Yesterday Diagnostics group installed a temporary external limit switch to provide the in signal to the safety system.

ITW and TM2 primary and secondary vacuum vessel leak check is done. Leak detector is connected to ITW TP1. Base leak rate on leak detector is 0.0 x E-9 atm.cc/sec.   See attachment for the result.  No big issue. Two old leaks we found last year at location D and E disappeared in this check. We did Vacseal resin spray on them last year.  It looks like the Vacseal spray works .  From the result , I can see the o-ring between exit 1 module and T - flange is closing to the end of the life.  There are two small leaks on this o-ring now at A and B location. We plan to change this o-ring next winter shut down. We do vacseal spray on them this year. The big O-ring between tank vessel and T -flange looks still ok. Two small leaks are found on location F and G on this O-ring. Not much we can do on them. The leak on location C and B were sprayed with resin yesterday after leak check. They are leak free after spray on check. I will double check them. Leak on location A will be resin sprayed after TM2 is removed and ITW is under vacuum.   All TM2 internal water-cooling lines are helium pressurized (70 psi) for 5 minutes each. HS shows 2.5 X E-9atm.cc/sec leak rate. The rest lines are 0.0 X E-9 atm.cc/sec.

In past two weeks, ITW/ ITE primary vacuum back up lines and BVs in ITW/ITE pit have been leak checked.  ITW BV1 and BV2 on back up line side were leak. They are replaced with old leak free BVs.  ITE TP2 NW25 SST  flexible line right after pump were leak . It is replaced with new NW25 SST flexible line. Two leak were found on ITW side KF 50 O-rings connected to NW 50 SST flexible coupling. They were replaced with new KF50 o-rings. After job, both  stations primary back up lines in pit were leak checked .  They are good.

2013 winter shut down ITW-TM1 primary vacuum vessel, secondary vacuum vessel, and water lines leak check: connected leak detector to TP2(primary and water lines) and TP4S (secondary). base leak rate 0.0xE-9atm.cc/sec,base pressure 0.0XE-4torr. Sprayed helium to all primary vacuum seal and there is no response on leak detector. Helium pressurized all water lines(except HS) at 70psi ,3mins.Tube heat(+) no response, tube heater(-)1.6xe-9atm.cc/sec, target oven(-)5.8xe-9atm.cc/sec, target oven (+) 6.9xe-9atm.cc/sec, EE 5.7xe-9atm.cc/sec, MSP no response, window 7.5 xe-9atm.cc/sec.All water lines are water leak free.  Two leaks had been found on secondary vacuum vessel. One is on exit 1 to tank o-ring (east side, E-N corner). The leak detector got   responses from 1.4 to1.7 xe-7 atm.cc/sec scale . The test  hadbeen repeated 4-5 times and   confirmed the location   . The second one is a small leak which  is on exit 2 to tank o-ring(east side, close to E-N corner). The leak detector got  responses from 1.4 to 1.8xe-8atm.cc/sec scale. The test had been repeated 3 times and confirmed the location. As the present plan. we will replace the exit1 to tank o-ring during this year shut down time.

I let isac opp switched off ITW turbo-pumps. The argon vent valve in electrical room is opened. The ITW argon venting will be started  soon.

ITW water system maintenance is done. All working paddle wheels and coils are replaced. ITW water system polyurethane tubes are replaced as well. Two 3/8" leak small valves on return lines are replaced. 85 liters of tritium water are transferred from storage tank to B2 level holding tank. LALC water are refilled into S-tank. Restarted pump and checked system. Everything works fine now. No water leak has been found so far.  

Annual ITW water signals interlock check are done. Everything works good.

I did a ITW water signals interlock check with ISAC opp. They are checked once a year before first beam on.

2016-04-13 Same test is done on ITE also. Everything is good.

ITW water signal interlock check is done. Everything works fine. ITW 2A2 tank water signal is broken and is not ok on XT2A2  page. I will fix it next week.

ITW water signal interlock check is done. All ITW water signals including HS, EE, Coil , Ta, Tu, MSP, C-window, HVC1, HVC2, 2A-dump, 2A -shielding plug, 2A-tank, 2A-window, and 2A-collimator are checked. All  water signal interlock work fine.

A water leak was found on a fitting connecting ITW dump return line pressure gauge on top of exit module. TM tank flange, o-ring slot and o-ring were contaminated by water and water rust. Frank and I cleaned the flange and o-ring slot . We changed a new TM tank o-ring, vacuumed around other 3 module flanges. The leak fittings with pressure gauges were removed . I put a blind cap on removed fitting spot.. Water are switched back to ITW. No leak on blind cap.

ITW water interlock check is finished. Everything is good.

ITW water flow wheels and coils are replaced. Wheels and coils on Oven, Tube, HS, EE, MSP, Febiad coil, containment box window, dump,dump plug, 2A window, and tank return circuits are replaced with new parts.

Frank and I finished ITW and TM2 leak check. TM2 internal water-cooling lines are leak free. They passed 70 psi helium pressure test. We found some small leaks on ITW primary and secondary vacuum vessel. I list them here:

1. Exit module 2 service cap top plate to cap body O-ring at SW corner. Leak rate 2XE-8 atm.cc/sec. It is an old leak we found before. Solution: I sprayed high vacuum resin to leak area. It is improved to 3Xe-9atm/sec now. We can leave it there.

2. Exit module 1 module to tank flange o-ring at target module side and north side. Leak rate 3XE-8atm.cc/sec. Solution: replace the o-ring. It involves in disconnect exit module 1 and remove it out. We may or may not change it. Let's check the schedule and discuss it later. We need Travis help on module moving out.
   
3. Exit module 1 north side sqaure service panel o-ring. Leak rate 2XE-7 atm.cc/sec.  Solution: replace the o-ring. It is a straight forward job.  It will be done this shut down.
   
4. Exit module 1 north side round roughing valve panel o-ring. Leak rate 8XE-9 atm.cc/sec. Solution: Replace the o-ring. It involves in disconnecting and removing ITW RV4.  It could be done this shut down.
   
5. Big T tank o-ring seal underneath the flange at exit 1 module north side . Leak rate 3XE-8 atm.cc/sec. Solution: None. All modules and module base flange have to been moved out to replace this big o-ring.  It is a huge project to change this o-ring .  I checked this big o-ring seal every year. It is first time a small leak is found.  Maybe, we could try high vacuum resin spray first.
6. Dump module flange o-ring at the side by Target module. Leak rate 8XE-9 atm.cc/sec. It cannot be confirmed since the TM o-ring is just beside it. Mostly, the leak is on dump module side. We changed TM flange o-ring every year. But we never changed dump module flange o-ring in history. Many copper cooling lines above the dump module has to be removed to remove the dump module out. I do not think we have time to do it this year. Also,  the leak rate is pretty small. Maybe, we can schedule it next year.

  Most these small leaks are close to turbopumps. This could be the reason the ITW vacuum on gauges are still pretty good.

ITW primary and secondary vacuum vessel leak check are done. There is a 5XE-8 atm.cc/sec leak on Exit service cap NW side square panel.  The leak is small. And, it is close to ITW TP3 so it is not affect ion beam line vacuum during operation. We will replace the seal on the panel later.   The rest leak check on air to vacuum seals are good. TM2 water lines are pressurized with 70 psi helium. We did it  3 hours after water lines are purged. No leak was showed during the check.

2021-02-24th: The o-ring on exit 1 NW side square panel is replaced by David Wang and Frank Song. 

During last run， ITW dump circuit had a water leak on an adaptor below the pressure gauge. The top tank flange, slot, and O-ring were water contaminated by the leak. I removed the old o- ring, cleaned up the flange and o-ring slot, and put a new o-ring into the flange. Some  pictures will be attached in this mail later.

Dan and I replaced ITW target pit o-ring seal(.275DIA X42"ID). It is an annual job before first beam to ITW. The old o-ring was moved and the groove was vacuum cleaned. The new o-ring has been installed properly.

TM2 is located in ITW for this leak check. Leak detector is installed between ITW BV2s as before. LD base leak rate 0.0XE-9atm.cc/sec, base pressure 0.0XE-4 Torr. First , I leak checked dump module top flange seal which a small leak was found in last year winter shut down. This time,all ITW  turbo-pumps cooling fans are switched off during the check. Lots helium are sprayed around the dump module top flange this time. I did not see any response on LD.  The check is repeated 3 times. The results are same. There is no leak has been found on ITW dump module top flange seal at this moment. The  further confirming check will be repeated  when TM2 is moved back to ITW with dummy Febiad target  at the end of this month. The rest check result:  1 small leak(1.2 xE-8 atm.cc/sec) is found on one TM2 blue nylon bottom o-ring. This o-ring will be replaced when module is moved out of ITW.  It will be an easy job. Another small leak( 1.1XE-8 atm.cc/sec) is found on exit module 1 service cap top plate to frame o-ring seal. Its location is on east-south side of the exit module 1.This side is close and parallel to exit module 2 west-south side. Vacu- seal sprayer is used to fix this problem.  After two times spray, the leak is disappeared. This is not a permanent fix. The big top plate o-ring replacement is a complicate and dose taking job. It need to be well planned. The leak rate is small, and the leak source is close to ITW TP3 so there is no rush to replace the big o-ring on exit 1 service cap top plate at this moment. But, we need to close watching on this issue and have a job plan for this o-ring replacement since it could get worse in the future. There is no leak has been found on big T tank seal this year as well. All other primary and secondary vacuum seals  in ITW are good. TM2 water lines helum pressurize will be fulfilled In ITW or at TCS later. I will update this e-log when further test are finished.

 2017-01-25:  The O-ring on 60KV bias blue nylon stand is replaced at TCS. I leak check it. It is perfectly good now.

ITW primary and secondary vacuum vessel leak check for  2025 shut down has been done. Also,TM4 internal water line helium pressure test has been finished.  Both results are normal. There are two small old leak on EXit 1 and Exit2 module top plate  o-ring under 1Xe-8 atm.cc/sec which we knoew in past years test. resin spray on leak  area reduce the leak ratee below 5Xe-9 atm.cc/sec. No concern on these small leak.   See attachment  for detail results.

ITW primary and secondary vacuum vessel leak check and TM2 water lines helium pressure test are done today. No major concern. see attachment for small air to vacuum leak we found.  TM2 water lines helium pressure test is fine.   HS and window line leak rate are 1.4Xe-8 atm.cc/sec. all other water lines are below 3.0XE-9atm.cc/sec.