Determination of Intake Radioactivity by γ(HPGe)-γ(HPGe) Coincidence Measurement

Abstract

It is important to estimate internal exposure dose from intake radioactivity measured by human counter. The previous paper described application of the γ-γ coincidence method to human counter using two large HPGe detectors and showed equation to calculate activity without determination of γ-ray detection efficiency. This paper showed the results of further experiments using absorbers based on the previous fundamental experiments. When absorption of γ-rays in human body was simulated by depth of water on the source, the activities obtained for various depth agreed with true activity within ±10%. Furthermore, a moving source like a human in X-ray CT apparatus was measured to simulate whole body counting and the result showed usefulness of this method for human counter.