Piccolo Micromegas: First in-core measurements in a nuclear reactor

Abstract

An Accelerator Driven System (ADS) consists in the coupling of an accelerator with a nuclear reactor. Such systems will need neutron detectors working in a wide energy range and insensitive to X-and γ-rays. Micromegas technology has been proposed to achieve this goal. The ability of Micromegas to detect neutrons over a wide energy range has already been demonstrated and this detector is, under certain conditions, insensitive to γ-rays. A new Micromegas neutron detector called Piccolo Micromegas has been designed to get integrated neutron fluxes on different energy domains. For the first time, Piccolo Micromegas has been placed in the core of a nuclear reactor at Casaccia in Italy. The configuration of the detector will be presented as well as its functioning and the reasons of its insensitivity to γ-rays.The results of the operation of the detector will also be shown for low reactor power to high reactor power ans some improvements will be suggested.

Detector design and performance tests of the ESS-neutron Beam Loss Monitor detectors

“…They can also be adapted to different neutron applications with the appropriate use of neutron-to-charge converters and neutron absorbers and moderators [17,18]. They have been used in different applications requiring neutron detection, from neutron physics in ToF experiments [19], to fusion studies [20] and measurements inside the core of nuclear reactors [21].…”

10B4C Multi-Grid as an Alternative to 3He for Large Area Neutron Detectors

“…Contrary to gaseous converters, when an energy threshold is set neutron events of an energy lower than the threshold will be lost which will decrease the detection eciency. Due to its low eciency, mono-layer boron-containing detectors have been used for beam-monitoring [15]. In order to reach detection eciencies comparable to 3 He-based detectors a relatively thick layer of a boron-containing material is needed.…”

“…For a γ-ray, the linear attenuation coecient, µ, can be dened as a function of σ γ tot : 15) where N A is the Avogadro's number, A the atomic weight of the absorber medium and ρ its density.…”

Investigating the response of Micromegas detector to low-energy neutrons using Monte Carlo simulation

“…These precise detectors have been developed by different researchers to detect electron, proton, neutron, alpha, etc. and offer spatial resolutions less than 0.01 mm [10][11][12].…”