Precision measurement in Gamma-ray spectroscopy

Gamma-ray spectrometers suitable for precision measurements, i.e. those capable of an energy resolution exceeding 1 per cent and an energy accuracy better than 0·2 per cent, are discussed according to the γ-ray interaction used: coherent scattering (crystal diffraction), photoelectric effect, Compton effect, and pair production. Leading instruments of each type are described and the energy range, resolution, efficiency function, and precision in energy and intensity measurement are discussed and, in some cases, ways of improving existing instruments are indicated. The suitability of the various instruments for different applications is considered and, where more than one type of instrument can be used under identical conditions, attempts are made to compare their relative merits.