Principles of radiation interaction in matter and detection The fourth edition of this book has been widely revised. It includes additional chapters and some sections were complemented with new ones or with an extension of their content. In this edition a complete treatment of the physics and properties of semiconductors is presented. It covers transport phenomena in semiconductors scattering mechanisms radiation effects and displacement damages. Furthermore this edition presents a comprehensive treatment of the Coulomb scattering on screened nuclear potentials resulting from electrons protons light and heavy ions ranging from (very) low up to ultra relativistic kinetic energies and allowing one to derive the corresponding NIEL (non ionizing energy loss) doses deposited in any material. Although a unique book the current edition is in two parts. The first one treats Particle Interactions and Displacement Damage covering the chapters from 1 to 7; the second one on Radiation Environments and Particle Detection extends from the 8th up to the 15th (final) chapter. This book will be of great use to graduate students and final year undergraduates as a reference and supplement for courses in particle astroparticle space physics and instrumentation. A part of the book is directed toward courses in medical physics. The book can also be used by researchers in experimental particle physics at low medium and high energy who are dealing with instrumentation The fourth edition of this book has been widely revised. It includes additional chapters and some sections were complemented with new ones or with an extension of their content. In this edition a complete treatment of the physics and properties of semiconductors is presented. It covers transport phenomena in semiconductors scattering mechanisms radiation effects and displacement damages. Furthermore this edition presents a comprehensive treatment of the Coulomb scattering on screened nuclear potentials resulting from electrons protons light and heavy ions ranging from (very) low up to ultra relativistic kinetic energies and allowing one to derive the corresponding NIEL (non ionizing energy loss) doses deposited in any material. Although a unique book the current edition is in two parts. The first one treats Particle Interactions and Displacement Damage covering the chapters from 1 to 7; the second one on Radiation Environments and Particle Detection extends from the 8th up to the 15th (final) chapter. This book will be of great use to graduate students and final year undergraduates as a reference and supplement for courses in particle astroparticle space physics and instrumentation. A part of the book is directed toward courses in medical physics. The book can also be used by researchers in experimental particle physics at low medium and high energy who are dealing with instrumentation.