a. Radiation shielding calculations shall be performed to determine the radiation environment at the instrument after passing through the spacecraft structure.
b. Background effects in instruments shall be analysed using:
1. calculations or simulations of the energy-deposition processes in sensitive volumes, or
2. results from particle accelerator irradiations of the instrument or its sensitive components, or
3. a combination of both of the requirements 10.4.1b.1 and 10.4.1b.2.
c. Where experimental results from component tests are used, or simulations based on components of the instrument, one of the following shall be performed:
1. shielding calculations for the instrument, to determine the incident particle spectrum on the sensitive volume(s) of the instrument, or
2. an analysis demonstrating that instrument structure has a negligible perturbing effect on the radiation field.
d. Where grazing-incidence mirrors are used, the calculation of the radiation environment at the sensitive volumes of the instrument shall include the effects of Firsov scattering and shallow angle multiple scattering of protons in the grazing-incidence mirrors.
NOTE See ECSS-E-HB-10-12 Section 9.4, for the reasons for including Firsov scattering in the simulation.