Non-Ionizing Energy Loss (NIEL), now used to treat proton-induced displacement effects have been mostly developed within the past decade. This section addresses the justifications, methodology, and associated uncertainties in applying these tools to various classes of Si-based devices as well as emerging III-V technologies for electronic and opto-electronic applications. Emphasis will be given to satellite environments, including shielding efficacy and tradeoffs. Our goal is to capture the current understanding of the many proton-related concerns important to the satellite subsystem engineer. At the beginning of the first section on ionizing effects, a top-level treatment of the environments internal to satellites will be provided, along with references to previous Short Course discussions for additional detail. The emphasis of the remaining material throughout both sections is on the effects, tools, and associated information to enable informed tradeoffs of design options. Section IV. Proton Effects and Test Issues for Satellite Designers Part A: Ionization Effects Paul W. Marshall 7655 Hat Creek Road Brookneal, VA 24528 Cheryl J. Marshall NASA Goddard Space Flight Center Code 562 Greenbelt, MD 20771 1.0 Introduction 2.0 Proton Environments for Satellites 2.1 Environment Description and Issues 2.2 Example Proton Environment Description 2.3 Requirements: Proton Specific Issues 2.3.1 Total Ionizing Dose 2.3.2 Destructive SEE 2.3.3 Nondestructive SEE 2.3.4 Margin 2.3.5 Nonstandard Parts and Waivers 2.4 Recent Updates to the Proton Environment Models 3.0 Total Ionizing Dose and Protons 3.1 Proton-Induced Total Ionizing Dose: Mechanisms and Issues 3.2 Is a rad always a rad? 3.2.1 Lateral Nonuniformities (LNUs) 3.2.2 Electron-Hole Recombination 4.0 Proton-Induced Single Event Effects 4.1 Test Issues and Special Cases 4.1.1 High Speed Technologies 4.1.2 Small Probability Events 4.1.3 Single Event Transients in Linear Devices 4.1.4 Correlation Between Proton and Heavy Ion SEE Sensitivities 4.2 Proton Direct Ionization a