Design and Drafting of Prototype Modules for the ATLAS ZDC

The Nuclear Physics Group at the University of Illinois is contributing to upgrade efforts of the ATLAS Zero Degree Calorimeter (ZDC). As part of this effort, two prototype modules along with a single layered reaction plane detector (RPD) are being built for a November beamtest. Improvements have been made to the mechanical design, as well as to the radiation hardness of the detector. Each module consists of 11 alternating layers of tungsten and 12 layers of fused silica fibers. Fused silica with high purity is used to increase the radiation hardness of the detector. In one of the two modules, the tungsten plates are oriented at the Cherenkov angle for better light collection efficiency. In the second module, the plates are oriented vertically. The difference in light yield and timing resolution will be studied for these two configurations. The RPD is also a new addition to the ATLAS ZDC and provides an additional layer of transverse segmentation. Details on the design and construction of these prototype modules will be presented.