Target elevation measurements and beam spot plots were completed on the T1-MK2 target and the target is now fully repaired and ready for use.  It will be returned to the storage pit when cranes are available.

A copy of the elevations measurements and beam spot plots is attached.

The target ladder was detached, old delta seals removed, sealing surfaces cleaned using scotchbrite pad and a dremel tool, and delta seals were installed on the lower face of the upper slide plate.  The target was leak checked and found to have no significant leaks (no response from 2s helium spray at previous leak location on upper slide plate).

The profile and protect monitor electronics were checked by Bill Rawnsley and appear to be functioning normally.

The T1-MK2 target is now ready for use in the beam line.

- T1-MK2 target moved from storage pit to hot cell
- Removed unused proximity sensor and associated wiring (stored in tool-port boot box cabinet)
- Tested profile monitor actuation: seems stiff, but moves ok;  start travel @ 30psi, fully in position @ 50psi
- Replaced vacuum flange o-rings: Plug (#202), Feed-through port 1 (#222), Water supply tubes 1 and 2 (#208)
- Replaced all nylon ferrules for water supply tubes
- Leak checked water supply tubes: leak tight
- Replaced rusty nuts on profile monitor lift plate
- Profile monitor limit switch wiring replaced (D. Cameron)
- Heat shrink applied over motor wires (D. Cameron)
- Position micro-switch connectors replaced (D. Cameron)
- All wiring wrapped with protective coil and secured with PEEK zap-straps (D. Cameron)
- All limit and position switches tested: ok
- Profile monitor bellows straightened (noticed rotation of base seems stiff)
- T1-MK2 target moved to storage pit location #3
- T2-MK1 target moved from storage pit to hot cell for re-wiring

 

When the damage to the T2 Protect Monitor was found to be caused by flying debris from a vacuum spike (see e-log #179), it was decided that the T1 Protect Monitor should also be replaced.

Oct 8:

- The T1-MK2 target was transported from the beam line to the hot cell after the T2 target was returned to the beamline (see e-log #180).  The T1 target was 38.9mSv/hr at 0.5m

- The T1 target was inspected in the hot cell: profile monitor looked ok, protect monitor damaged with holes and dents on upstream side (see attached photos), position 4 target looked ok with beam spots roughly centered (see photos)

- The old protect monitor was removed in the hot cell and a new monitor supplied by Probes Group was installed (previously undocumented brass spacers were seen over the monitor cassette alignment pins on the target)

- The T1-MK2 profile and protect monitors were checked by Probes Group at the hot cell --> both ok

- Measured elevation of the new T1-MK2 protect monitor: 1831.1mm on entrance side (previously 1831.0 --> ok)

- Position 4 target entrance side elevation checked: 1832.9mm (previously 1831.9mm --> 1mm discrepancy)

- Position 4 exit side elevation measured: 1832.4mm (previously 1832.1mm --> ok)

- Protect monitor exit side elevation measured: 1833.7mm (previously 1833.3 --> ok)

- T1-MK2 target returned to beamline at approximately 5pm, no problems

- Vacuum pumped down quickly and it was decided that a leak check would not be necessary

Oct 9:

- All target services attached

- T1 target moved to Position 0 using remote control box

- T1 package started, no change to T1 vacuum

- T1 profile monitor and protect monitor electronics checked by Probes Group from mezzannine --> both ok

- T1 motor drive cable conected to controller in 1A racks.  The T1 ladder can be moved from the 1A racks mimic panel (T2 still requires portable control box)

- Actuation of the T1 profile monitor was tested --> actuated properly, no change in vacuum

- T1 cooling package expansion tank level checked: no change

- The T1 area is ready to be covered

 Bill Rawnsley and Mike Russell performed a 'blip' test on the T1-MK2 profile monitor and protect monitors today.  A possible bad wire at  #9 location in the vertical array on the profile monitor was found (this is two wires above center).  Bill did not think this was a serious concern and beam tuning can be (and has been done in the past) with wires missing.  Otherwise the responses were normal for both monitors and the scope readings were almost identical to when this target was checked in August 2011.

The T1-MK2 target was transferred from the beam line to the storage pit in hole #5 using the transfer flask.  A maximum field of 7.2mSv/hr was measured at 0.5 meters from the target.  A video was taken while the target was lifted from the monolith and can be found on Isaac's PC (too large to upload).

The blocks to the west and east side of the T1 monolith (level with the monolith) were swiped by Danka Krsmanovic and no contamination was found.  These blocks will therefore not be painted this shutdown.

The three active filters removed from the T1 cooling package have been labelled and stored in the area north of the BL1A blocks boot box with permission from Danka.  The bag with the filters is 100microSv/hr at 0.5m and 2mSv/hr on contact.

 A leak check was performed on the T1-MK2 target in the hot cell today and confirmed successful leak-free installation of the new water supply tubes, delta seal retaining rings, and delta seals on the upper slide plate.  The remaining tasks are to install delta seals on the lower slide plate and have the protect monitor and profile monitor electronics checked by diagnostics group.

  After removal of the leaky target cassette at position 3, plugs were installed on the target ladder and a leak check was performed.  With the target pumped down to approximately 10 mTorr, and helium detector gauge baseline of 9 on the 10X scale, a response of up to 25 on the 500X scale was observed when leak checking the right side delta seal on the lower face of the upper slide plate using a standard 1s spray of helium at 3 psi.  The flange screws were tightened and the leak check repeated.  Under the same conditions there was a response of up to 60 on the 100X scale - There was still a leak, but not as severe as before.  The screws were tightened further, and the target leak checked again, with no change.

At time of installation a response of  up to 10 on the 100X scale was found at the same location.  This target was found to be water leak tight and was used in  the beam line for ~4 months.  It is possible that the seal is still water leak tight.

The seal must be replaced or a static water test performed to show that the target is water leak tight.  Seal replacement will take approximately 2-3 days. 

 The following work was performed on the T1-MK2 target assembly during the September 2016 Mini-shutdown:

Monday Sept 26:
- Target moved from beamline to hot cell (28mSv/hr at 0.5m)
- Position 4 beam spot on entrance and exit windows photographed (attached)
- Target flushed with fresh water, positions 0, 4, and 5 blown out with air, then left overnight with air blowing through position 0 at 10psi supply
 

Tuesday Sept 27:
- Pumped on target water system using lab leak detector:  reached 1.0E-3 Torr and E-8 Torr*L/s range in < 5 mins
- Initial leak check performed: TPP < 1.0E-3 Torr, Base leak rate: Low E-9 range, 3psi helium supply, ~0.5s bursts
- Response up to 3.6E-6 at lower left side delta seal (when facing ladder), up to 4.9E-7 for lower right seal  (note: T1 area at good vacuum level prior to mini-shutdown),  All other positions no response, or response in low E-8 range (assumed drift or insignificant helium leak)
- Plugs at positions 1, 2, and 3 removed.  All threads inspected, brushed with wire brush, rinsed with acetone, and blown dry with compressed air
- New targets installed:  Serial #101 at Position 1, #102 at Position 2, and #103 at Position 3  (Position 1 threads significantly stiffer than others, but no major issue)
- Leak check repeated: similar response from all locations including all beryllium target windows  (concluded suitable for use in beamline)
 

Wednesday Sept 28:
- Profile monitor actuation checked in hot cell:  movement starts at 27psi, fully actuated at 48psi, limit switches functioned properly
- All target ladder micro-switches checked, ok
- Vertical and horizontal target position measurements taken using procedure in Document #50194  (PDF attached)
 

Thursday Sept 29:
- Target returned to beam line and all services connected
- Target info sheet and elevations delivered to Ops, XTPAGE 7L updated
- T1/T2 PLC information updated with new cassette information
 

Friday Sept 30:
- Vacuum pumped on the T1 volume.  Quickly 200mTorr (threshold for T1 Vac OK signal).  Edi reports pump-down slower than usual, will evaluate on Monday.
- T1 package started (no change in BL1A vacuum)
- Profile monitor actuation checked from control room (actuated normally)
- T1 profile monitor and protect monitors checked by Mike Russel and Victor Verzilov:  profile monitor normal, protect monitor signals low but Victor expects it is fine and give ok to cover

 

 March 29 Monday

- moved T1-MK1 target from beamline to hotcell  (field from target 15mSv/hr @ 0.5m)

- flushed water through position 4

- flushed air through all positions

- left air running @ 5psi overnight through position 5

- potentiometer reading "O/L" at position 3, all other positions OK

- all micro switches OK

- removed the left plug (when facing ladder) at position 1 , but after reading elogs it was found that the right plug at position 1 was having issues. Will have to replug left with new plug

March 30 Tuesday

- pumped down with cold trap, started at 10:00

- test port 2.0 E-1 Torr after 1 hour

- cold trap removed, cleared, dried, refilled

- 11:10, started pumping, found leak at lab vac tubing joint. Fixed.

- 11:16, started pump again

- 11:24, 1.0 E-3 Torr TPP, 1.4 E-9 L/s leak rate

- preformed leak check, no response at all locations

- position 4 Be target removed (required hammering). Damaged spot, potential start of hole observed at center of beam spot (see attached photos)

- position 5 graphite target removed (required hammering)

- New 12 mm Be target #108 installed at position 4

- New 12 mm Be target #109 installed at position 5

- leaving position 3 plugged as the potentiometer is reading "O/L" as indicated from the multimeter 

- New plug installed on left side of position 1

- 15:47, stated leak check pump down

- 15:57, 2.0 E-3 Torr 

leak check results

All positions were no response (NR) except

Position 1, Right side plug) 5.9 E-8 Torr

Position 3, Left side fitting) 5.3 E-9 Torr

Position 4, Left side fitting) 4.2 E-9 Torr

All locations should be H2O tight

March 31 Wednesday

- took vertical and horizontal measurements of the new position of 4 and 5 targets (updated elevations PDF sheet included)

tested profile monitor activation

- started moving at 15 psi 

- reached limit at 35 psi

- both limit switches OK

- Cleaned base of vacuum flange and top of support ring

- prepared target ready for transport with flask (ladder in position 0)

- contacted MCR to update XTPAGE 7L target details

- emailed Tony Tateyama to have PLC lookup tables updated with new target info

The profile monitor actuation tests were completed for T1 and T2. No abnormalities were noticed in vacuum during either test.

Note: an issue was observed with T2-MK1 - see e-log 290. The issue was resolved.

 The #6 male Hansen fittings for the T1-MK1 and T2-MK1 targets (both currently stored in the target storage pit) were replaced today with new units.  Some of the target assembly Hansen fittings had shown signs of leaking and the internal seals are not easily replaced.

"120V" warning labels were put on the micro-switch IN and OUT limit sensors for the profile monitors on both targets.  These are the only micro-switches on the assemblies that still run at 120V after the PLC controls upgrade.

 T1-MK1 target transferred from hot cell to storage pit position #3 to free up the hot cell in preparation for shut-down activities.

Current device locations in storage pit:

Pos 1: TNF Resin Can
Pos 2:    empty
Pos 3:  T1-MK1 Target
Pos 4:  T2-MK1 Target
Pos 5:     empty 
Pos 6:     empty 
Pos 7:     empty 
Pos 8:     empty 
Pos 9:     empty 
Pos 10:   empty 
Pos 11:   empty 
Pos 12:  Liquid Deuterium Target
Pos 13:  Kaon Target
 

- T1MK1 target transferred from storage pit to hot cell (max field: 4700 μSv/hr @ 0.5m)

- Protect monitor with incorrect wiring removed (20μSv/hr on contact, 60cpm contamination on 44-2 meter)

- Scott Kellog fixed the wiring and returned the protect monitor (correct wiring schematic is TDE0301E, previously used incorrect schematic D10649)

- Installed new protect monitor on target

- Profile monitor was found to have broken wires and will be replaced with new more robust design (0.005" thick gold coated molybdenum wires)

- Bill Rawnsley confirmed that protect and profile monitor wiring harnesses are wired correctly using resistor packs

- Bill was double-checking the wiring of the new profile monitor before installation and found that it had been wired incorrectly.  Scott K. will fix the wiring and return the monitor mid next week for installation.

- Leak check was performed on the target and confirmed that all seals and target cassettes are leak tight

- Re-wired profile monitor was received from Probes Group and installed on the target

- Protect and profile monitors were 'blip' tested, both OK

- Profile monitor actuation and limit switches tested, all OK (monitor starts to travel @ 20psi, fully engaged at ~40psi)

- Elevation measurements taken for profile and protect monitors

- Target ladder moved to position 3 (12mm Be target)

- Noticed strange 'click/twang' noise when moving target ladder, found to be caused by twisted bellows on water supply tube

- Bellows was straightened, and the target was leak checked again (still leak tight)

- Noticeable wear was found on potentiometer wires.  Pot values still read accurately.  Travis C. inspected and does not think they need urgent replacement.  Will have Probes Group look at it next time the target is in the HC (they are very busy now).

- T1-MK1 target transported from HC to storage pit location #3  (ready for use in beam line)

- T2-MK1 target transported from storage pit to HC (max field: 97,000 μSv/hr @ 0.5m)

 The T1-MK1 target was leak checked on April 15th at the T1 monolith by Ron Kuramoto and Edi Dalla Valle.  No leaks were found.

 - On Nov 13 at ~1am the BL1A vacuum went bad.  The T1 and T2 volumes were isolated and pumped on separately, the results indicated a water leak from the T1 target.  The level of the expansion tank was slightly below normal at this time, but not enough to be conclusive.  The leak was confirmed at ~9am by starting the T1 cooling package which caused a dramatic vacuum spike.  Approximately 1" was lost from the expansion tank when the package was started, equal to approximately 2.5L of water.

- The T1-MK1 target was removed from the beam line and transported to the hot cell.  A mound of ice was visible on the target lower plate while it was being lifted.  A radiation field of 160mSv/hr was measured at 0.5m from the target during removal.  Upon inspection in the hot cell, a small but clear hole was visible on the entry window of the position 3 target cassette just slightly above and to the right of center if facing downstream.  No water was visible on the profile or protect monitors.  Approximately 1" of water was visible in the base of the T1 monolith.  The monolith was left open to air overnight, and approximately 0.5" of water was visible in the morning on Nov 14.

- Vacuum group was consulted, and given the relatively small amount of water remaining they agreed to pump the water out of the beam line rather than have Remote Handling group try to remove the water before target installation.  The T1-MK2 target was transported from Hole #3 in the storage pit to the beam line.  A field of 5mSv/hr was measured at 0.5m from the target.  All services were attached.

- An electrical check was performed on the profile and protect monitors by David Cameron from the 1A mezzanine.  Both devices appeared normal.  Plant Group then began to replace the blocks over T1.  Graham Waters updated the control software so that the correct target ladder potentiometer values are referenced.  An updated target information sheet was prepared and delivered to Operations (PDF File Attached)

On May 23, 2024 two sets of plugs from position 1 and 3 and a 12mm Be target from position 5 (serial #109) was removed from T1-MK1 in the Meson Hall remote handling hot cell.

The plugs and spent target are kept in the secondary hot cell (East) on the lift table for future beamspot imaging and to cool down prior to disposal.

In their place 12mm Be targets were placed:

• #107 in position 5
• #110 in position 3
• #111 in position 1

We will continue with leak checking and position measurements in the coming week, at which point this ELOG will be updated.

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UPDATE May 24:

• leak testing began on the T1-MK1, vacuum stagnated at 1.5e-2 Torr and a leak rate of 3.9e-07 atm-cc/sec (system vented, will re-tighten target fittings and re-do leak test). 
• after tightening and repeating pump-down in the afternoon, the vacuum volume stalled again at 1.5e-2 Torr. releasing helium to the target fittings registered a response in the leak tester at all virtually locations (for either side of the ladder). 
• the plan for the coming monday is to re-check the vacuum fittings and re-tighten the swage-lok connections to the targets before repeating the leak test once more.

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UPDATE May 27:

• the swage fittings for the targets on position 1,3,5 were tightened in the morning but the volume still couldn't be pumped down to 1e-03 Torr.
• pumping down only on the vacuum line (up to KF elbow ahead of hansen fitting at outlet of target connections pannel) allowed the pressure to drop to 1e-03 Torr so it was determined that the leak tester + associated vacuum connections were not the problem.
• shortly afterwards, we troubleshooted by pumping only to the 'high pressure test' setting (no Turbo pump) and sprayed helium to various joints above the target flange. we learned that there is likely some leaking through the hansen fittings + the swage elbow from the fittings down through the target flange.
• plastic ferrules are used in this elbow to allow for some seals to be replaced, so this may be the source of the leak.
• then, the fittings on the target ladder were re-tightened and helium was sprayed onto various fittings on the ladder. all but the left join on target ladder #1 (position 9a) does not register a leak rate above baseline after tightening.
• at end of day, the ladder was able to consistently reach a base-line leak rate of 1.7e-07 Torr-l/sec and a vacuum of 4e-3 Torr.
• we will proceed with replacing the water line connections on top of the target flange and re-check the leak-tightness of the ladder in the coming days.

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UPDATE June 14:

several attempts at replacing the plastic (Nylon, Swage NY-1013-1 and NY-1014-1) ferrules and re-establishing the fittings on the target service panel were made since the last update. it was determined that the lines leading from the leak detector to the target panel was leak tight (reached 1e-03 Torr within ~5 minutes of pumping down). a double-male Hansen adapter was made to test this (see image). in the final attempt to re-seal, the nylon ferrul-ed fittings were tightened last and the target managed to pump down to 2e-03 Torr, with a stable baseline leak rate of ~2e-08 Torr-L/s. note that prior to exchanging targets, the leak rate obtained during water flushing was 1e-10 Torr-L/sec. additionally, spraying helium on the inlet fittings still registered a response at the leak detector (~4e-6 Torr-L/sec in the worst case).

we think that the following happened to the target, leading to the leak: at some point the target panel collided with something by the water outlet hansen port (see image), this caused the nylon ferrule at that line to crack/become damaged but no leaks occurred immediately after. when we performed the target exchange, the water line was disturbed in some way either as a result of torque-ing the target fittings or when the ladder was moved on the turntable causing the joint to completely fail and leak. because of the damage from the collision, after taking the fittings apart, it is no longer possible to return the fittings and for them to seal.

the plan moving forward is to implement some minor design changes to 1) replace the damaged fittings on the target panel, 2) better facilitate replacement of the nylon ferrules in the future, 3) better facilitate leak testing on the target service panel connections.

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UPDATE Sep 27:

• After designing, releasing, and procuring the leak fix components (see TRH1681), we implemented changes to the electrical barrel connectors and tested the fit of the cooling line piping (see pictures).
• We checked that the ladder motor, potentiometer, and limit switch circuits all worked properly.
• Some differences were noted:
  • D10414-2 accepts 1/4"-20 screws to mount the panel, not 10-24 like shown in the legacy drawings, the clearance hole on TRH1682 had to be adjusted accordingly.
  • The low profile screws specified for the barrel connectors were difficult to use (item 108 in TRH1681), so instead we used normal 4-40 socket head cap screws and were able to check that the barrel connectors could fully couple without interference from the socket head.
  • We did not use lock washers for the barrel connector flanges because they drop too easily and instead we elected to tighten the nuts well.
  • Some loose leads fell out of the potentiometer (bottom left) and profile monitor (bottom right) barrel connectors. These were not electrically connected to anything so we decided to remove them, they will be kept in a recorded location at the end of the operation. 
• In the coming week, we will look to fasten the water line fully and check that they are leak tight.

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UPDATE Oct 02:

• The water line was fastened fully, some items noted:
  • Order of fittings tightened: elbow to bulkhead adapter > elbow to reducer > 5/8" connector to tube > elbow with reducer to tube > nylon ferrule connection
  • We tried to tighten the elbow with reducer to the tubes with the tubes in position to minimize loading the nylon ferrule at the end but found that the outlet tube still ended up protruding significantly from the bulkhead plate (see image). For future operations we should make a note to not load the outlet tube too significantly because it is only supported by the tube (bulkhead nut not fully engaged).
  • The above issue likely resulted from bending the tubes to the 3D printed template but yielding misaligned ends. In the future better templates that emphasize absolute end alignment for tube bending should be made
  • The NPT-Hansen nipple was not tightened before the water line was put on which may have applied unnecessary loads onto the tubes. In the future we will make a note in the drawing on which fittings to tighten first and how to perform the operation to minimize loading on the nylon ferrules
  • In the future some modifications can be made to help relieve this issue for version 2 of the water connections, maybe using flexible metal tubes or thinner walled pipe, alternatively we can implement a more flexible mounting approach for the Hansen ends.
• We noted some tight clearances on the electrical bulkhead. In future implementations of the fix, the connectors can be spaced farther apart or staggered, also they should be moved further down from the top flange of the target ladder.
• Leak testing proceeded with the following results:
  • Total time under vacuum ~2 hours
  • Reached 'fine' vacuum within 1 minute, pressure saturated to 2e-3 Torr within 3 mins 30 secs.
  • Baseline leak rate of 0.0e-10 Torr-L/s reached within 7 minutes of pumping down.
  • ~1.4e-9 Torr-L/s peak @ 15s delay (to first signal) after 1s x 3psi He to general vicinity of newly made water line connections << deemed acceptable
  • 0.5s x 3 psi bursts of He
    • ~0.9e-09 Torr-L/s peak @ 15s delay to nylon ferrule outlet line (did not change after further tightening) < deemed acceptable
    • ~0.2e-10 Torr-L/s peak @ 15s delay to nylon ferrule inlet line < deemed acceptable
    • ~0.5e-10 Torr-L/s peak @ 40s delay to NPT-Hansen outlet < deemed acceptable
    • ~0.4e-10 Torr-L/s peak @ 40s delay to NPT-Hansen inlet < deemed acceptable
  • SS swagelok connections not tested thoroughly due to low likelihood of being a leak source (all tightened properly to 1.25 turns as per swagelok directions)
  • He 'bleed' test by closing hot-cell He wand solenoid valve and bringing wand opening ~5 cm from pos.5 target swagelok resulted in a stable leak rate of 0.8e-8 Torr-L/s << target ladder leak likely prevents pressure in target ladder from bottoming out.
• Will carry on with leak testing the target ladder and possibly the swagelok fittings on top of the hot cell if necessary by the end of the week.

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UPDATE Oct 04:

• The target ladder was pumped down at ~11 am and reached the same baseline as yesterday (0e-10 Torr-L/s @ 2e-3 Torr within 3mins, 30 sec), but in the afternoon, the baseline leak rate worsened to 1.0e-8 Torr-L/s.
• For reference, 0.5s of 3psi He was delivered to the water outlet nylon ferrule joint and registered a response of 1.8e-8 Torr-L/s with a delay of 20 sec. A 3s spray at 3 psi around the water fittings registered a 4.9e-8 Torr-L/s response with a 15s delay.
• The following was observed from sending 0.5s of He to the target ladder Swagelok fittings (see Img for more details):
  • Leak rate baseline improved during testing (~over 1 hour) to 3.0e-9 Torr-L/s
  • Bellows, and targets 2-5 registered leak rates in the order of 1e-8 Torr-L/s
  • Target 1's left Swagelok fitting registered the highest leak rate at 2.8e-7 Torr-L/s (when the leak rate baseline would have dropped to the lowest value of 3.0e-9 Torr-L/s)
• We checked the KF and hansen fittings to make sure that they are not a leak source and managed to bottom out on both the leak rate and pressure readings on the leak tester.
• We will take off Target 1 in the next session, run a die over the male threads, clean the conical face of the male thread with scotchbrite,and attempt to re-do the target joint before leak testing once more.

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UPDATE Oct 11:

• We removed target at pos 1 (ID 111), noticing that the swagelok nuts were easy to undo.
• Working theories on how they became 'loose' include: 1) creep undoing misalignment between the two swagelok tubes on target, 2) vibration from the nuclear ventilation onto the target ladder undoing the joint, 3) thermal changes between summer and 'fall'.
• The threads on pos1 seem worn, it may be a good idea to plug this ladder position permanently to avoid further damaging the threads and jeopardizing the ladder in the future (see image).
• The ferrules on the target seem to be in good condition but we should still clean them with the scotch brite tool
• We added plugs over the exposed male swagelok ports to protect from debris entering the water line.
• We placed the removed target between two wypalls and weighed the wypall down with a wrench to protect it from debris.
• The 3D printed scotch brite tools need to be re-designed for 3/8" drive size (was designed for 1/2" drives).
• We will return to bag, and package the target for safe keeping in the secondary hot cell; clean the male swagelok threads and sealing faces on pos 1 target ladder; and possibly place permanent plugs in pos 1.

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UPDATE Oct 15:

• The leak tester was calibrated with an external calibrator. Original leak rate 1.3e-7 Torr-L/s, 2% loss over ~10 years >> ~1.1 Torr-L/s leak rate.
• The leak checker registered an initial leak rate of ~2.3 Torr-L/s before calibration so we corrected the measurement (at least within the calibration range) by a factor of 2.
• This voids old leak testing data that we made on the target ladder.
• We will add a note to the procedure to ensure that the leak detector has been calibrated before performing leak testing in the future

 ------------------------------------------------------

UPDATE Oct 23:

• After some testing with 3/8" tube Swagelok threads outside of the hot cell, we determined that the reason the threads in pos 1 of the target ladder was 'difficult' to run was likely because the nuts were over-tightened previously.
• There is a risk of compromising the threads if we run the die over over-tightened threads because they have been shifted from where they should be. We will instead attempt to replace the plugs, after cleaning the sealing face on the male threads using the cleaning tools.
• We also checked with a Swagelok tightening gage (3/8) to see whether the other targets were tightened properly, and all had gaps smaller than the gage. Note that we could not get fully into the gap with the gage on the side by the profile/protect monitor due to interference with a support column with the gripper. We will make an extender tool to avoid this issue in the future.
• We also bagged the target that was previously mounted onto pos 1 on the ladder and moved it to the secondary hot cell for storage (temporary).

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UPDATE Oct 24:

• The threads and sealing face on pos 1 were cleaned with scotch brite, blown with compressed air from the inside by connecting compressed air line at the service panel, blown with compressed air from a bottle externally, and wiped with a wypall with the manipulators.
• The old plugs were moved to the secondary hot cell, new plugs were tightened onto pos 1.
• Initially the baseline leak rate was 3.3e-8 Torr-l/s at 4e-3 Torr. With He, we were able to determine that the plugs, specifically position 9a, was the most leaky joint in the ladder.
• After a couple rounds of tightening the plugs, and making sure that the remaining targets were also tight, the baseline improved to 1.7e-9 Torr-l/sec. The plug at position 9a also no longer registered a leak response from having the He line brought up to the joint.
• The plug at position 9a still is the leakiest location in the ladder however, registering a peak leak rate of 2e-8 Torr-l/s at the final baseline.
• We deem that the ladder is sufficiently leak tight, and we will move on to replacing a rubber coupling on top of the target ladder before performing target position measurements.

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UPDATE Nov 25:

• The coupler was successfully removed with a custom puller tool (see TRH1730, TRH1731, TRH1732, and Document-244878). This tool is used for the 3/8" shaft side.
• The press fit coupler had to be cut up with a dremel and saw before using the tool.
• The old coupler had to be 'cut-up' to be removed. During initial troubleshooting, the rubber body split, indicating that it was near end of life.
• The replacement coupler system could be inserted without removing any parts.
• The relative alignment of the shafts may have changed up to 1/2 a turn during this process (the printed clamps were not strong enough to resist torques exerted when attempting to remove the press fit coupler).
• Potentiometer table will need to be reviewed when performing target measurements.
• Light loctite to be added to the treads.
• Note: the old coupler has stainless shaft adapter (3/8" step down).

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UPDATE Nov 28:

• Loctite added to all coupler screws (including flexible coupling from motor to three-way gearbox)
• Final leak check completed on replacement piping on service panel with the following results
  • baseline leak rate bottomed to 0.0e-10 Torr-L/sec within 7 mins and pressure bottomed to 1e-3 Torr within 5 mins.
  • baseline leak rate worsened to around 1e-9 Torr-L/sec by the end of leak testing, assumed due to increase in amount of trapped He in the line through testing
  • (time to detect [s] || peak leak rate [Torr-L/sec]) values for 3psi, 0.5s Helium using wand on top of hot cell
    • inlet side:
      • 20s || 3.8e-10 for nylon ferrule joint
      • 20s || 6.3e-10 for o-ring flange
      • 20s || 2.7e-10 for hansen NPT thread
    • outlet side:
      • 15s || 3.5e-10 for plastic ferrule joint
      • 15s || 5.1e-10 for o-ring flange
      • 20s || 0.8e-9 for hansen NPT thread

The target ladder was moved to the lift table in preparation for measurements.

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UPDATE Jan 03, 2025:

• Measurements (elevations) of the targets and alignment jig were completed over December to early January.
• Notes on measurement procedure:
  • Used the old alignment jig instead of new (easier to insert/remove)
  • Noticed that the target ladder potentiometer is jumpy at around 12 kOhm
  • Placed the jig between positions 4-5 throughout (pot reading of 11.65 kOhm places the jig in beam height - in line with protect monitor)
  • For left-right measurements, moved the alignment jig 'into-position' (i.e. set potentiometer value to 11.65 kOhm) to 'zero' the micrometer before changing ladder position (potentiometer value) back to the target being measured (turntable height not touched after zero-ing off to the jig)
    • For the entry side, because the protect monitor is obstructing, target 5 had to be measured above the protect monitor (jig also zeroed off above the protect monitor, i.e. not at the resistance value given above), while all other targets were measured below.
    • This introduces some error since we are measuring the target not in the beam position.
  • Target height measurements were done with measuring tape as normal.
  • Targets were measured with turntable flange having an angle of ~0.2 degrees, plumb bob and jig measurements taken with turntable flange 'leveled' as best as possible (angle of ~0.02 degrees)
    • For future measurements, the turntable should be also leveled before target measurements.
  • Levelling the turntable flange was done with a Digi-pass digital level (DW-1300XY, in absolute level mode, calibrated before starting)
  • By the cutout, the turntable flange is less stiff, causing level measurements to be tilted inward. We therefore relied more on level measurements on solid portions of the turntable flange as well as on the target flange.
  • Levelling bolts could be turned with target ladder seated.
  • If the turntable is not rotated, and only raised/lowered, the levelness of the table and target remained approximately constant (e.g. from 0.02 degrees change to 0.04 degrees as the turntable is lowered fully from fully raised).
  • If rotated, the turntable level changes significantly (e.g. from 0.02 degrees to 0.15 degrees)
  • The flange was re-levelled between entry side and exit side measurements for the plumb bob and alignment jig measurements
  • With new nuclear ventilation filters, flow inside the hot cell perturbs the plumb bobs and prevents them from settling.
  • Nuclear ventilation had to be turned off momentarily for the plumb bob measurements
  • Nuclear ventilation is returned when working on the hot cell roof
  • Nuclear ventilation is controlled by turning the toggle on the electrical disconnect panel from 'hand' to 'off' ('auto' setting assumed not used)
  • Respirator and lab coat worn throughout plumb bob measurement job, air survey done by RPG after job (confirmed OK)
  • Area also 'taped off' during plumb bob measurements to prevent non-worker entry
• The coupler exchange resulted in around a 0.4mm shift in the target heights
• A shoulder screw and wood clamp is used to lock the plumb bob jig in place (old screw/nut missing, no other components in toolbox provides locating fit for pivot joint on jig)
• Assumed new plumb bob measurements more accurate due to better/more accurate 'levelling' equipment (digital level).

 Between Nov 14 ~ Dec 9 the following activities took place:

- The leaky 10mm Be target at pos'n 3 was removed and plugged
- The loose protect monitor electrical conduit was secured in place using an aluminum shim
- David Cameron performed an electrical check on the protect and profile monitors and got the expected response from both
- The target was flushed with water, then air
- The target was pumped down using a cold trap to capture remaining moisture
- The target reached a minimum pressure of 80mTorr on the leak detector Hastings gauge
- Helium leak check revealed a leak at both of the position 1 Swagelok caps (up to 80 on 50x scale on left side, and 100 on 100x scale on right side when facing ladder with 1s spray of 5psi helium)
- The leak rate did not improve with tightening of the caps
- The caps were removed, ladder side threads inspected (no obvious damage observed), and new caps installed
- Helium leak check repeated: Pos'n 1 left side now leak tight, right side leak rate was worse (could not completely open throttle valve on leak detector)
- Torque was increased on the cap with no improvement in leak rate
- The right side cap was removed and when trying a new cap it would not spin freely
- The ladder side threads were inspected more carefully with the Nikon level:  a small dent across the first thread at approximately 2 o'clock position was seen as well as some material build-up or possible galling seen at the 1st and 2nd threads around the 4 o'clock position.
- The threads were filed to improve their profile which allowed a new cap to be installed with light resistance (still would not spin freely)
- Leak check was performed with a minimum pressure of 70mTorr reached (throttle valve fully open, roughing closed), with large response still at the right side pos'n 1 cap, No change with moderate tightening

It is suspected that the ladder side fitting sealing face is damaged causing a poor seal.  When a cap was installed and torqued this may have caused the galling or material build up observed at the 4 o'clock position (but not the dent on the 1st thread at the 2 o'clock position)

Various experts on-site will be consulted about how to best proceed before doing further work.  One option is to perform a static water test.  If the target is water leak tight then it may be used in the beam line.  If repair efforts are not successful and the target is not water leak tight then the target ladder will have to be replaced which is approximately a 2 week job.

 The T1-MK1 target is currently in the hot cell for repair of a leak at position 1.  See E-Log #129 for details on previous work.

- Pos'n 1 right nut removed (a little stiff, but no excessive force required)
- Exterior threads cleaned w/ Scotchbrite disc on Dremel tool
- Inside sealing face inspected w/ Nikon level.  Possible brownish material on sealing face at 10 o'clock and 12/1 o'clock positions
- Threads inspected w/ Nikon level: small dent at 1st thread 2 o'clock position as seen before and small amount of material build-up or galling at 1st & 2nd thread 4 o'clock position.  Otherwise threads looked clean and straight
- Constructed Dremel attachment using ~1/2" thick, ~4" long piece of Scotchbrite folded over a 1/16" diameter steel rod, secured with zap-straps and shaped w/ scissors to fit inside the ladder port (see photo)
- Cleaned and polished the sealing surface w/ new Scotchbrite Dremel tool
- Inspected inside sealing surface: brown coloured material no longer visible.  A clear scratch/dent is visible at 10 o'clock position.
- Blew out hole and new nut with compressed air
- Installed nut (went on much easier than before which indicates that the Scotchbrite disc thread cleaning method is effective)
- Leak check performed:  pumped down to ~70mTorr on Hastings gauge w/ throttle valve fully open and roughing valve closed
- Sizeable leak at Pos'n 1 right side nut, as before.  No improvement with tightening

The next step will be to perform a static water test on the cooling lines to see if the plug is water leak tight.  If it is, no further action is necessary.  If not, either the ladder must be replaced, or other methods to achieve a seal investigated.