Characterization of multilayer Thick-GEM geometries as ¹⁰B converters aiming thermal neutron detection

¹ Instituto de Física, Universidade de São Paulo, Brasil
² Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP, São Paulo, Brasil

^a e-mail: hugonluz@if.usp.br

Published online: 21 February 2018

Abstract

Boron-based thermal neutron detectors have recently regained some attention from the instrumentation community as a strong alternative to helium-3 detectors. From the existing concepts exploiting boron layers in position sensitive detectors, the Cascade [1] is the one that takes full advantage of the 2D capabilities of gaseous detectors, with the position resolution not limited by the architecture of the detector. In this work, a proposal for the Cascade detector, based on Thick-GEMs is presented, together with some preliminary studies of the suitable pitch that optimizes the neutron conversion efficiency, while keeping the collection efficiency intact. The characterization of Thick-GEM prototypes produced in Brazil with hole pitch from 0.75 to 3 mm shows that these devices already present a stable performance at low gains, also resulting in fair energy resolution, when cascaded with a standard Kapton^TM 50 µm GEM. Results of the first attempts of boron film depositions with Ion Beam Assisted Deposition and characterization by Ion Beam Analysis are also presented.