Unfolding Of Neutron Spectra With An Experimentally Determined Diamond Detector Response Function
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2016-10-26 |
| Authors | A. Zimbal, F. Gagnon-Moisan, Marcel Reginatto, M. ZboÅil |
| Institutions | Paul Scherrer Institute, Physikalisch-Technische Bundesanstalt |
Abstract
Section titled āAbstractāRadiation detectors made from artificial chemical vapor deposition (CVD) single crystal diamond have shown great potential for neutron spectrometry. The detectors are small, typically about (5 Ć 5 Ć 0.5) mm3, they are not very sensitive to gamma radiation, and they have good radiation hardness properties. They are, therefore, very promising candidates for applications where high resolution neutron spectrometry in very high neutron fluxes is required, such as in fusion research.<br />A measurement with a single crystal CVD diamond detector results in a pulse height spectrum which contains information about the energy spectrum of the incident neutrons. Unfolding methods can be used to extract this information, but this requires a response matrix. Current particle transport codes, while able to provide important information, are of limited use because they cannot simulate neutron responses of CVD diamond detectors that are of high enough quality to be used for unfolding. Consequently, we have determined the neutron response matrix from measurements.<br />The response matrix covers the energy range 10.0 MeV < En < 16.0 MeV. It is based on six measurements of monoenergetic neutron beams produced at the Physikalisch-Technische Bundesanstalt (PTB) ion accelerator facility (PIAF). A Bayesian approach that incorporates signal-background separation techniques and thin plate spline radial basis function interpolation was used to get the full response matrix from this rather limited amount of data. To test the quality of the response matrix, we have done unfoldings of additional measurements with monoenergetic neutron spectra. These were also made at PIAF. The unfolded spectra are in good agreement with numerical simulations of these spectra.