201309 R1ProgressRep

09/04/13

Replaced 10 clean room filters

Tasks remaining:

1. Measure all Field and Sense wire tensions prior to potting
2. pot S2 & S3
3. install Windows on S2 & S3
4. install HVBs & STBs onto S2 & S3
5. burn in S2 & S3
6. finish Q&A on all chambers

David Coneff is managing two student workers and plans to finish the above remaining tasks before Jan 2014 as a part time worker, their work schedule is given below.

Mon	Tues	Wed	Thurs	Fri	Sat	Sun
1-5pm		1-5pm		1-5pm	11am-5pm

9/20/13

Q&A tasks remaining

1. discovered current draw beyond 20 uA when Sector 1 HV_SL1 board 7 voltage is raising to 500 volts. need to debug

The board drags a high current, all the boots were removed and the current is 15 uA for field, 12 uA for guard, and 1 um for sense as the applied voltage on them is 35V, 10V,50V successively.

The current disappears as all the guard jumpers (GW1P2 and GW2P2)are removed, or removing the field jumper FW13.Resistance is measured between FW13 and GW2P2 and it value is 2.8 Mohm, and the same for between GW1P2 and FW1. Since SL2 in S5 has not an applied voltage, it can be a reference. SL2 HV board (course) has open line resistance between all the jumpers that were measured previously.

1. replaced Sector 1 HV_SL1 board 4 due to a broken bus pin
2. continue burning in Sector 5
3. finish taking scope pictures of sense wire output on Sector 5
4. continue debugging TDC input cables

CLAS12_R1_Progress_Reports#September_2013