Neutron beam imaging with micromegas detectors in combination with neutron time-of-flight at the n_tof facility at CERN

Abstract

A bulk micromegas detector with the anode segmented in 2 orthogonal directions and equipped with a neutron/charged particle converter is employed at the neutron time-of-light (nTOF) facility at CERN to determine the incident neutron beam profile and beam interception factor as a function of the neutron energy determined by the time of flight. Discrepancies between experimental results and simulations in the values of the beam interception factor range up to 12 % and are to be ascribed to a defect in the mesh of the bulk. Nevertheless the detector proved to be really useful for checking the alignment of the neutron beam optics of the facility. Measurements with a new pixelized bulk detector for the determination of the beam interception factor are forseen before the end of 2012