This book describes the development of sources of negative ions and their application in science and industry. It describes the physical foundations and implementation of the key methods of negative ion production and control, such as charge exchange, thermionic emission, secondary emission (sputtering) and surface-plasma sources, as well as the history of their development. Following on from this essential foundational material, the book goes on to explore transport of negative ion beams, and beam-plasma instabilities. With exposition accessible at the graduate level, and a comprehensive bibliography, this book will appeal to all students and researchers whose work concerns ion sources and their applications to accelerators, beam physics, storage rings, cyclotrons, and plasma traps.