Tower Disassembly

Tower disassembly is fairly intuitive. The following is a step-by-step proce- dure for disassembling the tower and removing a detector.

1. Unscrew the adapter plate located at the bottom of the side coaxes and remove it, taking care at the position where the thermometer wire passes through it. Store this in the purge cabinet.
2. To remove each position 1 side coax, repeat the following steps:
   1. Unscrew the long screws that fasten the side coax to the tower. Face 2 will only have one screw as one of the holes in the tower is blocked. You may require tweezers to pull them out once they are loose. Store these in the purge cabinet. Be careful when removing the screws that pass through the SCUHBA extender plug with the copper spacer as it may fall off.
   2. Gently coerce each side coax off the tower. You may have to wiggle the side coax off. Use both hands to wiggle pins out off both sets of sockets at the same time to avoid bending them or damaging the sockets.
   3. Do not worry about removing the SCUHBA extender plug at the same time. If the SCUHBA extender plug is attached to the side coax, remove it. Some gentle persuasion may be required. If the SCUHBA extender plug is still on the tower, gently wiggle it off. Store the SCUHBA extender plugs in the purge cabinet.
   4. Remove the protector boards from the purge cabinet and place them on the clean bench. Cover the exposed pins on the side coax with these boards.
3. Store the side coaxes in the purge cabinet.

1. Peel off the pieces of kapton and copper tape holding the thermometer wire to the spool, and detector and source housings.
2. Remove the tower from its aluminium holder and place it upright on the clean bench.
3. Remove the six M2 threaded rods that pass through the top lid, and detector and source housings. Each rod features two nuts protruding from the top lid. Keeping the nuts together will aid you in your task. Use your other hand to support the tower by grabbing onto the spool while doing this. It is prudent to always support the tower while it is upright on the clean bench. Place the threaded rods in the purge cabinet.
4. The stack is now loose, so take care when performing the next few steps as one false move will cause the detector to drop off the tower. Remove the top lid and place this on the clean bench. You will need this when preparing the detector for shipment.
5. Gently lift off the source holder, keeping your fingers clear of the detectors DIBs and wire bonds, and place it in the purge cabinet.

1. Remove the connector lid with two pieces of kapton tape covering six holes from the purge cabinet. Place it on the clean bench.
2. Carefully lift the detector off the tower, keeping your fingers clear of its DIBs and wire bonds, and gently place it on the connector lid you just removed from the purge cabinet. Do this all in one motion. Try to lift and lower the detector as straight as possible. Do not worry too much if the mating is not perfect and you need to slide the detector a little. As long as you are gentle, this is perfectly acceptable.
3. Carefully lower the top lid you removed from the stack in the previous section onto the detector housing, keeping your fingers clear of its DIBs and wire bonds. You can do steps 2 and 3 in either order.
4. Carefully lower the top lid you removed from the stack in Section 1.2 onto the detector housing, keeping your fingers clear of its DIBs and wire bonds. You can do steps 2 and 3 in either order.
5. Remove a dozen M2 brass Phillips-head screws from the purge cabinet and place them on the clean bench. There are extra screws in the first drawer of the tool cabinet.
6. Use these screws to fasten the lids to the detector housing. They should screw in; if not, you are using the wrong hole. It is very easy to strip their heads, so inspect their heads beforehand replacing any that look dodgy to you, and do not force them in. When in doubt, throw them out: they are very cheap. If you find one gives you a bit of resistance, remove it and try again. Do not torque these screws. They do not have to be tight; simply well-seated will suffice. You may not be able to insert all the screws in every hole as the hole itself may be stripped. Dont worry, this is expected. As long as you have enough screws (usually three) to hold the lids in place, this will suffice. Screw both lids to the detector housing.
7. Take 6 threaded rods, that are shorter than the ones that held the stack together that you removed in the previous section and feature a nut soldered on one end, from the purge cabinet and place them on the clean bench.
8. Insert these rods from the top, through the top lid and detector housing. With ease, they should fall through and hit the connector lid. You may need to gently shake them a little while threading them through. If you come across resistance, you have inserted them in the wrong holes.
9. Screw the rods into the connector lid. This secures the lids and housings together to form a stack. Use the socket driver (there are two of them in the clean room). They should be finger tight and there is no need to torque them. Ensure that the lids and housing are secure, ie. they do not move. If they do move, you must tighten the screws further. Do not force the threaded rods in. If you feel resistance, remove it and try again.
10. If there is any residue from the tape on the detector housing or top lid, remove it by gently wiping the surface with an isopropanol or methanol soaked wipe. Stay clear of the DIBs; you shouldn't have to go anywhere near them.
11. Conduct a detector level continuity check as detailed in Table 1. After sending the detector to Stanford, the measured values should be recorded on the Detector Elog. For now, the values can be recorded on the run diary. You should compare this with previous measurements.
12. Place the crystal in the purge cabinet. The crystal is ready to package for shipment.

The tower should be placed back in the purge cabinet. If supported, the tower can rest on its side with the connector lid attached. However, you might remove the connector lid to place spacers between it and the spool when assembling the tower with some detectors.

1. Turn the tower upside down so that the connector lid lies on the clean bench.
2. Use the right-angle screwdriver to unfasten the M3 brass screws holding the connector lid to the spool. Take care not to strip the screw heads. Brass is softer than the steel tip of your screwdriver, so this is very easy to do. If you feel as though you will strip the screw, stop and try again at a different angle or pressure.
3. If you do end up stripping a screw head, or find that one of the heads is stripped, do not panic. You can try to unfasten the screw with a pair of pliers. Try your level best not to scratch the spool while doing this.
4. Place the tower, connector lid and M3 brass screws in the purge cabinet. Throw away any M3 screws with damaged heads.