The LPTPC Desy readout module
This wiki contains the evolving development notes about the DESY GEM readout module for the LPTPC. The sub-pages are always work-in-progress and will mirror the designing process. This page are not meant for publishing or for external consultation but for internal documentation.
The readout module of the Large Prototype is a cornerstone shaped detector element that can be installed in the LP endplate. It can be used to test different technologies for gas amplification, readout, and electronic acquisition and elaboration. We decided to develop our module using a GEM based gas amplification system, a traditional pad readout and the ALTRO electronic system for data acquisition. The electronic system is develop and maintained in LUND.
The module itself is composed of four main elements:
An aluminum back-frame that is used to mount and align all the other elements and provides gas tightness to the assembly.
The anode-side pad readout board with a ~5000 channel segmented pad plane. On the TPC side of the board there are also 20 power pads to provide the bias voltage for the GEMs. All the connectors are placed on the external side of the board.
The GEMs are the active electron amplification element used in this module. They are designed together with the ceramic support structure to cover the largest possible area of the module with the least amount of material and dead areas.
A supporting system for the GEMs to keep them flat and stable in their designated position while reducing the dead areas and the material budget of the detector.
After the completion of the design phase the module elements are going to be produced and delivered to Desy where they are going to be assembled and tested. To test the module before installing it into the LP we decided to build a small drift chamber, that we will call the Test Box.