Radiation Protection Instrumentation

This article describes common radiation protection instruments used around or with radioactive materials and equipment in medical facilities. This article describes availability of instruments and sources of information about their use; instruments for specific tasks; types and sources of radiation; international definitions of radiation quantities and units; and common features of instruments. The detection principles of ionization chambers, gas proportional counters, Geiger–Mueller detectors, scintillation detectors (solid, liquid, and plastic), solid-state detectors (semiconductors, thermally, and optically stimulated luminescence phosphors), and photographic detectors are described. Worldwide web Internet addresses are given for some major instrument manufacturers and vendors. The bibliography lists the latest editions of relevant textbooks. Common medical uses of these instruments include equipment surveys; personnel and area monitoring; contamination surveys; locating misplaced radioactive sources; air sampling; responding to emergencies; and spectroscopy. Using recent data (2002) from the Committee on Data for Science and Technology, this article describes electrons, beta particles, alpha particles, protons, neutrons, X rays, γ rays, and some radionuclides commonly used in medicine. Fundamental terms (exposure, kerma, absorbed dose), internationally recommended definitions of terms used for radiation protection (equivalent dose, committed equivalent dose, effective dose, committed effective dose), and units (roentgen, gray, sievert) are described. Currently used personnel radiation monitors are described. Instrument electronic circuitry is discussed only briefly. Keywords: radiation; protection; instrumentation; health physics