LD base leak rate, 0.0Xe-9atm.cc/sec. Helium pressure, 70psi. 5 minutes each circuit. No response on all water line except containment box window which has a VCR leak issue now. Window line leak rate, 2.3Xe-4 atm.cc/sec.

TM4 water lines helium pressure test was done yesterday at ITE. All water lines were air purged one day ahead  for the test. No leak  has been found on TM4 waterlines during the test. See attachment for detail

TM4 waterlines have been disconnected and purged in ITE. The TM4 vacuum system is still in operation.

TM4 was removed from NHC to S_W silo yesterday.  The remove is smooth and successful.

TM4 was disconnected in ITE yesterday. See attachment for checklist.

TM4 was disconnected at ITE this morning. It was moved to SHC  after. No alpha alarm issue has been happened during and after move. The ventilation pumping down procedure on ITE was fulfilled during the move.

TM4 was disconnected at ITE this morning. It was moved to SHC  after. No alpha alarm issue has been happened during and after move. The ventilation pumping down procedure on ITE was fulfilled during the move.

TM4 vacuum has been connected in TCS. All vacuum pumps were started yesterday. The pumping down of TM4 and TCS are good so far.

All turbo pumps are started yesterday. The pumping down is good over night.

Turbo -pumps are started . The vacuum looks good so far.

Cables were disconnected for steers in containment box. The Megga measurement (500V) result from the top of the module:

Left to right: OL, left to top OL,  left to bottom OL, right to top OL, right to bottom OL,  Top to bottom OL. And all of them to ground are OL.  No short on cables from module top to steers itself. The short should be inside the steers. It will be confirmed with directly test on steers.  

TM4 Steers 4 pin feedthrough CF flange is replaced due an inside feed through insulator broken. CF 25 cooper seal is replaced with a new one as well. Travis did anelectrical check. after replacement. Everything looks fine.

Note only a megger check was performed on the affected steering lines. Open load was measured on all lines. (Travis Cave)

Left (short) is switched with bottom. So on module:

Frank and I removed the panel, disconnected the "Left"cable  inside panel,  and checked  cable to ground resistance. "Left "is dead short to ground on ohmmeter check still. So the short could be on cable or inside source tray.  Further investigation is planned to confirm the short  location.

 Friday, April 30, 2021, 14:06

Anders and Luca

Resistance measurements on each electrical feedthroughs (A,B,C,D,E,I,P,Q,R,U,60kV,ground) taken with no target or no short attached to the module. Results as expected:

P-Q = 6.439 mOhm

R-U = 6.019 mOhm

All other combinations = Open Loop

New steerer cables are installed in TM4. Cables are properly routed in containment box and service cap top. After job, TP2 is installed back onto module top.

New source tray was installed on TM4 yesterday. LD was used to pump down all water lines. Tube heater +D circuit has a big leak  around water block area. At base LR5.5 XE-5 atm.cc/sec, base pressure 170 mtorr, When Chad  moved this helium probe close to  water block area, The leak rate on LD went to maximum level right away. When the probe was moved out of water block area, the LR went back to base level. The test repeated again with same result. Also, Before helium spray test, I applied 80 psi air into the circuit. The air pressure can not be held in the circuit. The pressure drop on the line is quick. This shows a big leak on  D line as well. The rest water lines are fine. I pumped all of them down to LD bottom scale without problem. Chad and I helium sprayed window and MSP water blocks. No leak has been found.  The only line we have problem is the D line.

D line is still leak after repair and installation. We suspected the c-seals issue on this module. So, all water lines have been sprayed with helium for leak check.  Found "B" line target oven negative  is also leak. The rest line are good on helium spray leak check.  The further investigate on thi issue is taken place now.

TM4 was successfully moved from the South Hot Cell to the South-West Silo remotely by Grant Minor, with help from David Wang and Don Jackson.  The move was without problems.  See ISAC Work Permit 2012-12-04-1.

 TM4 was moved from conditioning station to south hot cell in preparation for wiring replacement. No target.

Tm4 has been moved from SHc to TCS without containment box. It is a new source tray on TM4.  A layer of plastic sheet was put on TH floor on module pass route during the move.

 I did a leak check again on TM4 today. This time, the leak detector pump to the bottom on both base pressure(0.0xE-4 torr) and base leak rate(0.0xE-9 atm.cc/sec). All high vacuum gauges on TM4 and conditioning station at -6torr range.IG1 is 3.3-6torr,PNG5(top of service cap)is 6.5-6 torr, and the PNG4(bottom of the vessel )is 8.7-6torr. For air to vacuum leak checking, I checked the panel we moved last week on service cap by spraying helium around the panel. There is no any response on leak detector. The panel is leak tight. Also I sprayed helium around the tube heater (+) water cap and blue nylon stand. They are also leak tight. Then, I put 80 psi pressure air to the “D” circuit first. With 80 psi pressure air for 5 minutes, the leak detector has no any response on it. Also all high vacuum gauges stayed at same level .Then I checked it with 80 psi pressure helium for 3 minutes. The leak detector has a response on leak rate with pressure helium same as last time. It climbed from the 0.0xE-9 atm. cc/sec quickly to high -8 range then slow down. The leak rate finally climbed to 2.0 X E-7 atm.cc/sec this time. There is no base pressure change on leak detector. All high vacuum gauge readings no change during the test time. There is a small helium leak at 80 psi pressure test on “D” circuit. But we can not locate it at this stage. Also I don’t want to disturb this circuit any more before the febiad run since this time I saw a little bit increase on leak rate comparing to last time when I checked it. If we really like to find this small helium leak, I would suggest we do it after the febiad run.    Thank you.