HEC Endcap C ATLAS Pit HEC 1 HV

HEC Endcap C ATLAS Pit: HEC 1 HV Status 3 3 1 1 Number of problems section 1 1 3 2 3 2 1 1 x x 1 1 Number of Problems section 2 9/17/2020 1 Endcap C ATLAS Pit July 2007 1

Study f-wedges 9 -12 Presently up to 500 A only! HEC Endcap C ATLAS Pit: HEC 2 HV Status 4 2 2 OK! 2@1200 4 3 1@1200 3 2 1 4 4 1 OK! 1 1 2 Number of problems section 3 1200 V corresponds to ~ 85% of signal! 3 1 1 OK! 1 1@1200 1 1 x Number of Problems section 4 1 9/17/2020 Endcap C ATLAS Pit July 2007 2

HEC Endcap C ATLAS Pit: HEC 1 HV Status 1 2 1 6 4 2 4 Number of old problems 5 1 x x 1 1 1 Number of new problems 9/17/2020 Endcap C ATLAS Pit July 2007 3

HEC Endcap C ATLAS Pit: HEC 2 HV Status 1 1 3 Number of old problems 4 8 6 3 2 2 1 1 1 x 1 Number of new problems 9/17/2020 Endcap C ATLAS Pit July 2007 4

HEC Endcap C ATLAS Pit: HV Status HV Probs. 9/17/2020 Endcap C ATLAS Pit July 2007 5

HEC Endcap C ATLAS Pit: We have 30 problems (4 old, where 1 is disconnected) in HEC 1 and 40 problems (8 old) in HEC 2; most are shorts with a resistivity of few MΩ typically; Cables and filterbox checked OK; High resistance means that most likely electrodes are involved; Problems cluster at top, density per gap dropping from HEC 2 to HEC 1 somewhat; Need to run with (larger) currents; In critical region we can use ISEG modules up to 500 μA; assuming we are running up to 400 μA, we can ramp up 40 channles up to 1500 V (instead of 1800 V); Additional 18 channels have to be operated with hospital modules up to 1 m. A; 9/17/2020 Endcap C ATLAS Pit July 2007 6

HEC Endcap C ATLAS Pit: front If we stick to the normal operation mode wherever possible, i. e. disconnect up to 2 HV lines per section and correct signal by factor 2, we need to operate following sections with currents: sections 6 2 10 1, 2 11 1 12 1 7 3 9 3, 4 10 3, 4 11 3, 4 rear Total 9/17/2020 Endcap C ATLAS Pit July 2007 12 7