Filled to 24.9 in

Electrical check of TM#2 with ZrC #7 installed

Hello all,

TM2's first performance in the Conditioning Station with the new source tray was not great, with sparking and HV degradation beginning to occur at 30kV:
https://elog.triumf.ca/TIS/RH-ISAC/1039

This is perplexing, because the module without the source tray performed well at the TCS:
https://elog.triumf.ca/TIS/RH-ISAC/829

AND the new source tray performed well at the test stand (i.e. not inside the module):
https://elog.triumf.ca/TIS/Test-Stand/447

Upon inspection back at the Hot Cell last week after the failure, David Wang was observant enough to notice that one of the steerer coax wires (ground plane) was essentially touching one of the FEBIAD gas lines (HV plane) in the new source tray installation (photo attached).  Closer inspection by a group consisting of Anders, Alex, and myself revealed some apparent tracking and damage to the wire sheath.
https://elog.triumf.ca/TIS/RH-ISAC/1045

We believed at this point that the bad HV performance of TM2 was due to this problem.  The wires were originally arranged loose as it was believed it would be easier to install them in the Hot Cell this way.  However, it turned out to be a bad decision, as the wires at ground ended up becoming stray and touching the HV surface.

To correct the problem, the old wires were removed, and a new steere wire bundle was made using a PEEK material sheath.  This new sheath bundle was installed over the last day or so.  The penning gauge wire was kept separate from the steerer wire bundle.  You can see the new wire bundle and penning gauge wire in the attached photo, now with a healthy clearance to the FEBIAD gas lines.

Chad has been instructed to re-install the Einzel lens wire, install the new ZrC target, and replace the containment box in preparation for transport back to the TCS for another HV test.  If anybody would like to see the source tray today before ~3pm, I have asked Chad to wait for my final OK to put the containment box back on the module.

I apologize for this problem.  We are hopeful the solution we have installed will improve the HV performance.  Much work over the last 2+ years was put into building and installing this source tray by many contributors inside and outside of Remote Handling, and we want this module to succeed more than anybody!

Thanks and best regards,

Grant

Yesterday TM2 was inspected in the SHC. Spark marks were found both on the steerer wires and on the ANODE wire. The steerer wires (GND)  were touching the gas lines (60kV). This is likely the cause of the sparking observed at the Conditioning Station (e-log).

Photos are available on DocuShare

 Weekly update target hall schedule.See attachment 1,2

Spring and summer run is close to the end. This will be the last update on this old schedule. See attachment3,4.    A new schedule for TH activities after mini shut down will be posted next time.

TM#2 electrical check at the conditioning station. All pumps were off but the module was not vented.

TM#2 is now in the south hot cell.

TM2 was disconnected at CS. Travis and I did  electrical check before the venting. After,The module was vented and moved to SHC. The moving is smooth.

During the TM2 HV test at CS, It failed. In order to confirm there is no any water leak inside the module after the heaters and beam extraction test, I disconnected all the water lines on the TM2, and purged the water lines with pressure air. Leak detector was reconnected back to the TM2 service cap, and all water lines are pressurized with 80psi helium again each for 2 minutes.No any leak had been found during the test. All the water lines are still perfectly sealed. Also, I checked all the vacuum to air seals on the top of the module.They are good either.  Anders used the RGA  tracking the helium during the test. No leak.

TGHT, TBHT, ANODE and COIL power tested (some amps/volts)

Monday, August 17, 2015, 10:43: BIAS/EL/EE to 15/7.5/1.5 kV

Monday, August 17, 2015, 10:45 : COIL 20A, ANODE 200V

Keiko fixed the auto-ramping program and access rights to it.

Monday, August 17, 2015, 13:06: Auto-ramping at 2/1 A/min. Good/bad vacuum at 6E-6 and 8E-6 T

Monday, August 17, 2015, 13:24 : ANODE current limit set incorrectly. Corrected and 200V (9 mA)

Monday, August 17, 2015, 15:28: COIL to 50 A

Monday, August 17, 2015, 15:43: Reduced ANODE to 100 V

Monday, August 17, 2015, 16:56 : Increased EL to 8.3 kV to increase FC current.

Monday, August 17, 2015, 17:04 : FC0 current at 1.5E-8 A

Beam ionized and accelerated on the new TM2 source tray

Monday, August 17, 2015, 17:12 : TGHT / TBHT at 500 / 250 A. Will leave over night to outgas. ISAC ops are monitoring the source.

Tuesday, August 18, 2015, 08:07: Everything stable overnight. Continue ramping heaters.

Tuesday, August 18, 2015, 08:48: TBHT voltage limited by EPICS (hardcoded) at 273 A.

TGHT/TBHT at 600 / 273 A 

Tuesday, August 18, 2015, 09:52: Adjusted COIL current down to 0 and back up. Response seen on FC0.

Tuesday, August 18, 2015, 22:29 : Starting cool down.

 Wednesday, August 19, 2015, 08:26: Source and HV off. EE configured to conditioning mode. RGA off.

Wednesday, August 19, 2015, 08:42: BIAS/EL at 15 / 7.5 kV. PNG1 at 3.5E-6 T, IG1 at 3.9E-7 T

Wednesday, August 19, 2015, 08:53: BIAS/EL 20 / 10 kV. 2 sparks.

Wednesday, August 19, 2015, 09:54: BIAS/EL 30 / 15 kV. Some sparking around 28 kV required BIAS voltage to be reduced momentarily. 

Wednesday, August 19, 2015, 10:04: Sparking at 30 kV. Reduced BIAS to 13 kV to get spar rate to less than 10/min

Wednesday, August 19, 2015, 10:19 : BIAS current limiting. Switch off BIAS and EL

Wednesday, August 19, 2015, 12:04: Water off for purging and leak test.

Wednesday, August 19, 2015, 12:52: Vacuum response observed while David was working on purging the water lines. This turned out to be when the valve to the leak detector was opened.

I finished the rest TM2 connections to CS, and started CS cooling package. Everything works fine so far.

TM2 has been moved to CS. All turbo-pumps have been started. The pumping down is good so far.  I connected the leak detector to service cap, and finished the leak check today.  The LD base LR:0.0Xe-9atm.cc/sec. 80psi helium were applied to coil1, coil 2. HS and window circuits, each for 2minutes. No any response has been found on LD. So all water lines are leak tight now. I also sprayed   helium to top service cap checking all air to   vacuum seals. They are all good either. But, The new installed PGN1 does not work. Other thing need to mention is The TP2 is running at 2.45A which is 1A higher comparing to TP1. It need to be monitored to see if we have to replace it or not. The high current cables and water lines will be connected tomorrow morning.

TM#2 with the dummy target has been moved to the conditioning station.

As previously mentioned, dump target installed with new mounting and high current fasteners.

Leak Check complete and ready to move to CS at 1:30

Electrical check of TM2 without target after that widget has installed, electrical check with the shunts on, electrical check with the dummy target installed.

Tuesday, August 11,  insulator ITA6272 was installed onto the "pin x" line (unused plasma electrode) and tested; it seems to have successfully eliminated the shorts on that line.

Wednesday, August 12  "shunts" installed on tube heater and oven circuit and electrically  tested.

Thursday , August 13, dummy target installed.

The containment box was taken off TM2 in preparation for installation of a new coil line isolator.

ITA6272 and ITA6273 have been received from the Scintillator Shop.  ITA6274 should be ready by the end of today.

Weekly update target hall schedule and activities. See attachment 1,2

Update and extend Target Hall schedule to Sep 08.  See attachment 3,4

TM#2 is now in the south hot cell

All targets but one ( SiC#31 went in last week) have been measured or assayed. See attached PDF for the details.