Photos compiled in pdf, download to view in case ELOG preview truncates.

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

The HV shield covering the beam dump, on the peripheral side of the FE plate was taken off an on successfully with the manipulators:

• The operation was completed without reorienting the FE towards the HC window and we were still able to perform the removal/installation operations.

The 'helmet' shield on top of the FE plate was successfully exchanged:

• Rough steps: pull the helmet up and back to release from its seated position
• Both manipulators used during operation
• The threaded hole to install grabbing features has 'fine pitch' threads
• Fortunately we were able to replace this shield without the need for additional handling features
• We moved the helmet out towards the gamma dump direction, but to prevent scraping against ceramic standoffs it may be a good idea to pull out the helmet shield from the other direction, though there's an elevated dropping risk (drop onto service tray) and the manipulators will have to reach farther in
• The exchange test was completed with the FE plate facing parallel with the HC window, in practice we would like to reorient the FE maybe 15 degrees CW from this orientation
• Rotating the FE slightly will help with some interference between the left manipulator arm and the shield plug (see photo)
• Adjacent VCR lines may interfere with reinsertion if not done up

HVFT shield was picked up successfully with two manipulators without much issue:

• Found that the manipulator handling cutout on the shields was a bit too large, a smaller gap across the width of the fingers will make is less necessary to grip tightly to keep the shield in line with the gripper
• The above observation applies generally to all HV shielding cutouts
• captive screws where possible on the HV shielding is generally a good idea, the screw on this shield could be captive

The HV shield obstructing exchange of a VCR gasket on the driver side was removed with issues:

• Access to button head screws obstructed by ceramic cylinder, risk of damaging cylinder when accessing these screws with tool, to prevent damage should move position of screws farther away
• Far screw difficult to see from operator window
• Raising the turntable/FE up helps with access
• Remote camera view helpful but due to location, difficult to get head on view of the screws for checking key engagement
• Caveat: ceramic standoffs that would have further obstructed the screws were not installed (final picture)
• Changing design to incorporate slots into the screw holes, similar to the gamma dump HV shield would be greatly beneficial
• Alternatively mount to standoffs to a different plate or add an intermediate adapter plate to make removal and installation of this HV shield easier.

Service tray HV shield on multi-pin connector cable side was tested:

• Existing shield has protrustion that prevents engagement with threaded standoffs and cannot be installed
• Some change required for this HV shield

We did not test the HV shields by the KF clamps for the extraction electrode, we will assume that the KF joint will be made serviceable without needing to remove the shielding and that the VCR joint by that area will never need to be serviced.

Testing on other HV shields to resume in following session.

 ------------------

UPDATE April 09:

We ran into some issues turning the East and West turntables.

We tested mounting the service tray shielding by hand and foresee no issues.

The shielding covering the rear busbar connection with ribbon connector by the water service lines to the HTV was tested by hand:

• There are no locating features to position this shield where it needs to be screwed down.
• The mounting screws (mount to FE) should be made captive. or employ a similar approach as the ionization dump shielding (slots in and keeps the shielding in place)
• The threaded holes for mounting grabbing features could be improved by adding additional locating features to 'clock' the grabbing features in the desired orientation, without needing to torque down the screw.
• The above recommendations apply to all shielding as appropriate.

 ------------------

UPDATE Apr 20:

After the East and West turntables were fixed, we were able to test the removal and replacement of the HV shield covering the rear busbar connection (ATA3540).

• 3D printed H-handles were attached to both grabbing feature holes on the shield
• The H-handles rotated with ease despite the screws being moderately tightened, making rotational positioning of the shield difficult
• It may also be a good idea to add a slight angle to the H-profile on the handles to better clear the manipulator wrist from interfering with other FE structures (see photo)
• The air ratchet was used with a short socket key to remove the screws on the shielding
• FE rotated such that the non-gate valve side opening faces the hot cell window
• The FE was not raised far enough and prevented the left manipulator from accessing the second 3D printed h-handle on the gate-valve-side opening
• When removing, there was no need to keep the shielding retained since it could not 'drop' and damage anything
• When returning, it was difficult to tell whether the shield was seated properly, may
  
  • The shield does not stay engaged on the mating nubs on the FE without the screws tightened
  • Returning the shield onto the FE will likely require two manipulators: one to keep it in place, another to reinsert the screw
  • We would strongly recommend changing the screws on this shield to be captive since dropping a screw in this location will cause it to be stuck deep in the service tray
  • Also, if the mounting design could be modified such that the shield stays put when in place and does not drop, it would be a great help
    • some ideas: substituting One of the screws with a pin, having the slot design that's present on some of the other HV shields, or adding more locating features in the mating interface
• When doing-up the screws, with the air ratchet (or smaller electrical tool in the future), it was relatively easy for the tool to slip and turn onto the ceramic components.
• In the real deal, it is imperative for protective impact covers to be placed over the ceramics first.

We tested removal and returning the patch panel shielding by hand:

• the main thing to note would be that the manipulator handle to be installed may need to be made horizontal with side access