Found spark signs on TM3's containment on the side of the water blocks. They may be OLD or/and NEW sparking signs, but this in not determined at this moment. Please see picture: first attachment. First and second attachment show the profiles of water block and HV lines.

chad fisher wrote:

A video inspection of the lower service tray was performed this morning. Camera was inserted upwards into the service tray/service chase from the containment box. One potential spark mark was identified as well as epoxy not flush with insulator. Fiberglass does not extend into service tray/chase much and does not look, from initial inspection that it will be too difficult to remove. Video can be found in docushare Document-142295

 The attached picture is from the video: showing the fiber glass inside the Service Tray.

Please see the first two pictures of the HV test at atmosphere done on April 19.

First picture shows a big spark between the Extraction Electrode mounting plate holder (at HV) to the Ground Electrode. Please note minimum gap between these electrodes is 7.8mm.

However the biggest visible spark was noticed at the bottom screw hole. (It is difficult to determine if at the 7.8mm gap were concomitant sparks occurring.)This spark started at 22kV and became stable above 24kV.

On April 20, 2017 Chad inspected this area with the Hot Cell camera and found a spark mark on the Extraction Electrode holder plate at the bottom screw hole. See the third picture.

Again it is very difficult with the existing Hot Cell cameras to inspect the areas where the gap is small (at 7.8mm gap between the conical surfaces of the Ground Electrode and Extraction Electrode holder)

In the second picture there are 2 small sparks: one on the top and another one on the right side at the lines wrapped in Fiber Glass. These sparks started at 20kV.

On April 21 the HV test was repeated with the Containment box ON and the sparks occurred again, at the same locations and at the same voltage.

Please see TM3's Updated Schedule (the current schedule) at the SHC and TCS.

For the record I am uploading TM3's Initial Schedule at the SHC and TCS.

Today a HV test at atmosphere was performed for Each Line(s), while floating the other lines.

Please note the Einzel Lens line (Y) was grounded.

Tests performed:

1. Applied up to 29kV to "(A) OVEN -"

Sparks occurred at 29kV at the Fiber Glass inside the Service Tray; and at the right side at the lines wrapped in Fiber Glass.

2. Applied up to 29kV to "(B) OVEN +"

Sparks occurred at 29kV at the Fiber Glass inside the Service Tray.

3. Applied up to 6-7kV to "(C) TUBE -"

Could not identify the sparks; it was a continuous discharge.

4. Applied up to 6-7kV to "(D) TUBE +"

Sparks/discharges occurred at 6-7kV at the Fiber Glass on the right side at the lines wrapped in Fiber Glass. We had to turn OFF the lights in the Hot Cell to identify the small sparks.

5. Applied up to 4kV to "(P-Q) COIL +"

Discharge occurred at 4kV. Could not identify it.

6. Applied up to 29kV to "(R-U) COIL -"

Sparks occurred around 27-29kV at the Fiber Glass inside the Service Tray; and at the right side at the lines wrapped in Fiber Glass.

Tom saw a spark at 27kV between the Extraction Electrode holder and the Ground Electrode.

Saw also a spark at the Ring Alumina insulator in the Service Tray, located on top of the second comb insulator with Epoxi.

7. Applied up to 27kV to "(E) Cavity or MSP, (G) Gas, (J) Heat Shield" - all these are connected together at the BIAS voltage.

Sparks occurred at 27kV at the Fiber Glass inside the Service Tray.

8. Applied up to 23kV to "(I) EE" - this is for the Extraction Electrode.

Sparks occurred at 23kV again at the same spot near the bottom screw hole, between the Extraction Electrode holder and the Ground Electrode.

9. Applied up to 27kV to "(F) Plasma"- this is for the Anode.

Sparks occurred at 26-27kV again at the same spot near the bottom screw hole, between the Extraction Electrode holder and the Ground Electrode.

Please see attachment for TM3 May 1-15, 2017 Tentative Schedule at the SHC and TCS.

Today a HV test at atmosphere was performed for Each Line(s), while floating the other lines. THIS TEST AT ATMOSPHERE IS THE FIRST ONE AFTER THE FIBER GLASS WAS REMOVED.

Please note:

a). the Einzel Lens line (Y) was grounded.

b). after the fiber glass was removed the "R-U COIL" line and the "(F) Plasma" (which is the Anode line) were shorted to the BIAS voltage.

Tests performed:

1. Applied up to 32kV to "(A) OVEN -"

Sparks occurred at 32kV between the Extraction Electrode holder and the Ground Electrode.

2. Applied up to 33kV to "(B) OVEN +"

Sparks occurred at 33kV but we could not identify the spark location.

3. Applied up to 31kV to "(C) TUBE -"

Sparks occurred at 31kV between the Extraction Electrode holder and the Ground Electrode, at the top and the bottom.

4. Applied up to 30kV to "(D) TUBE +"

Sparks occurred at 30kV between the Extraction Electrode holder and the Ground Electrode, 2 spots at the bottom.

5. Applied up to 30kV to "(P-Q) COIL +"

Sparks occurred at 30kV between the Extraction Electrode holder and the Ground Electrode, all around.

6. Applied up to 30kV to "(R-U) COIL -", to "(F) Plasma" the Anode, to "(E) Cavity" or MSP, "(G) Gas", and  "(J) Heat Shield" - all these are "connected" together at the BIAS voltage.

Sparks occurred around 29-30kV at the Extraction Electrode holder and the Ground Electrode, at the bottom.

8. Applied up to 23kV to "(I) EE" - this is for the Extraction Electrode.

Sparks occurred at 23kV again at the same spot near the bottom, between the Extraction Electrode holder and the Ground Electrode.

Today TM3 was conditioned up to 50kV. At 50kV sparking started and to go higher in voltage it needs more conditioning time. Lowered it to 49kV for the night.

Today TM3 HV conditioning went up to 65kV. I'll leave it here over night. ISAC OPS have instructions to keep an alarm on the HV, and ion gauge and turbo pump (TP2 tripped 3 times due to sparking).

Today the voltage was raised from 65kV to 65.7kV. After about 10min at this level TM3 started current limiting. TM3 was not sparking when this happened.

ISAC OPS turned it OFF and then tried to ramp it back ON, but could not do it due to the current limiting.

I turned OFF/ON the PS (locally) 20ming ago and and then tried to get it back from the Control Room, but around 4-5kV it started current limiting.

Turned everything OFF on EPICS for the time being. We'll investigate on Monday.

Over the night the sparking rate at 65kV was from 6 to 2 sparks per hour. It tripped OFF once over the night: backing valves closed, tripping the turbos, tripping IG1 and turning OFF the BIAS. At that time ISAC OPS got it back smoothly.

Anders Mjos wrote:

50 kV stable with less than 1 spark/h during the weekend by RIB obs. Today 57 kV reached, but observed sparking on the resistors of the new HV cable. The cable will be removed to take out the resistors, before reinstalling it. The target hall was locked out, but has now been reopened. This was to avoid sparking to the HV cover.

 EL was brought to 27.5kV.

The annual inspection of the mini-storage vault and main storage vault was completed June 23, 2023. The following items were checked:

• Cabling and cable management
• Connectors
• Controls box - internal wiring and components, functionality
• Limit switches - functionality, wiring, mounting
• Motor
• Bearings
• Set screws
• Miscellaneous fasteners

The inspection was generally successful. A couple of minor findings were:

• Bearings for both the main and mini storage vaults must be greased. This is planned for a different day as it involves removing the mini vault's door.
• There was a small piece of metal on the track for the mini storage vault which was causing the door to "bump" over it as it passed over. This piece was removed and the door behaved normally.
• The wheel track for the main storage vault was dirty - it was cleaned
• It was suggested that the 120 VAC power cable for the mini storage vault controls box should be connectorized - this will be added to the "to-do list" for the future

chad fisher wrote:

An autopsy was performed on UCx#3 yesterday afternoon. This autopsy followed the plan written by Anders. Indeed, both sides of the target oven had seperated from the central block.Pictures were taken by Anders and Pierre. After the disection the target was placed back in a can under argon. Any small piece were placed in a zip lock bag and also put in the can under argon.

Pictures are available on DocuShare:

https://documents.triumf.ca/docushare/dsweb/View/Collection-8189

ISAC e-log entries:

https://web.accel.triumf.ca/isac_elog/Elog_shift_view.pl?shiftid=10803

See attachment for autopsy plan.

The target was inspected today.

It was found that the target tube had broken on both sides of the centre block in the region that contain target material. The Ta-foil heat shield was removed from the let side tube to allow inspection.

Photos can be found on DocuShare:
https://documents.triumf.ca/docushare/dsweb/View/Collection-9357

By pressurizing the water lines with 70 psi helium David and I detected a major leak on the Coil 1 circuit. The response maxed out on the leak rate on the leak detector and we could also see a pressure increase on the leak detector. ISAC controls reported a change in vacuum at the same time (link).

The Heat Shield and Coil 2 circuit was checked before we moved to Coil 1. No response was detected on these two circuits. We would like to check the remaining circuits as well, but this cannot be done today due to the large amount of helium still present. The remaining circuits will have to be checked tomorrow morning.

All water circuits except Coil 1 were leak checked by David and Anders. No obvious signals were detected except some small possible responses. See attached notes for details.

The SiC#29 CTL target has been taken apart with the help of Isaac and Chad. Electrical measurements were done between Target and Heat Shield as the target was disassembled. Work was done on October 2nd, 4th, 7th and 8th.

The megger showed about 30kOhm at 50V with the following changes

• Bolts for CTL block loosened
• Above bolts removed
• CTL block pulled away from Heat Shield
• CTL block removed
• Heat Shield lid removed
• Bolts for target removed
• Shims between target and insulators

The megger showed about 50kOhm at 100V with the following changes

• Target removed. Measured between cathode restraint and HS.

The megger showed OL at 540V with No 3 insulator removed. A measurement on No 3 insulator while it was sitting on the HS showed 70kOhm at 120V confirming that the insulator can no longer hold voltage.

While taking off the coil retainer plate, Chad noticed that all bolts were not tight.

Photos are available on DocuShare.

as measured today in the electrical room by David and Anders

The conductance check on the electrical check was found to be outside of accepted values for the TBHT at 7.0 mOhm. A successful attempt to reduce the conductance was made by re-tightening the bolts on the TGHT legs in the SHC. Grant operated the manipulator and torqued the bolts to about 1/8 of a turn with the air ratchet. The conductance across the TGHT (A-B) could be improved from 7.0 mOhm to 6.2 mOhm by re-tightening the bolts. The value is still somewhat higher than usual, but was deemed to be acceptable. Measurements attached.

with TM4 in ITW as measured today in the electrical room by David and Anders.