NEW HV cable for BIAS installed earlier this week.

Wednesday, June 28, 2017, 16:42: BIAS at 20 kV

Wednesday, June 28, 2017, 16:46: BIAS at 30 kV, EZL at 15 kV

Wednesday, June 28, 2017, 17:00: BIAS at 35 kV, EZL at 17.5 kV

The voltage response on TBHT and TGHT changed as the target was heated up. This was later determined to be due to target shorting to heat shield and the grounding of the power supplies being achieved at the HV pedestal in the target hall and not in the HV enclosure as is done online. When this was changed, the target operated normally again.

John Chow and I installed new TCS HV cable and feed through with their mounting panel back to TCS Faraday cage this Tuesday. ECO-4269 has been issued for the new cable feed through and mounting panel.

 John Chow configured TCS to cathode bias mode (IRH1538). The anode P/S is in positive mode.

Prepare for TM4 move tomorrow morning.

The target hall has been locked-out as per Document-70039.

Forced IG1, IG1S and IG2 to switch on BIAS power supply

Wednesday, July 12, 2017, 11:53: 70 kV at 0.16 mA

2 sparks observed shortly after 70 kV was reached

Wednesday, July 12, 2017, 12:59: No sparks for the last hour.

BIAS power supply off. Forces removed.

 TM#3 has been moved from the north east silo to the conditioning station.

50 kV stable with less than 1 spark/h during the weekend by RIB obs.

Today 57 kV reached, but observed sparking on the resistors of the new HV cable. The cable will be removed to take out the resistors, before reinstalling it.

The target hall was locked out, but has now been reopened. This was to avoid sparking to the HV cover.

Anders Mjos wrote:

50 kV stable with less than 1 spark/h during the weekend by RIB obs. Today 57 kV reached, but observed sparking on the resistors of the new HV cable. The cable will be removed to take out the resistors, before reinstalling it. The target hall was locked out, but has now been reopened. This was to avoid sparking to the HV cover.

 EL was brought to 27.5kV.

Conditioning continues today with resistors removed from the HV cable

Tuesday, July 18, 2017, 16:53: BIAS / EZL 50 / 25 kV - no sparks

 Tuesday, July 18, 2017, 16:56: BIAS / EZL 55 / 27.5 kV - one spark

TM3 remained at 55 kV over night. Turbo pumps tripped twice and was restarted and HV recovered by RIB ops. Last recovery brought EZL to 16 kV (not 27.5 kV)

About 25 sparks over 15 h. No sparks for the last 3 h

Wednesday, July 19, 2017, 08:12: EZL to 27.5 kV

Wednesday, July 19, 2017, 08:38: BIAS to 57 kV

Wednesday, July 19, 2017, 08:46: BIAS to 57.5 kV

Wednesday, July 19, 2017, 09:05: BIAS to 59 kV

Wednesday, July 19, 2017, 09:19: BIAS to 60 kV

Wednesday, July 19, 2017, 09:28: EZL to 30 kV

Wednesday, July 19, 2017, 12:25: Heavy sparking. Lowered BIAS to 30 kV

Wednesday, July 19, 2017, 12:37: Increased BIAS again towards 50 kV, but heavy sparking again between 45 and 50 kV. Lowered back to 30 kV

Wednesday, July 19, 2017, 12:40: BIAS at 46 kV

Wednesday, July 19, 2017, 12:42: BIAS at 47 kV

Wednesday, July 19, 2017, 12:44: BIAS at 48 kV

Wednesday, July 19, 2017, 12:48: BIAS at 50 kV

Wednesday, July 19, 2017, 14:50: BIAS at 55 kV after ~2h without sparking at 50 kV

Wednesday, July 19, 2017, 15:12: Sparking. Lowered to 40 kV

Wednesday, July 19, 2017, 16:39: BIAS at 55 kV

Friday, July 21, 2017

Observed top of module inside target hall during HV sparks using crane cameras. No sparks observed, but some faint sound could be heard. Module still sparks at 60 and 55 kV. Have to lower to 40 kV to stop sparking.

Friday, July 21, 2017, 13:25: BIAS / EZL at 50 / 25 kV for without sparking for the last 90 min

 TM#3 has been moved back to the NE silo from the conditioning station.

 Thursday, August 03, 2017, 17:08: Restarting vacuum and water system

 The BIAS voltage was brought up to 70 kV today and held there for 1h. No sparking observed.

 TM#4 with UC#21 has been moved from the south hot cell to the conditioning station.

TM4 HS line leak checks are done, at SHC and TCS. SHC: Helium spray. TCS: Helium  pressurize 70psi.  LD base LR 0.0 X E-9 atm.cc/sec.  No leak has been found on both leak checks. 

TM4 has been connected at TCS. TCS water system has been started for TM4. TM4 and TCS vacuum pumping down is good so far.

Argon vent and disconnect TM4 at TCS.

 TM#3 has been moved from the north east silo to the conditioning station.

TM3 is located at TCS and it is pumping down now. TCS water system has been started.  All TCS water lines for TM3 module internal cooling are bypassed and looped at TCS top ground plate. Water only supply to TCS high  current conductors.

Preparing vent the TCS/TM3. We will remove TM3 service tray cover plate  after venting.

TM3 service tray cover plate has been removed. It is bagged and placed to TH b2 level south wall beside the silo.