Rad Hard Active Media For Calorimeters

Zero-degree calorimeters have limited space and extreme levels of radiation. A simple, low cost, radiation hard design uses tungsten metal as the absorber and a suitable liquid as the Čerenkov radiator. In other applications a PPAC (Parallel Plate Avalanche Counter) operating with a suitable atmosphericpressure gas is an attractive active material for a calorimeter. It can be made radiation hard and has sufficient gain in the gas that no electronic components are needed near the detector. It works well even with the highest concentration of shower particles. For this pressure range, R134A (used in auto air conditioners) has many desirable features. Presented at XII International Conference on Calorimetry in High Energy Physics, Chicago, IL, USA, June 5-9, 2006