SIS SS-ISO 8529:1990 Neutron reference radiations for calibrating neutron-measuring devices used for radia- tion protection purposes and for determining their response as a function of neutron energy
This International Standard specifies the neutron reference radiations, in the energy range from thermal up to 20 MeV, for calibrating neutron-measuring devices used for radiation pro-tection purposes and for determining their variation in response as a function of neutron energy. Reference radiations are given for neutron fluence r?tes of up to 105 cm-2-s-1, correspon-ding, at a neutron energy of 1 MeV, to dose equivalent r?tes of up to 100 mSv-h"1 (10 rem-h"'). This International Standard applies to radiation protection calibrations in units of the quan-tity "dose equivalent", but values are also given in units of the quantities "absorbed dose" and "kerma" in "standard man tissue".
It should be noted that at the present time, the definitions of "dose equivalent" quantities to be used for radiation protection purposes are under review by both the ICRU and the ICRP1'. The definitions of "dose equivalent" and the conversion factors from neutron fluence to dose equivalent given in this International Standard are therefore subject to possible revision.
This International Standard is concerned only with the methods of producing the neutron reference radiations. The procedures for applying these radiations will be described in a future International Standard.
The reference radiations specified are the following:
— neutrons from radionuclide sources, including neutrons from sources in a moderator;
— neutrons produced by nuclear reactions with charged particles from accelerators;
— neutrons from reactors.
In view of the methods of production and use of them, these reference radiations are divided, for the purposes of this International Standard, into two separate clauses:
— In clause 4, radionuclide neutron sources with wide spectra are specified for the calibration of neutron-measuring devices. These sources shall be used by laboratories engaged in the routine calibration of neutron-measuring devices, the particular design of which has already been type tested.
— In clause 5, accelerator-produced monoenergetic neutrons, reactor-produced neutrons with wide and quasi-monoenergetic spectra, and special radionuclide sources are specified for determining the response of neutron-measuring devices as a function of neutron energy. Since these reference radiations are produced at specialized and well equipped laboratories, only the minimum of experimen-tal detail is given.
For the conversion of "neutron fluence" into the quantities recommended for radiation protection and related purposes, the following conversion factors are specified:
— "neutron fluence" to "dose equivalent";
— "neutron fluence" to "charged particle absorbed dose";
— "neutron fluence" to "photon absorbed dose";
— "neutron fluence" to "kerma".
The conversion factors given in annexes B and C are based on the spectra presented in annex A, and on the "fluence" to "dose" conversion factors referred to in 3.6, 3.8 and 3.11. This International Standard does not preclude the use of the reference radiations specified in this International Standard with other "fluence" to "dose" conversion factors, if ap-plicable, in particular those obtained for a different phantom and/or dose equivalents defined at different positions in the phantom. At the present time, the "fluence" to "dose" conversion factors presented in this International Standard are the only internationally accepted values.
SIS SS-ISO 8529:1990 history
1990SIS SS-ISO 8529:1990 Neutron reference radiations for calibrating neutron-measuring devices used for radia- tion protection purposes and for determining their response as a function of neutron energy