Prompt γ radiation measured with a Nal scintillation detector: a beam monitor for neutron scattering instruments which needs no space in the beam

International Workshop on Neutron Optics and Detectors

Holderer, O.^1 ; Zamponi, M.^1 ; Monkenbusch, M.^2 ; Engels, R.^3

Jülich Centre for Neutron Science (JCNS), Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Julich, Lichtenbergstr. 1, 85747 Garching, Germany^1

Jülich Centre for Neutron Science (JCNS), Institute for Complex Systems, Forschungszentrum Jülich, D-52425 Jülich, Germany^2

Zentralinstitut für Engineering, Elektronik und Analytik, Systeme der Elektronik (ZEA-2), Forschungszentrum Jülich, D-52425 Jülich, Germany^3

关键词: Beam chopper;    Beam monitor;    Neutron scattering instruments;    Prompt gamma-rays;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/528/1/012038/pdf
DOI  :  10.1088/1742-6596/528/1/012038

来源: IOP

【 摘 要 】

We investigate the possibility of using the prompt γ rays emitted by aluminum windows in order to monitor the neutron flux of the beam. A Nal scintillation detector is used to detect the prompt γ rays. No additional material apart from the unavoidable Al windows along the flight path is placed in the beam. The performance of the monitor is compared to that of a standard BF3-monitor placed in the beam. Influences of a magnetic field on the photomultiplier of the Nal monitor is discussed, as well as the influence of activation gammas. At an instrument using a beam chopper the time behaviour is discussed.