Book excerpt: Nineteen experts from the electronics industry, research institutes and universities have joined forces to prepare this book. It does nothing less than provide a complete overview of the electrophysical fundamentals, the present state of the art and applications, as well as the future prospects of microwave tubes and systems. The book does the same for optoelectronics vacuum devices, electron and ion beam devices, light and X-ray emitters, particle accelerators and vacuum interrupters.