Development of Ion Current Prediction Model in Alpha Radioactivity Measurement using Ionized Air Transportation

• Published in: Nihon Genshiryoku Gakkai wabun ronbunshi = Transactions of the Atomic Energy Society of Japan Vol. 4; no. 1; pp. 7 - 15
• Main Authors: Naito, Susumu, Sano, Akira, Izumi, Mikio, Kanemoto, Shigeru, Miyamoto, Yasuaki, Fukumoto, Masahiko
• Format: Journal Article
• Language: Japanese
• Published: 01.01.2005
• ISSN: 1347-2879
• DOI: 10.3327/taesj2002.4.7

A theoretical model for Alpha radioactivity Measurement using ionized Air Transportation (AMAT) is developed to predict the relation between alpha radioactivity and measured ion current. AMAT is very efficient for measuring alpha contaminated wastes with large and complex surfaces. However, since the theoretical relation between alpha radioactivity and observed ion current is unclear because of the complicated behavior of ionized air molecules, one-dimensional model covering from ionization of air molecules to ion detection is developed based on atmospheric electrodynamics. The model prediction of ion current was quantitatively in agreement with the experimentally observed ion current in the simple AMAT system, within 40% errors of absolute ion current values. Also, the model can qualitatively predict the dependency of measured ion current on the air velocity.