the pedestals will be corrected in some days. The changing
pedestals are probably coming from a changing offset since they are measured
in a special pedestal event where no external signal goes in the QDC.
In GSI and MSU hodoscopes the pedestal deviations are up to 100 channels,
for the Catania tey are rather small.
Start detector
The start detector shows an better time resolution with increasing HV. For low
count rates one can understand this (more electrons on the anode). For our high
rates, however, the resolution should be constant since the electrons on the
anode are governed by saturation effects. The time of flight shows a peak and a
background to smaller times. It remains to be cleared where this background
comes from.
TOF wall
The N_IMF vs Z_bound plot shows for large Z_bound values not going to zero
N_IMF. That's because we miss some heavy residues (JOPL) and the event is sorted
in the low Z_bound bin. Since we are plotting means and the most fragments come
with low Z_bound, there is a big effect at high Z_bound and no effect is seen at
the low Z_bound bins. To completely understand this one needs the information
from other detectors (multiplicities).
PID
Mahi checks the gate setting routines to figure out what they can do and what
not.
Calibration
The offset research (MS) is slowly going because of limited computer power
accumulating histograms for higher statistics. There was the recommendation
to use larger bin sizes and to calculate the memory consumptions before one runs
a code.
Mechanics
The alignment mount for angular measurements is finished and first measurements
are done. There are still problems with a changing view with changing focus of
the camera and the not perpendicular target rod.
Trigger documentation
The check of the trigger will be done by Claudius the following week.
Computing environment
There was full AL_TEMP0: last week and Walter wants everybody to check batch
jobs before running if there is enough disk space available.
July 4th, 1995 Carsten Schwarz,