Authors:Y. Hatsukawa, N. Shinohara, K. Hata, K. Kobayashi, S. Motoishi, M. Tanase, T. Katoh, S. Nakamura, and H. Harada
To determine the cross sections of the135Cs(n,γ)136Cs reaction, a sample of135Cs included in a “standardized solution” of137Cs was used as a target and irradiated in a reactor. The ratio of the atom number of135Cs to that of137Cs was determined to be 0.89±0.03 with a quadrupole mass spectrometer. The thermal cross section and the resonance integral
measured in this study were determined to be 8.3±0.3 and 38.1±2.6 b respectively.
Authors:Y. Oura, R. Watanabe, M. Ebihara, Y. Murakami, Y. Toh, A. Kimura, M. Koizumi, K. Furutaka, M. Oshima, K. Hara, T. Kin, S. Nakamura, and H. Harada
A prompt gamma-ray analysis system using multiple detection method (MPGA system) was constructed at the neutron guide hall
of the JRR-3M reactor of the Japan Atomic Energy Agency. We applied MPGA method to geochemical and cosmochemical samples to
evaluate its analytical performance on signal to noise (S/N) ratio, sensitivity, and detection limit. The S/N ratio measured
by MPGA system was larger than that by normal prompt gamma ray activation analysis (PGAA) at JRR-3M. For some elements, the
S/N ratio was improved more than ten times. Several elements that are not detected by PGAA were detected by MPGA. At the present
time, concentrations of major elements and trace elements with high neutron capture cross section in geochemical and cosmochemical
samples were determined accurately by the MPGA system installed at JRR-3M. It is expected that it will determine a lot of
trace elements after appropriate adjustments and modifications.