s for predicting proton induced device degradation in a space environment based on both the calculated NIEL and relatively few laboratory test measurements. The methodology of such on-orbit device performance predictions will be described, as well as the limitations. Several classes of devices for which displacement damage is a significant (if not the dominant) mode of radiation induced degradation will be presented. The examples IV-51 will illustrate various aspects of displacement damage in more detail. We will see, over and over, that the impact of a particular level of damage on device performance is very application-dependent. It will also become clear that uncertainties in the on-orbit prediction for devices sensitive to displacement damage may require significantly increased radiation design margins. All too often, the design engineer is more familiar with basic total ionizing dose (TID) and traditional SEE effects, and may find it difficult to accept the need for proton testing, and especially, any increased radiation design margin associated with uncertainties in displacement damage analyses. There is an increasing demand to employ displacement damage sensitive devices (e.g., charge coupled devices (CCDs), photodetectors, light emitting diodes (LEDs), optocouplers, solar cells, and high precision linear devices) in harsh proton environments (and/or on longer missions). This has led to a renewed interest in hardness assurance techniques for such devices [LaBe98]. It is hoped that this course will provide the understanding necessary for a radiation effects engineer to identify technologies requiring evaluation for possible displacement effects, use the current literature to make first order estimates of device performance, and help ensure that appropriate laboratory radiation testing and analyses are performed. For those readers interested in surveying proton induced device effects (as opposed to performing displacement damage analyses), we recommend reading section 2.2 on displacement effects in devices f