Measurement of the neutron flux at spallation sources using multi-foil activation

作者：Chiesa Davide^*; Nastasi Massimiliano; Cazzaniga Carlo; Rebai Marica; Arcidiacono Laura; Previtali Ezio; Gorini Giuseppe; Frost Christopher D

来源：Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment , 2018, 902: 14-24.

DOI：10.1016/j.nima.2018.06.016

• Neutron spectrum unfolding
• Activation analysis
• Fast neutrons
• Spallation sources
• Gamma-ray and neutron spectroscopy

Activation analysis is used in this work to measure the flux of a fast neutron beamline at a spallation source over a wide energy spectrum, extending from thermal to hundreds of MeV. The experimental method is based on the irradiation of multiple elements and measurements of activation gamma-lines using a High Purity Germanium detector. The method for data analysis is then described in detail, with particular attention to the evaluation of uncertainties. The reactions have been chosen so to cover the whole energy range, using mainly (n, gamma)for thermal and epithermal neutrons, and threshold reactions for the fast region. The variety of these reactions allowed for the unfolding of the neutron spectrum, using an algorithm based on a Bayesian statistical model, and limited correlations have been found between the energy groups.

• 出版日期2018-9-11