Counting Efficiency of the Lung Monitor for ²⁴¹Am

Abstract

The counting efficiencies of two lung monitor systems—phoswich detector system and germanium detector system—were measured for lungs and liver loaded with ²⁴¹Am in the JAERI phantom. It was found that the germanium detector system for ²⁴¹Am loaded lungs counting gives the full-energy peak predominated by the absorption of the gamma-ray photon in a single photoelectric interaction and is less sensitive to ²⁴¹Am loaded liver. The ²⁴¹Am loaded lung activities could be reasonably estimated using germanium detector system rather than phoswich detector system.