10.4.2           Prediction of effects from direct ionisation by charged particles

a.              The energy deposition spectrum by direct ionisation shall be calculated by one of the following methods:

1.              By using the formula of Clause 10.4.9.1, if both of the following conditions are met:

(a)            the sensitive volume of the sensor is so small that the incident particle spectrum changes by less than 10%  in either intensity or energy after passing through the volume;

(b)           the pathlength distribution changes by less than 10% as a result of multiple scattering.

2.              By a radiation transport simulation agreed with the customer.

NOTE              For guidelines, see ECSS-E-HB-10-12 Section 5.7.

b.              If method specified in requirement 10.4.2a.1 is used, the following shall be performed:

1.              An estimation of the combined effects of the maximum change in energy, intensity and pathlength on the energy deposition, and

2.              A demonstration that the error produced is within the accepted margins defined for the project.