Evaluation of the spectrum unfolding methodology for neutron activation system of fusion devices

0509964 - ÚJF 2020 RIV CH eng J - Journal Article
Raj, P. - Bradnam, S. C. - Colling, B. - Klix, A. - Majerle, Mitja - Nobs, C. R. - Packer, L. - Pillon, M. - Štefánik, Milan
Evaluation of the spectrum unfolding methodology for neutron activation system of fusion devices.
Fusion Engineering and Design. Roč. 146, č. 9 (2019), s. 1272-1275. ISSN 0920-3796. E-ISSN 1873-7196.
[30th Symposium on Fusion Technology (SOFT). Messina, 16.09.2018-21.09.2018]
R&D Projects: GA MŠMT LM2015056
EU Projects: European Commission(XE) 633053 - EUROfusion
Institutional support: RVO:61389005
Keywords : fusion-diagnostics * neutron-detector * activation-analysis * Gamma-spectroscopy * spectrum-unfolding
OECD category: Nuclear related engineering
Impact factor: 1.692, year: 2019
Method of publishing: Limited access
https://doi.org/10.1016/j.fusengdes.2019.02.056

A neutron activation system (NAS) is a highly useful and reliable tool for neutron flux and energy-spectrum measurements in fusion devices. We are evaluating a fast and efficient methodology for processing of fusion NAS data. Starting with the gamma spectra of irradiated activation materials, the method ultimately produces unfolded spectrum of the incident neutrons and uncertainty estimates. Here, we test the method using data from dedicated experiments at the Joint European Torus (JET) tokamak in Culham and the Nuclear Physics Institute (NPI) in Rez. These measurements utilize few, from three to five reaction channels as input to the unfolding process. Two spectral adjustment code-packages have been adapted for this purpose: MAXED from UMG 3.3 and STAYSL-PNNL. While the former is frequently applied, the latter is a new addition to the case of fusion device NAS. We present the post-analyses of NAS data, spectral adjustments and some discussion on the experiences with these tools, required developments and our planned future studies.
Permanent Link: http://hdl.handle.net/11104/0300545