Calculation of Irradiation of Device Incident Proton with Monoenergetic Spectrum for Protons Given Mission Calculation of Measurement of Parametric Spectrum at Device Location Behind Degradation Shielding Calculation of Calculation of Device Degradation DD Dose* for versus Given Mission DD Dose* Prediction of On-Orbit Device Performance * DD Dose is displacement damage dose. Alternatively one may substitute the displacement damage equivalent fluence for a selected proton energy. Figure 1 Block diagram of the generic methodology for performing a on-orbit predictions of device performance when device degradation is dominated by displacement damage effects. 2.1 Displacement Damage Mechanisms and Defect Formation As indicated above, the interaction between a charged particle (such as a proton) and a solid cause both ionizing and non-ionizing effects. Most of the kinetic energy of an incident proton is lost in interactions with atoms in the semiconductor that transfer energy to the electron clouds causing excitation or ionization. However, a very small fraction (< 0.1%) of the energy loss causes the atoms to be displaced from their equilibrium sites, and can lead to lattice disorder. An incident proton may collide with a semiconductor nucleus and displace it from its site producing a primary knock-on atom (PKA). sufficiently energetic, the PKA displaces more atoms, and the collision cascade proceeds until the magnitude of energy transferred becomes less than the threshold required for displacements. At a given incident proton energy, the recoil atoms can vary in kinetic energy from near zero up to some maximum determined by collision mechanisms. Both IV-53 the average recoil energy and the shape of the recoil spectrum depend on the energy, mass, and charge of the incident particle and the mass of the target. EXITING PARTICLE STABLE DEFECT INCIDENT PARTICLE Interstitial Vacancy Dopant of Impurity Atom Figure 2a Cartoon showing the displacement of an atom from its lattice site by an incoming proton, thereby forming a va