Difference between revisions of "Compton Calorimeter Shift"

Revision as of 12:06, 28 November 2022

Compton Calorimeter

The compton calorimeter (CompCal) is an array of 12x12 PWO modules. Light from each module is detected using Hamamatsu R4125 photomultiplier tube, which is operated at the typical HV of 800 V.

Routine operation

The shift workers will need to monitor the CompCal performance using the CSS monitoring GUIs described below. The following parameters have to be checked during routine operation of the CompCal detector:

• occupancy plots discrepancies between the detector occupancy plot and the reference histogram such as 'holes' in the occupancy plot, have to be recorded in the log file and the detector experts listed below have to be notified.
• high voltages in the case of problems with HVs on the detector, an alarm should sound; the shift crew can turn ON and OFF HVs using the HV GUI. If the problem persists the expert should be called. Any operations with HVs have to be recorded in the log file and the detector expert should be notified. The HV parameters, such as voltage settings and trip currents cannot be changed by the shift worker.

CompCal EPICS GUI Screens

The crew should set the voltage on the PMT using the GUI interface (see instructions below). If the problem persists the expert should be called.

Expert personnel

The individuals responsible for checking that the CCAL is ready to take data and setting its operating parameters are shown in following table. Problems with normal operation of the CCAL should be referred to those individuals and any changes to their settings must be approved by them. Additional experts may be trained by the system owner and their name and date added to this table.