The T2-MK2 target in the hot cell was flushed with water and then purged with air so that stagnant water is not left sitting in the target.  Replacement of the failed 10cm Be cassette will take place in January 2014.

 The leaking 10cm Be target was removed from position 3 on the T2-MK2 target ladder and the water ports were blanked-off with 3/8" Swagelok plugs.  A 10cm Be target remains in position 4.  The target was pumped down using the cold trap and a helium leak check was performed.  All target locations on the ladder were found to be leak tight.  The delta seal locations and fittings above the vacuum flange were also leak tight, however small leaks were discovered at the weld at the lower end of each bellows, details below.

Using the old leak detector in the Meson Hall HC Lab, at baseline level 18 on 10X scale with the target oriented as when installed in the beamline, using 1/2 second application of helium at ~3psi:
East side bellows: response up to 90 on 10X scale, returned to baseline in ~5s
West side bellows: response up to 30 on 50X scale, returned to baseline in ~5s

Based on previous helium leaks of this size it is expected that the bellows are still water leak tight.  Replacement of the bellows will not be considered unless a water leak is found.

After an electrical check is performed on the profile monitor by Probes Group, this target will be returned to the beam line and pumped down to check for water leaks.  If water leak tight, the T2-MK2 target will be used for operation in 2014.
 

Photos are attached of the failed 10cm Be target, as well as the T2-MK2 target assembly with leak locations indicated.

 An electrical check was performed on the T2-MK2 profile monitor by Bill Rawnsley.  All signals produced the expected response, and Bill approved the monitor for use.  Bill has saved screenshots of the signal profile.

The target ladder position micro-switches and profile monitor in/out limit switches were also tested: all OK.

The T2-MK2 target is now ready to be transported to the beam line.

Water was purged from the T1 and T2 targets using compressed air.  The water is stored in a labeled bucket on the BL1A blocks near the T2 cooling package.  The bucket is approximately 100µSv/hr on contact and 10µSv/hr at 0.5m.  Isaac's coveralls had 500cpm on them after this job and were dropped off at active laundry.  Keith had no contamination on his coveralls.

The T2-MK1 target was moved from the beam line to the target storage pit in position 4.  The target was measured to be 30mSv/hr at 0.5m.  The move went smoothly.

The T2-MK2 target was then moved from the hot cell to the beam line.  The target was 151mSv/hr at 0.5m.  For reasons unknown the target was slightly out of rotation when lowered into the beam line, and could not be fully lowered because the alignment pins were out of position.  It was not possible to twist the target while it was supported by the flask, so 2" aluminum standoffs were placed on the monolith flange, and the target was lowered onto the standoffs.  The target was then lifted without using the flask, the standoffs removed, the target rotated to match the locating pins and then lowered onto the flange.  It is possible to adjust the rotation of the lift T flange on this target if the misalignment is found to be caused by the target and not the flange.

The new target information sheet was delivered to Ops, and XTPAGE 7L was updated.  Graham Waters was notified of the change so that he can update the potentiometer look-up values in the control system.

The target flask catch tray was cleaned using a wet wipe which had 11,000cpm on the 44-2 meter and 300cpm on the RM14 meter.  After cleaning, a dry swipe of the tray inside had 0 counts on the 44-2 and 100cpm RM14.

300cpm contamination was found on Isaac's coveralls and 150 on Ron's.  There was 6000cpm found on Ron's booties.  He had been working on the blocks around the T2 monolith, but had not been down to the monolith itself.  A request will be made for Plant Group to paint the blocks around the T2 monolith.

 The T2 Protect Monitor was transported from the beam line to the hot cell this morning using the transport flask.  The move went smoothly.  The only difficulty was locating the yellow flask alignment frame to the T2 monolith as the T2 protect holes on the yellow frame are tighter than for other devices.  It was necessary to remove four screws that secure the top flange of the T2 protect monitor assembly to the flange on the monolith.  These screws are stored on the top of the monolith in a labelled bag.  The T2 protect o-ring was in good condition, but was replaced anyways, and a blank-off was installed over the hole so that vacuum can be pulled on the T2 volume.  A maximum field of 15mSv/hr was measured at 0.5m from the monitor while lifting.

Probes Group may now begin testing / repair of the monitor.  Bill Rawnsley has been notified.

Photos attached.

Update (March 19, 2014):  Bill Rawnsley thinks that the damage was caused by mis-steered beam (not from water).  He points to the evidence of heating in the attached photo.

After the monitor assembly was moved to the hot cell, electrical checks were performed by Bill Rawnsley which showed the same results as when tested in the beam line.  A new monitor was installed (supplied by Probes Group), the tests were repeated, with all results appearing normal.  The monitor assembly was transported to the beam line this morning and installed at the T2 monolith.  All cables were attached and the flange was bolted down.

Bill was notified by e-mail and it was suggested that he perform one final electrical check from the mezzanine before the monolith is covered.

The T2 profile monitor cannot be actuated from the control room.  When the solenoid valve that supplies air to the air cylinders is powered directly, the monitor moves in normally, therefore a controls issues is suspected.

Additionally the monitor position shows neither IN nor OUT.  This does not change when the monitor is at either limit.  Proper actuation of the target micro-switches has been confirmed.  The T2-MK2 target is currently installed, but this was also an issue in Nov/Dec 2013 with the T2-MK1 target installed.

Fault report #7276 has been filed, targeted at Cyclotron Controls Group.

T2 Profile Monitor actuation was tested today from the control room and all is working properly.  The position (IN / OUT) also displays correctly.
To my knowledge nobody has looked at this system, so it is a mystery why it suddenly started working.  This e-log will be updated if any explanation is found.

Actuation of the M20 beam blocker and T1 Profile Monitor were also tested and are working as expected.

The T2 monolith may now be covered.

Update:  A blown fuse in the control racks was replaced yesterday by Dave Cameron, which explains the change.

The T2-MK2 target (currently installed in the beamline) was moved from position 0 to position 4 (10cm Be) using the portable control box.
The T2 cooling package was started after moving the ladder.

There was no change in the BL1A vacuum.  The T2 expansion tank water level dropped slightly, as expected (around 1/16"), and was refilled to ~1/4" above the high level sensor top nut.

30 micro-amps of beam was put down BL1A and the T2 target and cooling system appear to be functioning normally.

When beam was started in mid-April, it was observed by Operations Group that with the beam centered vertically within the protect monitor, the profile monitor showed the beam spot to be approximately 6mm high.  The protect monitor was changed during the shut-down due to a failure in November 2013, so it was suspected that the new protect monitor was not aligned properly.  The beam spot appeared to be dangerously close to the top weld of the target window so it was decided the target assembly would be removed for inspection to visually confirm the suspected misalignment before increasing beam current.  Since start-up, a maximum beam current of approximately 30 micro-amps had been used on the 10cm beryllium target in position 4 which previously had not seen beam.

On Monday April 28th, the T2-MK2 target was transported from the beam line to the hot cell.   The target assembly was measured to be 298mSv/hr at 0.5m.  A clear beam spot was visible on the entrance and exit windows of the target approximately 6mm high of vertical center (photos attached).  Target and profile monitor elevation measurements were conducted, and confirmed those previously taken on the target by Tom Lyth.  This exercise confirmed that the position 4 target and profile monitor were aligned properly, and that misalignment of the protect monitor was the cause of the beam being high on the target.  It was then decided that the protect monitor assembly would be removed and a new monitor cassette installed to remedy the problem.

On Wednesday April 30th the T2-MK2 target was returned to the beam line and the protect monitor assembly was transported to the hot cell.  A maximum field of 15mSv/hr at 0.5m from the protect monitor was measured.  Elevation of the monitor cassette was checked, and was found to be 6.8mm above the elevation of the position 4 target.  The monitor cassette was removed from the assembly.  The cassette was approximately 100μSv/hr at 0.5m and 2mSv/hr on contact, with 200cpm measured from a swipe of the outside surfaces (not the inside plates).  The cassette was returned to Probes Group for possible use in the future.  A new monitor assembly was supplied by Scott Kellog on Friday morning with the 6.8mm adjustment.   The monitor was installed on the protect monitor assembly.  Elevation was checked and found to be within 0.5mm of the target elevation.  After installation an electrical check was performed by Dave Cameron and Mike Russel.

The protect monitor assembly is ready for installation in the beam line on Monday morning.

The T2 protect monitor was returned to the beam line using the shielded flask.  The alignment pin did not align with the hole in the vacuum flange, but could be aligned by hand by rotating the monitor assembly while it was hanging from the flange.  The protect monitor vacuum flange was bolted down and all services connected.  The T2 protect and profile monitors were checked by Dave Cameron (both OK).  Vacuum was pumped down and the cooling package started without incident.  After installation of the cap block the M20 beam blocker and the T2 profile monitor were exercised (both OK).  The updated target info, elevations, and beam spot measurements were delivered to the control room operators.

While the monolith was exposed the T2-MK2 target assembly lift hat was rotated slightly to match the orientation of T2 Protect and Col. A.  Hopefully this will improve the alignment for the next time the target is lifted with the flask.

The T2 target was exercised to position 0 around 6:15pm so that the T2 profile monitor could be used by operations.  The T2 water package was re-enabled when the target was in position 0, however this resulted in some trips of the cooling package.

Operations called around 7:45 to request return of the target to about 2mm above position 4.

The target position was re-set so that the position reading fluctuated roughly between 2.7 and 1.6 mm above position 4 (hovering roughly around 2.0 mm), and so the potentiometer reading was hovering roughly between 0.801 and 0.798.

The cooling package was re-started, and called operations to confirm the system was OK.

The T2 target was moved from Position 4 to Position 0 at 11:15am so the profile monitor could be used during the development shift.

The T2 cooling package tripped regularly throughout the day on high flow while in position 0.

At 10:45pm the T2 target was returned to the previous running position: approximately 2mm above the nominal position 4 elevation (pot ratio fluctuating slightly around 0.799) so that beam could be run overnight.

 - 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)

 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-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.

 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.
 

This is a continuation of work detailed in E-Log #129 and #140.

- Static water test performed on the target cooling lines:
     - Test setup assembled and leak checked by pressurising with house air, submerging in water and checking for bubbles (see photos)
     - System filled, pressurized, and valved off on Friday Feb 13 at 5:30pm,  Gauge read 60psi
     - Checked Monday Feb 16 @ 9:00am.  Gauge read 56psi
     - Checked Monday Feb 16 @ 5:00pm.  Gauge read 56psi
     - Checked Tuesday Feb 17 @ 9:30am.  Gauge read 55.5psi  (0.5psi / 24hrs rate)

- Checked results with Dimo and he requested a helium leak check be performed with a newer model leak detector to quantify leak rate:
     - Using Varian 979 leak detector, pumped ~1.5hrs w/ cold trap to remove water
     - TP press: 0.0*10^-4 torr,  Base leak rate ~7.0*10^-9 atm cc / sec
     - Tested all normal leak check locations and did general helium flood with no response at all  (1.5psi helium pressure)
     - Over ~ 20 minute period the base leak rate gradually rose to 8.8*10^-9 atm cc / sec, at one point spiked to high 10^-9 level, then returned to base line
     - Reviewed results with Dimo, he requested test be repeated after the target sits vented overnight

- Target vented and left overnight, leak check repeated Feb 18 starting 9am:
     - 0.0*10^-4 torr TP pressure after ~5 mins
     - 10^-9 atm cc / sec leak rate level after ~20 mins
     - All locations sprayed with 1.5psi helium, general flood in ladder area --> no response (Dimo and Edi present)
     - Target deemed OK for use in beam line by Dimo, he requested the cooling lines be filled with helium after installation in b/l while leak checking T1 volume

- Target will be transported to the storage pit tomorrow (Feb 19) and is ready for use as the spare T1 target

The target had an obvious helium leak when first tested (E-Log #129 and #140), which could not be found when helium leak checking again after the static water test.  Some possible explanations are:  water remaining in the lines blocked the leak path,  water remaining in the lines froze when vacuum was pulled blocking the leak path, having water in the lines caused some corrosion or other deposit which plugged the leak.

The helium leak at plugged position 1 right side measured before the static water test is the same, or slightly less than the leak rate when the target was first removed from the beam line.  There were no T1 vacuum issues during the running period, therefore no issues are expected when this target is put in service again.

- The T1-MK1 target was moved from the hot cell to storage pit hole #3 (ready as T1 spare)

- The T2-MK2 target was moved from the beam line to the hot cell for inspection and in preparation for T2/M9 work this shutdown
- The target measured up to 90mSv/hr at approximately 1m while being lifted
- Beam spots on the target will be measured and recorded to determine ideal offset (if any) for next running period
- A 10mSv/hr collimated field was measured coming from the T2 monolith hole
- An aluminum blank-off was installed over the hole followed by a stack of circular steel discs for shielding which reduced the max field in the area to 700uSv/hr