Comparison of Radiation Transport Codes for Solar Particle Events Space Environment

摘要

For long duration and/or deep space human missions, protection from severe space radiation exposure is a challenging design constraint and may be a potential limiting factor. The space radiation environment consists of galactic cosmic rays (GCR), solar particle events (SPE), trapped radiation, and includes ions of all the known elements over a very broad energy range. These ions penetrate spacecraft materials producing nuclear fragments and secondary particles that damage biological tissues, microelectronic devices, and materials. Accurate risk assessments critically depend on the accuracy of the input information as well as radiation transport codes used, and so systematic verification of codes is necessary. Since solar particle events are of concern for long duration, deep space missions to moon or Mars, historical SPE spectra can be used to benchmark these codes. In this study, comparisons are made between the deterministic code HZETRN2006 and the Monte Carlo codes HETC-HEDS and FLUKA for an aluminum shield and water target exposed to the February, 1956 Webber SPE spectrum. Dose, dose equivalent and fluence spectra are compared; and conclusions are drawn for future directions.