Relating SGEMP photon test exposures to spacecraft survivability expectations

An interpolation method for defining the rules for construction of a simulator to examine the threats posed to spacecraft electronics by the presence of both system generated EMP (SGEMP) and transient radiation effects in electronics (TREE) is described. The methodology comprises identification of every location where photon interaction produces electrons to drive the SGEMP and quantification of stress parameters and their relation to photon pulse parameters. The fluence required by a simulator to reproduce the threats is then defined in terms of the largest expected exposure and the smallest equivalent fluence. Determination of the possibility that changes of spacecraft design could lessen the fluence is recommended, as are devising different scenarios which could change the fluence levels. Examples are provided of analyses of threat characteristics from plasma and bremsstrahlung sources, with attention given to satellite thermal blankets.