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$^{16}$O(n,$\alpha_0$)$^{13}$C Cross Section Normalization based on a new Time-of-Flight measurement using a Frisch Grid Ionisation Chamber.

11 Nov 2021, 14:25
25m
Virtual

Virtual

Speaker

Sebastian Urlass (Helmholtz-Zentrum Dresden-Rossendorf)

Description

A $^{16}$O(n,$\alpha$)$^{13}$C reaction cross section measurement was carried out at the time-of-flight facility GELINA using a Frisch-grid ionization chamber built by HZDR. Between the reaction threshold (2.36 MeV) and a neutron energy of 9 MeV, $^{16}$O(n,$\alpha_0$)$^{13}$C events could be separated well from background events.
The experimental $^{16}$O(n,$\alpha_0$)$^{13}$C data are normalized relative to the neutron-induced fission cross section of $^{235}$U of the neutron data standards using the H19 transfer instrument of PTB Braunschweig.
Applying the principle of detailed balance, cross sections measured for the $^{13}$C($\alpha$,n$_0$)$^{16}$O reaction (from Bair and Haas, Sekharan and Harissopulos)
above E$_\alpha$=1 MeV, are converted to $^{16}$O(n,$\alpha_0$)$^{13}$C cross section data and has been normalized to the cross-section integral over of the measured data from 4.0 to 5.3 MeV.
Evaluated $^{16}$O(n,$\alpha$)$^{13}$C data could be normalized as well.
An alternative normalization for the evaluated cross sections and $^{13}$C($\alpha$,n)$^{16}$O data which is based on the $^{13}$C($\alpha$,n$_0$)$^{16}$O thick target yield data of West and Sherwood is also presented and has an uncertainty of 8%. The data by West and Sherwood, used for this normalization are supported by two additional mutually consistent independent thick-target yield measurements.
The two sets of normalization factors agree within 3%.

Primary authors

Sebastian Urlass (Helmholtz-Zentrum Dresden-Rossendorf) Arjan Plompen (European Commission Joint Research Centre, Geel) Arnd Junghans (Helmholtz-Zentrum Dresden-Rossendorf)

Co-authors

Roland Beyer (Helmholtz-Zentrum Dresden-Rossendorf) Toni Kögler (Helmholtz-Zentrum Dresden-Rossendorf) Peter Schillebeeckx (European Commission Joint Research Centre, Geel) Stefan Kopecky (European Commission Joint Research Centre, Geel) Jan Heyse (European Commission Joint Research Centre, Geel) Laurent Tassan-Got (European Organization for Nuclear Research) Luiz Leal (Institut de Radioprotection et de Sûreté Nucléaire) Alf Göök (European Commission Joint Research Centre, Geel) Markus Nyman (European Commission Joint Research Centre, Geel) Carlos Paradela (European Commission Joint Research Centre, Geel)

Presentation materials