Development of a Digital Amplifier for Nuclear Radiation Detectors

Abstract

Many types of radiation sensors, including solid-state diodes, ion chambers, fission chambers, and self-powered detectors, give a signal consisting of a current or charge proportional to the incident radiation. The output signal is traditionally amplified by a current-to-voltage amplifier, and processed downstream by various analogue signal conversion and processing steps before digitization for display or for use in a control, safety, or monitoring system. The present work describes the development of a “digital amplifier” system, capable of directly digitizing the small current or charge output signal from radiation sensors, so that all downstream signal processing, display, and decision-making can be accomplished digitally. The size, simplicity, accuracy, robustness, and self-checking capability of the digital amplifier make it suitable for use in modern nuclear power plant instrumentation and control systems.