5 shielding blocks have been transferred from ITE to ITW. 

Doc # 181007

TM4 with spent target UCx#45 was disconnected in ITW and moved to SHC.

 TM4 move from ITW to SHC is smooth.

electrical check  on TM4 UCx#45 target at SHC after operation is done.   see attachment.

TM3 has been moved  from SHC to TCS by David and Frank. The move is smooth.

TM3 with UCx#44 electrical check and leak check are good. see attachment.

HS line 70 psi helium pressure test at TCS: no leak at 0.0xe-9 torr.

TCS was argon vented this morning between 7:00 to 8:30 am before module was moved to ITE.

The move is smooth and successful.

Tm3 has been connected in ITE.  see attachment.

ITE water signal annual interlock check is done. Ed helped me on this check. Everything works normal.

Tuesday, May 14, 2024, 10:26 :

Ramping up bias/EE/EL on ITE - will see if the HV cage in the pit can hold 60kV or not.

At around 50kV the bias read current starts to get jumpy. Doesn't look like its an issue for the voltage, but definitely instability increases.

Occasional sparks seem to increase the EL current significantly...

David heard some sparks in the target hall. Looks like from heat shield feed through to the top of the cage. Several sparks heard in the TH also changed the einzel lens draw current significantly. These feethroughs are not far from each other so could be related.

Apparently the sparking also tripped off all the optics and heaters in ITW, by changing the state of the water flow interlock. Interesting and not seen ever before. Will test again with the cage off, rather than risk tripping ITW again.

Tried ramping up the voltage on just the EE. Seems the limit is 7kV - at that level it gets sparky and unstable. Should be investigated (should hold 10kV) but not critical for module function.

Wednesday, May 15, 2024, 10:05 :

HV cover was removed this morning and the MAA was locked out.

Started ramping things up, was very easy until around 58kV. At 59.5kV a spark tripped off the EL. Canbus controller had to be power cycled to fix it. Bias current is much more stable in this configuration.

Ramped up again while listening from the TH to see if it was sparking outside. Went slowly to 60kV (left EL at 29kV) and didn't see any outside sparks in the first 10 mins, couple sparks in vacuum. But after 15 mins a spark seems to have fried the EL canbus card. We were not in the TH so not sure if it was on the outside or not.

After 2 hours a spark tripped off both ITE and ITW. Looks like it makes a water interlock go bad momentarily, but after the trip the interlocks seem fine.

Tuesday, May 28, 2024, 16:41

Running TM3 at any voltage in ITE produces fairly destructive sparks. There are not many but so far they have tripped off all optics in ITW, the water flow interlocks (later forced on to prevent this), the EL (generally comes back but killed the canbus card once), destroyed two vacuum gauge controllers, and may have contributed to the cathode short on ITE-TM3-UC44-LP-FEBIAD.

The conditioning process seems to go as planned, but the occassional inevitable spark still trips things, which is making it difficult to run stable.

Will continue with regular HV conditioning to see if this helps. Control over the current limit on the ITE:BIAS supply would also help, but seems a complicated thing to add according to Roberto.

TM3 sat fine at 53kV overnight and at 58kV for several hours. The EZL trips off maybe once every 2-3hrs or so, which is not ideal but liveable. This was with the TGHT and CHT power supplies forced, so not sure if we would know if they would have tripped...

CONCLUSIONS:

1. TM3 has been commissioned for beam delivery after one week of delivery of UF to TITAN using a FEBIAD ion source in anode bias mode. Cathode mode was also used, so all functionality of the target except IGLIS current/voltage delivery through the mutlipin has been tested successfully.
2. TM3 still requires commissioning at high voltage with protons to be considered fully commissioned, this will be done July 2 2024 due to problems with the cyclotron.

 the five shielding blocks have been moved from storage area to ITE and is ready for beam delivery.

submitted WP# I2024-05-22--1

actived  WP # I2024-05-23-4

 TM3 with target UCx#44 was disconnected in ITE. 

TM3 UCx#44 after operation electrical check at SHC . see attachment.

Carla: Looks like the short on the cathode observed while trying to operate the FEBIAD in cathode-bias mode is still there. Will do investigations in the hot cell during disassembly.

Tm3 has been moved form ITE to SHC. the move is smooth.

A new gas system for FEBIAD operation was installed in ITE to enable us to use a calibrated leak which is attached to the target heat shield. This will allow us to control the quantity and purity of the gas going into the system, and to switch quickly between gasese and pressures.

The schematic of the system is attached. The use of the ballast container is likely not needed - it was originally included in case we want to run the system at pressures greater than 1 ATM. The roughing pump inlet limit is 1ATM, so it was envisaged to used the ballast container to reduce the pressure to that level or below before opening the system to the pump. But since it has been difficult to commission the system over 1ATM and this opens the door to several concerns about gas leakage, it was deemed better to keep operation below 1 ATM. This tank will likely be removed.

The storage tank was implemented because we are not sure if irradiated gases will be pulled out of the target lines when we pump on them, and so this was devised as a way to test that. The alternative is to have the exhaust of this pump go directly into nuclear ventilation by way of a plastic tube leaving the faraday cage, however this solution is also quite some work to implement. So the consensus was to start with the storage tank and sample it several times to understand what sorts of radioactivity we are dealing with, then make a decision about future operations.

This system has been tested offline using the development target UCx#44 and appears to work well. Unfortunately there were no protons available for this beam time so the gas sampling part of the system was not tested.

The operation of the rest of the system worked reasonably well. Beam disappeared when pumping out the lines and reappeared when re-opening the gas bottle. It seems that the storage container can be used to pump out the lines about 7 times before it gets up to around atmosphere, as was estimated based on volume. The pump can get the lines down to about 250mTorr as read by the pressure gauge DG2 on the module top, given about 30mins of pumping.

We did have some issue with the gauges, HV sparks destroyed both controllers and so we were unable to monitor pressures as we would have liked. It is possible one gauge itself is broken as well, to be investigated.

It may be that the gas leak we used was too small, but the idea of changing the pressure on the module by changing the needle valve didn't seem to work. This is not sure since we didn't have a reading on the pressure, but watching the ion beam as you turn the gas back on seemed quite binary. You would see no change until you had the needle valve fully open. This may be different with a larger leak, since this leak required about 1ATM in the lines to see anything. It is still not clear why this behaviour was different than the tests at the test stand, in which 0.5ATM of upstream pressure produced about 2nA of beam.

This system is considered a prototype and is not turned over to ops for operation. Further commissioning is required.

TM3 and UCx#44 ran in ITE but issues with the cyclotron prevented proton beam delivery. Nonetheless, the target was heated and provided stable beam to TITAN as well as for tuning and some tests.

Results of inspection of TM3 module after run:

The module looked pretty good. There were no marks on the polished surface of the containment box, next to the water blocks, that were visible. But we didn't remove the box, only looked with the camera and it was visible by turning the module. So some things may have been hidden. There were some black marks on the door, near the bolts that hold in the handle (see attachment). This seems a very unlikely spot for sparking as the fields should be considerably lower than at the target handles, lower down. Maybe the spots are from oil left on the door that had a chemical reaction? There is one very faint matching spot on the top of the copper trident connector, but it doesn't look much like a spark mark. The other two marks have no corresponding mark on the source tray. There were no marks on the ground electrode, or anywhere else on the source tray. There was a scuff on one of the trapezoidal insulators, but it could have happened during installation.

Results of inspection of the target after run:

The FEBIAD target developed the same cathode short we have seen on almost every FEBIAD we run online - a high resistance short from cathode to HVC that prevents voltage on the cathode. This time the short remained after cooling the target, and David measured 208kOhms with the ohmmeter on the module top (11kOhms with the megger). We used a multimeter in the hot cell to test after the target had been dismounted and we found no short. So it must be related to either the position of the target (upright vs face down) or time (a conductive trace on an insulator oxidizes and becomes non-conductive again) or some pressure/shaking during the de-installation.

There weren't many marks on the target - a faint mark near where the faint mark on the copper trident was observed, some marks on the EE which had no counterparts on the ground electrode. See pictures.

 TM4 with new target UCx#43 was electrical and leak checked on SHC.

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

TM4 has seen significant coating of the main standoff insulators and various other components stemming from failure in UCx#43 target. See attached pictures showing coating on containment box, support frame, main standoff insulators, standoff insulators high voltage shield etc. Note tracking marks on main standoff insulators.

Wednesday, January 24, 2024, 12:54 Carla's edit:

Meggered all HV components relative to HV common and HV common relative to ground. Nothing out of the ordinary, HV common to gnd was 700MOhms at 1kV. Seems whatever got onto the insulators is non-conductive, or is not as bad as it seems.