title: Validating a MCNPX model of Mg(Ar) and TE(TE) ionisation chambers exposed to 60CO gamma rays.
abstract: For an accurate determination of the absorbed doses in complex radiation fields (e.g. mixed neutron-gamma fields), a better interpretation of the response of ionisation chambers is required. This study investigates a model of the ionisation chambers using a different approach, analysing the collected charge per minute as a response of the detector instead of the dose. The MCNPX Monte Carlo code is used. In this paper, the model is validated using a well-known irradiation field only: a (60)Co source. The detailed MCNPX models of a Mg(Ar) and TE(TE) ionisation chamber is investigated comparing the measured charge per minute obtained free-in-air and in a water phantom with the simulated results. The difference between the calculations and the measurements for the TE(TE) chamber is within +/-2% whereas for the Mg(Ar) chamber is around +7%. The systematic discrepancy in the case of Mg(Ar) chamber is expected to be caused by an overestimation of the sensitive volume.
authors: High Flux Reactor, Institute for Energy, Joint Research Centre, European Commission, Petten, The Netherlands. antoaneta.roca@jrc.nl
authors: A
authors: A
authors: Roca
authors: V A
authors: VA
authors: Nievaart
authors: R L
authors: RL
authors: Moss
authors: F
authors: F
authors: Stecher-Rasmussen
authors: N V
authors: NV
authors: Zamfir
mesh_terms: D001128:Argon / Q000737:chemistry*; D003037:Cobalt Radioisotopes; D005720:Gamma Rays; D008274:Magnesium / Q000737:chemistry*; D009010:Monte Carlo Method; D009502:Neutrons; D011874:Radiometry / Q000295:instrumentation*; D013691:Tellurium / Q000737:chemistry*
chemical_list: D003037:Cobalt Radioisotopes; D001128:Argon; D008274:Magnesium; D013691:Tellurium