Measurement of the ¹⁶O(n, α)¹³C cross-section using a Double Frisch Grid Ionization Chamber

¹ Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Bautzner Landstraße 400, 01328 Dresden, Germany
² Technische Universität Dresden (TUD), 01062 Dresden, Germany
³ European Organization for Nuclear Research (CERN), Route de Meyrin 1211, Genéve, Switzerland
⁴ National Technical University of Athens (NTUA), Zografou Campus 9, Iroon Polytechniou Str, 15780 Zografou, Greece
⁵ Onco Ray - National Center of for Radiation Research in Oncology, Händelallee 26, 01309 Dresden, Germany
⁶ Institute de Physique Nucleaire (IPN), rue Georges Clemenceau, 9406 Orsay, France
⁷ https://www.cern.ch/ntof

^* e-mail: sebastian.urlass@cern.ch

Published online: 30 September 2020

Abstract

The ¹⁶O(n, α)¹³C reaction was proposed to be measured at the neutron time-of-flight (n_TOF) facility of CERN. To this purpose, a Double Frisch Grid Ionization Chamber (DFGIC) containing the oxygen atoms as a component in the counting gas coupled with a switch device in order to prevent the charge collection from the so-called γ-flash has been developed at Helmholtz-Zentrum Dresden-Rossendorf (HZDR), in Germany. The first ¹⁶O(n, α)¹³C measurement without seeing the charge of the γ-flash at n_TOF has been performed in November 2018. After the electronics did not suffer from the y-flash any more, another huge charge collection was discovered. Due to the high instantaneous flux at the n_TOF facility [1] the amount of that induced charge from neutron induced background reactions was piling up so much that the recognition of ¹⁶O(n, α)¹³C reactions from that background was very difficult. For that reason another ¹⁶O(n, α)¹³C measurement at the time-of-flight facility nELBE at HZDR which has a low instantaneous flux [2], has been performed in April 2019. Both measurements from n_TOF and nELBE will be presented here.