An analysis of energy deposition in a tissue equivalent proportional counter onboard the space shuttle

Abstract

An improved prediction for space radiations in the lower earth orbits measured by the shuttle TEPC is obtained when energy loss straggling and chord length distribution of the detector are considered. A generalized analytic model is used to describe the energy deposition of direct ion interaction events in a micron-size detector. The transport calculation accounting for the shuttle configuration is accomplished by using a new version of HZETRN that has been extensively verified with laboratory and flight data. The agreement of predicted and measured lineal energy spectra is within 70% for the region above 2 keV/ μm but within a factor of 2.3 underpredicted for the region below this value. The inclusion of indirect delta ray events in the model is needed before possible causes for the underprediction below 2 keV/ μm can be assessed.