Argon vented ITE station. ITEVV1S and ITGT SV3 were closed after venting.

 TM4 was connected in ITE.  pics attached FYI.

Yesterday and today module conditioning was done on Tm4 in ITE. This is the first ramp up after the shutdown and ITE is planned to run at high voltages for the first weeks. The module is behaving well - went up to 40kV yesterday, stayed there for an hour, and up to 46kV today. Current draw is 113uA at 46kV. No serious sparking.

Tuesday, May 23, 2023, 09:32 :  Ramping up again, easy to 45kV. Drawing 132uA at 49kV. Still behaving quite well.

When I tried to raise the anode voltage in cathode bias mode on May 23 evening, I found the target or tube shorted to HV common. Investigations in the faraday cage today showed the same. I removed all the new electronics (resistors, gemovs, etc) from the power supply to no effect, so I disconnected the TGHT supply and pushed it away from the busbars. There was still a short. David Frank and I then went down to the pit and disconnected everything to measure the module. The module itself showed no short, and the bus bars in the chase for TGHT showed no short, though the ones for TBHT still showed the short.

David and Frank reconnected the module and I disconnected the TBHT supply in the faraday cage, then I found no shorts to TGHT/TBHT. When I reconnected everything there were still no shorts. There must have been a short in the TBHT line in the faraday cage, and another short in the TGHT line in either the faraday cage or on the module top. Both these shorts got resolved by taking everything apart. Still not sure how it happened.

Next I found I could not raise the anode voltage above 230V, it looked like it was current limiting but since the current limit was high, I figured it had something to do with the new electronics installed. I disconnected them all the in cage and that solved the problem, and then reconnecting the gemovs that go from the PSU terminals to HV common caused the problem again, so I left those disconnected.

argon is being supplied at 6 psi to TM4. 

 TM4 with TiC#5 was disconnected in ITE and moved to NHC.

 TM4 with new target SiC#45 was connected in ITE, all TPs are running at their full speed.

ITE water signal interlock check including HS,EE, TA, TU, MSP. Coil1 , C-window ,2a-window, 2A tank, 2A shielding plug , 2A dump, 2A collimator  are done. All things work.

 TM4 with new target UCx#42 was connected in ITE. 

 TM4 with spent target UCx#42 was disconnected in ITE and has been remote moved to NHC this morning.

 TM4 was connected in ITE with new target Ta#65 installed. see attachment in detail.

TM4 with spent target Ta#65 was disconnected in ITE and moved to SHC.

Pumped down the gas lines in ITE on Tuesday Nov. 28 2023 and opened the CF4 bottle valves. Missed the small section between the regulator and SV2 though, so will probably redo it.

Pumped down again on Dec. 12 2023. Was taking a long time so might not be as good as earlier. Maybe there is a leak in there...

 To deliver stable beam to RadMol, started heating UCx#43 up again. Target was overheated during initial conditioning in Nov but then ran well for 4 weeks. During the run time, the TGHT voltage jumped around and this was reflected in the ion current, but yields seemed unaffected.

When re-heating it, the TGHT voltage was very unstable and once it got to 440A, it went into voltage limiting mode. We ramped down and it was still voltage limiting, but turning things off solved it. We ramped back up and it did about the same thing. TBHT voltage and current remained steady. Looks like a heat generated issue.

Measured the resistance in the lines from the electrical room. Resistance of the lines to ITE should be 1.19mOhms for TGHT and 1.95mOhms for TBHT. TBHT positive to negative had a resistance of 7.9mOhms from the electrical room today, and 5.7mOhms on module top when measured Nov. 8. This seems to track.

TGHT positive to negative was measured at 27.6mOhms today (and was jumping around), whereas it was 7.14m Ohms on Nov. 8.

10V @ 440A is 22.7mOhms, so it makes sense that it limited. Tried with increased voltage (up to limit of 16V) but this didn't help. Declared the target dead on Jan. 11.

David measured resistances on the module top and found (in mOhms):

A-B = 27 (TGHT)

A-C = 7.473

A-D = 6.380

B-C = 26.053

B-D = 25.569

C-D = 5.212 (TBHT)

So looks like the tube is broken on the B side.

Tm4 waterlines helium pressure test and TM service cap helium leak check was done last Friday. All water lines were pressurized with 70psi helium for 3 minutes each. The 3 minutes stable leak rate on all lines are less than 4.0 X E-9atm.cc/sec. some of lines had surging leak rate to 2xE-8 atm.cc/sec at the first 10 seconds of pressurization which should be a gas hammer result at the beginning. Based on the numbers, I would say all water lines are leak free still.  I did helium spray on TM4 service cap. There could be a small leak in high E-9 atm. cc/sec on ion gauge and steer service panel o-ring.  I will replace this o-ring when module is moved out of ITE. Other seals are leak free or less than 2.5X E-9 atm.cc/sec leak rate which are good. I am pretty confirm there is a small leak on ITE entrance module top. The leak rate and location will be confirmed when the rest of leak checks in ITE pit are done.

 TM4 with spent target UCx#43 was disconnected in ITE and is ready moved to SHC. see attachment pls.

ITE primary and secondary vacuum vessel leak check has been done. SST bellow for 2A3M19  wire scanner on entrance module top has a big leak to E-5 atm.cc/sec on tiny helium spray. The bellow will be replaced in March by probe group. The LD base leak rate is affected by this big leak so i cant keep the LD scale at 0.0Xe-9 atm.cc/sec during the leak check. Other seal are leak free to 8XE-9 atm.cc/sec. I have no big concern on ITE vacuum seals status by the result.

ITE was set up for HV tests - this time the module plug was not in so the BIAS and EE had to be bypassed. NOTE: ITE:BIASPLC must also be bypassed for this to work. Currently it is located on the vacuum bypasses page, but may be changed to the optics page soon.

ITE was ramped to 60kV in steps of 1kV easily. It sat at 60 for about 1.5 hours with a current draw around 173uA. It was not entirely stable though, and appears to have sparked many times. None of them seemed very large, but hard to tell.

When ramping down, current dropped quickly with the first couple steps. Data saved as isac/data/ITE_HVtesting_shutdown2024

ITE entrance module has been disconnected per document 190510. Its a preparation job for next month module moving out to SHC.