Make New Entry, Make Followup Entry
User name R. Michaels
Log entry time 00:59:29 on March26,2014
Entry number 387566
keyword=BPM pedestal calibrationWe did some pulser runs with no beam to check BPM pedestals,
since Luke fixed the noise problem on the L-HRS today. He fixed it
by relocating the offset/attenuator boards. The speculation is that
there is a switching power supply on the 2nd level which caused the noise.
Runs 1241 and 20255 are with forced gain=0 and T8 trigger
Runs 1242 and 20256 are with autogain and T8 trigger
Runs 1243 and 20257 are returned to cosmics.
The pedestals are all around 3500 with RMS of about 10. Typical ADC spectra
in fig 1 and 2.
Pedestals for channels 1-8 (in order they are plugged in) are as follows. I'll put
these into the BPM database
L-HRS
3708, 3534, 3483, 3475, 3456, 3393, 3401, 3278
R-HRS
3510, 3505, 3579, 3662, 3563, 3462, 3330, 3546
The raster pick-off also has pedestals of around this size and width but
I don't think these get used by the software.
FIGURE 1
FIGURE 2
