title: Correction and verification of AECL Bonner Sphere response matrix based on mono-energetic neutron calibration performed at NPL.
abstract: The AECL Bonner Sphere Spectrometer (BSS) was taken to National Physical Laboratory (NPL) for calibration in mono-energetic neutron fields and bare (252)Cf neutron fields. The mono-energetic radiations were performed using ISO-8529 prescribed neutron energies: 0.071, 0.144, 0.565, 1.2, 5 and 17 MeV. A central SP9 proportional counter was also evaluated at the NPL thermal neutron calibration facility in order to assess an effective pressure of (3)He inside the counter, i.e. number density of (3)He atoms. Based on these measurements and methods outlined by Thomas and Soochak, a new BSS response matrix was generated. The response matrix is then verified by unfolding spectra corresponding to various neutron fields. Those are NPL bare (252)Cf source, National Institute of Standards and Technology bare and heavy water moderated (252)Cf source and (241)AmBe calibration source located at National Research Council. A good agreement was observed with expected neutron fluence rates, as well as derived dosimetric quantities, such as International Commission on Radiological Protection-74 ambient dose equivalent.
authors: Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, ONT, Canada K0J 1J0 atanackj@aecl.ca.
authors: J
authors: J
authors: Atanackovic
authors: National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW, UK.
authors: D J
authors: DJ
authors: Thomas
authors: National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW, UK.
authors: N J
authors: NJ
authors: Roberts
authors: DETEC, Gatineau, QC, Canada J8 T 4J1.
authors: S
authors: S
authors: Witharana
authors: DETEC, Gatineau, QC, Canada J8 T 4J1.
authors: J
authors: J
authors: Dubeau
authors: Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, ONT, Canada K0J 1J0.
authors: A
authors: A
authors: Yonkeu
mesh_terms: D000465:Algorithms; D000576:Americium; D001608:Beryllium; D002138:Calibration; D002142:Californium; D002170:Canada; D004867:Equipment Design; D006371:Helium; D009010:Monte Carlo Method; D009502:Neutrons; D020959:Polyethylene / Q000737:chemistry; D011381:Programming Languages; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods*; D015203:Reproducibility of Results; D012984:Software
chemical_list: D006371:Helium; D020959:Polyethylene; D002142:Californium; D001608:Beryllium; D000576:Americium