High Voltage Turn On Procedure
In the GLAST installation at T9, several HV channels are connected to scintillators and cerenkov detectors placed in the cave, that are used to provide the trigger to the CU and the tagger and to monitor the beam rate and position.
HV channels are remotely controlled from the T9C barrack, through 3 HV CAEN power supplis located in the NIM crates. Details of the connections are given in the table below.
HV is an hazard for people working in the area, so people should be aware of the risk. Yellow stickers are attached in proximity of HV channels so that they are easy to identify. A safe turn-on procedure must be followed when switching on the voltage on the detectors.
Procedure
Closed are and beam on case: when the area is closed and the beam is on nobody is in the area, therefore HV can be switched on w/o precautions
Supervised access case: it is mandatory to verify that the people in the cave are aware that HV is being switched on; enter the area with your badge and warn the people inside; identify a responsible in the area that should warn anybody accessing the area while HV is being switched on; exit the area and switch HV on
Free access case: no access control is enforced; enter the area and warn the people inside of HV operations; identify a responsible that will warn anybody accessing the area while HV is being switched on; exit the area and switch HV on
HV Connections
HV module |
Channel |
Detector |
Voltage |
Polarity |
|---|---|---|---|---|
1 |
0 |
S0 |
1900 |
- |
1 |
1 |
S1 |
1750 |
- |
1 |
2 |
S2 |
1700 |
- |
1 |
3 |
Sh |
1900 |
- |
2 |
0 |
C1 |
2100 |
- |
2 |
1 |
C2 |
2100 |
- |
2 |
2 |
Pb |
1500 |
- |
2 |
3 |
S3 |
1750 |
- |
3 |
0 |
S4 |
1750 |
+ |
3 |
1 |
NaI Forw |
900 |
+ |
3 |
2 |
NaI Back |
900 |
+ |
3 |
3 |
|
|
|