MEASURING RADIO-ACTIVE EMISSIONS FROM MATERIAL

摘要

A method of and apparatus for measuring radio-active emissions from moving radio-active material. Use is made of a radiation detector, a first radiation shield of a first material which shields the detector, and a second radiation shield which is located between at least a portion of the first shield and the detector. The material of the second shield is inherently less contaminated and emits secondary excitation radiation of lower energy than the first material.