Speaker
Mr
Bruno Guerard
(ILL)
Description
3He is often used as the neutron convertor for detectors in neutron scattering science, but this gas has become rare and very expensive since 2008. The growing lack of Large Area Neutron Detectors becoming a major concern in most of the research neutron institutes, the development of techniques based on alternative convertors is of the highest priority. 10B is another popular neutron convertor which can be used either in solid scintillators, or in proportional counters as thin films (10B or 10B4C) or gas compound (10BF3). In the so-called Multi-Grid detector, the volume of the detector is filled with grids, electrically insulated and stacked together to form square tubes. Each tube has a wire at its centre for charge collection and gas amplification. The mechanics of this design allows building large area vacuum compatible detectors with no dead space. In a 10B Multi-Grid detector, one grid consists of blades coated with thin Boron films on both sides mounted on a frame, whereas in a 10BF3 Multi-Grid detector, one grid is made of a single block of Aluminium, machined to create the holes. A 10B Multi-Grid prototype with 30 layers of B4C has been tested on a monochromatic neutron beam line. The absorption profile through the detection planes has been measured for films containing natB and 10B. Preliminary results agree with the simulated performance, and show that this technique allows to reach a detection efficiency > 50% for thermal neutrons.
Primary author
Mr
Bruno Guerard
(ILL)
