Novel 4π Detection System for the Measurement of the 6Li(n,α)3H Reaction Cross-Section

A dedicated one-dimensional Time Projection Chamber (1D-TPC) was designed and produced at IRMM to determine the 6Li(n,α)3H cross section, in the 0.4-2.8 MeV energy range, aiming at 5% accuracy. The basic TPC components were a twin gridded ionisation chamber (GIC) with interwired electrodes and fast digitisation of the anode and cathode signals. The energy of both reaction products emitted from a thin 6LiF sample at the common TPC cathode was measured. A Kr(97%)CO2(3%) mixture was used as the detector gas at a pressure up to 3.5 bar. A 238U sample mounted on the cathode of an ionisation chamber without grid was used as the neutron flux monitor. Special care was taken to reduce the experimental sources of uncertainty. The beam-monitor 238U sample was characterised at IRMM by low-geometry α-counting with an accuracy of 0.1%. A 6Li sample was produced at IRMM by vacuum evaporation of 6LiF onto transparent aluminium backing. The number of 6Li atoms will be measured via Thermal Neutron Depth Profiling with an expected accuracy of 2% with respect to an IRMM Standard Reference Material. First test measurements were performed using a monoenergetic neutron beam produced by the T(p,n)3He reaction at the IRMM 7MV Van de Graaff accelerator. The experimental method and preliminary results are presented.

GIORGINIS Georgios;  BENCARDINO Raffaele; 

2012-12-31

AMERICAN INSTITUTE OF PHYSICS

JRC66004

0094-243X,   

http://dx.doi.org/10.1063/1.3665311,    https://publications.jrc.ec.europa.eu/repository/handle/JRC66004,   

10.1063/1.3665311,