Low Power Preamplifier-Dual Discriminator for Proportional Counter Hodoscopes

A proportional counter hodoscope is being developed for measuring particle trajectories in high energy cosmic ray experiments. A significant advantage of proportional counters compared to spark chambers is the inherent ability to measure the trajectory of the heavy primary cosmic rays (2 < Z) in the presence of the copious knock-on electrons and delta rays produced by them. To utilize this advantage, a bi-level discrimination system has been developed based upon a preamplifier-dual discriminator unit which uses the low-level discriminator to sense all particles and the high-level discriminator to sense only heavy particles. The charge sensitive preamplifier-dual discriminatorstorage units which are packaged in hybrid thick film form for the hodoscope consume less than 4 milliwatts of power and weigh only 9 grams.