DocumentCode :
3287656
Title :
Convenient method of relative calibration of the neutron source emission rate between different source types
Author :
Harano, H. ; Matsumoto, T. ; Shimoyama, T. ; Sato, Y. ; Uritani, A. ; Hino, Y. ; Kudo, K. ; Michikawa, T.
Author_Institution :
Nat. Metrol. Inst. of Japan, Nat. Inst. of Adv. Ind. Sci. & Technol., Tsukuba
Volume :
1
fYear :
2005
fDate :
23-29 Oct. 2005
Firstpage :
524
Lastpage :
528
Abstract :
Neutron source emission rates are determined by absolute or relative measurement. The relative measurement is performed by comparing between a sample source and a calibrated reference source of the same type. In this calibration, the energy spectra of the sample and reference sources should be identical, since normally there exists energy dependence in the response of neutron detectors. We propose a method of relative calibration of the neutron source emission rate between different source types and spectra. In the present method, a sample source or a calibrated reference source is located at the center of a graphite pile and thermal neutron flux at a special position is monitored and compared. We performed gold foil activation measurements at the NMIJ/AIST graphite pile and revealed that the thermal neutron flux at that position per unit source emission rate is independent on the types of neutron sources. The details of the physical mechanism were examined by calculating the spectral fluence of the neutrons thermalized inside the graphite pile using the MCNP4C code. We demonstrated this method using Am-Be, Ra(alpha)-Be, Cf, Pu-Be neutron sources and obtained the successful results which agreed within 1%
Keywords :
Monte Carlo methods; calibration; neutron detection; neutron flux; neutron sources; neutron spectra; Am-Be neutron source; Cf neutron source; MCNP4C code; NMIJ/AIST graphite pile; Pu-Be neutron source; Ra(alpha)-Be neutron source; calibrated reference source; energy spectra; gold foil activation; neutron detectors; neutron source emission rate; neutron spectral fluence; thermal neutron flux; Calibration; Detectors; Encapsulation; Gold; Impurities; Monitoring; Neutrons; Performance evaluation; Position measurement; Radioactive decay;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Nuclear Science Symposium Conference Record, 2005 IEEE
Conference_Location :
Fajardo
ISSN :
1095-7863
Print_ISBN :
0-7803-9221-3
Type :
conf
DOI :
10.1109/NSSMIC.2005.1596307
Filename :
1596307
Link To Document :
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