23/09/02

Handling tool for mounting modules in the rods
Bill G. has designed and realized a tool to handle modules and install them in the rod. The module is held from the hybrid side, close to the holes that have to fit the locating dowels. This is the region where some pressure has to be applied during the installation. Antti suggests to increase the width to go over the module support blocks, so as to avoid that the edge of the module (on the hybrid side) might be pushed lower than its nominal position. Here is the drawing of the tool, explanations from Bill, and some pictures showing the tool in action.

Screw-driver for mounting modules in the rods
Bill G. shows a dedicated screw-driver that carries safely the screw and the washer over the module. Here is the drawing and the explanations from Bill.

Bending of the HV legs and hybrid cables
There are two types of bending for the HV leg and two types of bending for the hybrid cable, depending on the way the module is mounted in the rod (see these drawings). The hybrid cable, and even more the HV leg, tend to relax after they are bent, so it is advisable to do the bending as late as possible, just before the installation of the module in the rod. Bill G. found that heating the bending tool improves marginally the result, up to relatively high temperatures (100oC). Going to higher temperatures could cause problems to the resin, therefore his advice is to do a cold bending, just before the installation. For the HV leg, in the case where the kapton has to go over the connector (case one in the drawing tob_module_hv_kaptons.gif) it might be a good idea to add a drop of glue between the connector and the kapton, after the bending. Once the module is installed, the cable (or HV leg) is constrained in a stable position, and no problem is expected to arise. The validity of the bending tool has to be verified in the locations of the rod where the space between the module and the IC card is tighter (modules 3 and 5 in rods of type "low") for both mountings. The bending tool will be developed in the US. Here is a drawing from Bill showing the bending sequence, with some explanations.

Transport boxes
Rod transportation will happen as follows:
Rod mechanical structures from Helsinki to CERN
Cabled rods from CERN to FNAL and from CERN to UCSB
Complete rods from UCSB to FNAL
Complete rods, after burn-in, From FNAL to CERN.
In FNAL the transportation boxes will be used also during the tests: rods will be thermal-cycled in the cold box while sitting in their Aluminium transport box. This places new requirements on the boxes. The result of the discussion is the following:
1. Shortening the box sounds dangerous. The box should include the CRTL cable, that sticks out by about 150 mm from the end panel. The cable could be folded and the CTRL-out connector engaged with the CTRL-in connector of the same rod: this would reduce the additional length to less than 100 mm, on the other hand (dis)engaging these Binder connectors requires a lot of pressure, and it is maybe better to avoid all connections that can be avoided.
2. The problems of the electrical and optical connections may be solved by hinging the cover on one side. It remains to be verified that the clearance between the rod and the other cover (the one that is not hinged) is enough to (dis)engage easily the electrical connectors.
3. The rod has to be insulated electrically from the box. Most likely the "foamy" clamps holding the frame already do the job. The box has to be then put to ground.
4. Requirements previously discussed remain valid (improve the clamps, introduce z-stoppers, rubber feet for the box, increase width, smooth edges).
At CERN so far the possibility of testing rods inside the transport boxes was not considered, as this was not possible with the design as it was up to now. Advantages and disadvantages will be now considered, so that a decision is taken by the time the new version of the drawings are made available (the choice has implications on the total number of boxes needed).