In-beam test of the Boron-10 Multi-Grid neutron detector at the IN6 time-of-flight spectrometer at the ILL

International Workshop on Neutron Optics and Detectors

Birch, J.^1 ; Buffet, J.-C.^2 ; Clergeau, J.-F.^2 ; Correa, J.^2 ; Van Esch, P.^2 ; Ferraton, M.^2 ; Guerard, B.^2 ; Halbwachs, J.^2 ; Hall-Wilton, R.^3 ; Hultman, L.^1 ; Höglund, C.^1,3 ; Khaplanov, A.^2,3 ; Koza, M.^2 ; Piscitelli, F.^2 ; Zbiri, M.^2

Linköping University, Thin Film Physics Division, IFM, SE-581 83 Linköping, Sweden^1

Institute Laue Langevin, Rue Jules Horowitz, FR-38000 Grenoble, France^2

European Spallation Source ESS AB, P.O Box 176, SE-221 00 Lund, Sweden^3

关键词: Aluminum substrate;    Detector concepts;    Efficiency comparisons;    Neutron scattering instruments;    Position sensitive;    Time of flight spectrum;    Time-of-flight choppers;    Time-of-flight spectrometer;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/528/1/012040/pdf
DOI  :  10.1088/1742-6596/528/1/012040

来源: IOP

【 摘 要 】

A neutron detector concept based on solid layers of boron carbide enriched in10B has been in development for the last few years as an alternative for3He by collaboration between the ILL, ESS and Linkoping University. This Multi-Grid detector uses layers of aluminum substrates coated with10B4C on both sides that are traversed by the incoming neutrons. Detection is achieved using a gas counter readout principle. By segmenting the substrate and using multiple anode wires, the detector is made inherently position sensitive. This development is aimed primarily at neutron scattering instruments with large detector areas, such as time-of-flight chopper spectrometers. The most recent prototype has been built to be interchangeable with the3He detectors of IN6 at ILL. The10B detector has an active area of 32 x 48cm2. It was installed at the IN6 instrument and operated for several weeks, collecting data in parallel with the regularly scheduled experiments, thus providing the first side-by-side comparison with the conventional3He detectors. Results include an efficiency comparison, assessment of the in-detector scattering contribution, sensitivity to gamma-rays and the signal-to-noise ratio in time-of-flight spectra. The good expected performance has been confirmed with the exception of an unexpected background count rate. This has been identified as natural alpha activity in aluminum. New convertor substrates are under study to eliminate this source of background.