User name R. Michaels
Log entry time 00:34:01 on July21,2005
Entry number 148817
This entry is a followup to: 148806
keyword=Qsq Scanner VDC calibration results
Results of runs 2188 to 2190 to calibrate the Qsq scanner
We plot the VDC X-Y position versus for the Qsq scanner trigger
T5 on R-arm, T6 on L-arm.
For the L-arm, there is a clear correlation and the spot moves
when its supposed to. One funny thing is it seems that what the
VDC folks call "X" the Qsq scanner folks call "Y". But now I
realize this is ok because in Qsq-scanner-speak, Y is the "long"
axis which is the dispersive axis. See fig 1.
For the R-arm, there was only one run (2189) for which the
ADC amplitude was appreciably above pedestal, as noted in a
previous halog 148806. Only in that run (2189) is there a clear
correlation to VDCs, see fig 2. I don't know what's wrong with
R-arm but the two choices are: 1) The position is on the edge
of where particles go (unlikely but I'm too tired to prove it),
or 2) The detector is flakey and "comes and goes" (my guess).