A Low Cost-Low Power Multichannel Pulse Height Analyzer for University Balloon and Rocket Experiments

A simple low cost-low power consumption multichannel pulse height analyzer has been designed and fabricated for balloon and rocket use. This analyzer was designed to be used in a balloon experiment with a directional neutron detector to search for solar neutrons with energies greater than 10 Mev. It can-operate in the temperature range of -30°C to +70°C and can withstand storage temperature from -50°C to +90°C. The input pulses are digitized by an analog to digital converter with a clock rate of 2 MC. The output of the PHTC is read out by a series binary converter and is transmitted by a single subcarrier channel (70 KC ± 15% deviation standard IRIG Band E) to the ground, where it can be stored on tape or directly stored in a laboratory pulse height analyzer memory unit. The dead time of the PHTC is approximately 64 ¿sec, but the bandwidth of the subcarrier limits the overall dead time to 600 ¿sec. The analyzer was designed as a 32-channel pulse height analyzer, but by adding a stage to the series binary converter it can be used as a 64, or 128-channel pulse height analyzer. The total average power consumption is approximately 330 mW. The analysis range is from 150 mV to 4.6 V with adjustable zero setting. An external anticoincidence input is provided. This work was supported by the National Aeronautics and Space Administration under Contract NASr-211.