LST Module Installation Mechanical Design Review William Sands, Princeton University, 10-22-03

Installation Procedure Overview 1) Installation takes place from the forward end using positioning apparatus designed for RPC removal. 2) The Z-strip is installed first with connectors toward the backward end. 3) Module is installed HV end toward backward end with utility tray fastened. 4) HV and gas lines are installed to module. 5) Next module installed and gas lines daisy chained from first module and HV plug installed. 6) When enough modules are in place so that the last will protrude from the backward corner plate the modules can be slide behind the corner plate. 7) Procedure continues until layer is full.

Z-Strips The Z-Strips are placed in each layer prior to the modules. The readout connectors are positioned between the center gap plates on the four side sextants and straddle the center gap plate on the top and bottom sextants.

Utility Trays The utility trays are installed on the module prior to sliding the module into a layer. The trays are used to organize the routing of cables and gas lines out of the layers.

Module Installation The modules will be installed by positioning the H-Box on the RPC removal apparatus and sliding the modules into the appropriate layers. When the modules are installed from one side of the box the top can be replaced and the box flipped to access the other side.

Forward End Facing North The forward end where the Z-strips and modules are installed will have the corner plates and center gap plates removed. Full access to the layers in the forward end will allow for a much more controlled installation and is necessary to fit the Z-strips which are full width.

Forward End Facing East For installation of the bottom sextant we have some obstructions with the concrete pier and structural apparatus shown below. The pier is approximately 161” from the steel and points on the structure come as close as 60”. Installation can be accomplished by installing some modules on an angle and then sliding them over.

Backward End Facing South From the backward end the gas lines , Z-Strip readout and HV lines will exit the layers between the gap plates. The gap plates will be removed for installation except in the bottom sextant where the DIRC prevents removal. The Phi readout will exit through the forward end except in layer 18 where all utilities must be routed through the forward end where there is no access to the backward end.

Cable Routing Cables and gas lines will be routed toward the opening at the center gap plates in the utility trays as shown below. Gas lines will be connected from one module to the next as they are slide to the corners, work will be done from the corners to the center where the bundles will enter a conduit to rout to the electronics and gas huts. Layer 17 and 18 contain 10 modules each which have the most utilities from each sextant to be routed. In the trays 5 modules will be routed from each side containing an input and output gas line and 5 HV lines along with grounds.

Daily Plan Each day in two shifts the plan is to install one layer or more if possible. A third quality control shift then comes on tests the modules each day. If a problem is found the first task the next day is to replace the faulty module and then move on to the next installations. It has been found that tube can sometimes be repaired, if this is the case the module will be used as a spare or installed in another sextant at a later date.