Model-data comparison of total dose experiment on KITSAT-1

Using a model developed for temperature-dependent irradiations, we analyze the results of the KITSAT-1 total dose experiment (TDE) accumulated during more than two years from September 1992 through December 1994. Monte Carlo simulations are adopted for the calculation of effective shielding thickness of the spacecraft at the position of TDE. With parameters obtained from a laboratory Co⁸⁰ γ-ray experiment, the model reproduces the observed threshold voltage changes quite successfully, including peculiar oscillations caused by temperature variations. The total dose received by TDE is estimated to be about 40% larger than the NASA predictions, in general agreement with the APEXRAD model.