User name J. Singh
Log entry time 04:28:42 on October25,2005
Entry number 157945
Followups:
- 157967 10/25/05 09:29 R. Michaels beamline HV issues
- 158585 10/31/05 07:28 E. Cisbani LeCroy Beamline HV Alarm
at 0411, the Beamline HV alarm went off. at first the LeCroy Beamline medm display looked ok, all the numbers were green. then after about 30 secs, three of the HV were red and the box next to the main HV ON/OFF button turned red and then grey. see fig 1. one of the red HV was for the Compton. we checked the compton stripchart and the electron & coincidence rates had dropped to zero w/o a beam trip. this gave us more evidence that something really had tripped off. in response, we stopped the compton run 12497. then we pressed the HV/OFF button in the top left corner, waited a few seconds, and then pressed the HV/ON button. the button in the top left corner turned green and the three HVs that had been red started to ramp back up. within a few seconds that HVs were set and everything was green. see fig 2. the alarm stopped; so, we started the next compton run 12498. we checked the read values with the set values for the Beamline HV and they all matched. we were back to production by 0417.
FIGURE 1
FIGURE 2
