Neutron calibration field at Institute for Nuclear Science and Technology
Main Article Content
Abstract
In this study, a neutron calibration field of a 241Am-Be standard source at the Institute for Nuclear Science and Technology is characterized in terms of neutron spectral fluxes and neutron ambient dose equivalent ( ) rates based on ISO 8529 recommended generalized fit method together with measurements using a Bonner Sphere Spectrometer and MAXED unfolding techniques. The total, direct and scattered neutron components as well as rates and neutron spectral fluxes are separated from each other. The direct rates and neutron spectral fluxes in the free field as functions of distances from the source are also theoretically calculated based on the neutron source strength. The comparison between experimental data and theoretical calculations of the rates and neutron spectral fluxes shows good agreement within 3%, this has confirmed the reliability of the field characterization process and its applicability in the practical calibration works for neutron survey meters.
Article Details
Keywords
neutron calibration field, neutron spectral fluxes, nDE rates, generalized-fit method
References
[2]. ISO 8529-2:2001 (E); Reference Neutron Radiations - Part 2: Calibration Fundamentals of Radiation Protection Devices Related to the Basic Quantities Characterizing the Radiation Field; Switzerland; p.38, 2000.
[3]. M. Reginatto and P. Goldhagen; MAXED, A Computer Code for the Deconvolution of Multisphere Neutron Spectrometer Data Using the Maximum Entropy Method. Environmental Measurements Laboratory; US-DOE Report EML 595, p. 40, 1998.
[4]. M. Reginatto; The "few-channel" unfolding programs in the UMG package: MXD_FC33, GRV_FC33 and IQU_FC33; Physikalisch-Technische Bundesanstalt (PTB), version 3.3, p. 51, 2004.
[5]. IAEA Technical Reports Series No. 403; Compendium of Neutron Spectra and Detector Responses for Radiation Protection Purposes - Supplement to Technical Reports Series No.318; p.276, 2001.
[6]. http://www.originlab.com/doc/Origin-Help/FIt-with-Err-Weight. (accessed on Dec.05-2016)
[7]. S.I. Kim, B.H. Kim, J.L. Kim, J.I. Lee.; Review of Neutron Scattering Correction for the Calibration of Neutron Survey Meters using the Shadow-cone Method; Nuclear Engineering and Technology 47, pp.939-944, 2015.
[8]. ICRP Publication 74: "Conversion Coefficients for Use in Radiological Protection against External Radiation", Annals of the ICRP, 26, 3-4, 1996.
[9]. ISO 8529-1:2001 (E): Reference Neutron Radiations – Part 1: Characteristics and Methods of Production. p.32, 2001, Switzerland.