TWO NEW SINGLE-EXPOSURE, MULTI-DETECTOR NEUTRON SPECTROMETERS FOR RADIATION PROTECTION APPLICATIONS IN WORKPLACE MONITORING

J.M. Gómez-Ros(1,2,*), R. Bedogni(2), D. Bortot(3), C. Domingo(4), A. Esposito(2), M.V. Introini(3), M. Lorenzoli(3), G. Mazzitelli(2), M. Moraleda(1), A. Pola(3) and D. Sacco(2,5)
1 CIEMAT, Av. Complutense 40, 28040 Madrid, Spain
2 IFNF—LNF Laboratori Nazionali di Frascati, via E. Fermi n. 40, 00044 Frascati, Italy
3 Politecnico di Milano—Dipartimento di Energia, Via Ponzio 34/3, 20133 Milano, Italy
4 UAB, Physics Department, 08193 Bellaterra, Spain
5 INAIL-DIT, Via di Fontana Candida 1, 00040 Monteporzio Catone, Italy

*Corresponding author: jm.gomezros@ciemat.es
Accepted 28 October 2016

This communication describes two new instruments, based on multiple active thermal neutron detectors arranged within a sin- gle moderator, that permit to unfold the neutron spectrum (from thermal to hundreds of MeV) and to determine the corre- sponding integral quantities with only one exposure. This makes them especially advantageous for neutron field characterisation and workplace monitoring in neutron-producing facilities. One of the devices has spherical geometry and nearly isotropic response, the other one has cylindrical symmetry and it is only sensitive to neutrons incident along the cylin- der axis. In both cases, active detectors have been specifically developed looking for the criteria of miniaturisation, high sensi- tivity, linear response and good photon rejection. The calculated response matrix has been validated by experimental irradiations in neutron reference fields with a global uncertainty of 3%. The measurements performed in realistic neutron fields permitted to determine the neutron spectra and the integral quantities, in particular H*(10). Full PDF