大気エアロゾル中の^<32>Pの測定法の検討

概要

論文の詳細を見る
Cosmic ray produced ^<32>P(t_<1/2>=14.3days;E_<max>=1.71MeV) is a powerful tracer of physical and biological processes and the short time scales of atmospheric and upper ocean P cycling. In spite of their tremendous potential for tracing processes involving phosphorus in the environment, the very low activities in nature have impeded their use in biogeochemistry. In order to determine the low-level beta activities of ^<32>P in nature, sample concentration and/or extraction from large volumes of samples are required with a low-level β counting in the field. Preconcentration of the activity in aerosol is achieved here by various concentrating methods. Low-level β counting is achieved by liquid scintillation counting and low background counting. The result of measurement of the activity in aerosol by liquid scintillation counting at Shizuoka University (34°58'N, 138°24'E) ranged from 0.0010±0.0002 to 0.003l±0.0002dpm / m^3 (dpm : disintegrations per minute). Decay-curve in low background counting confirms the existence of ^<33>P(t_<l/2> = 25.3days;E_<max> = 0.25MeV).
静岡大学の論文