A large high-efficiency multi-layered Micromegas thermal neutron detector. (8th September 2017)

• Record Type: Journal Article
• Authors: Tsiledakis, G.; Delbart, A.; Desforge, D.; Giomataris, I.; Menelle, A.; Papaevangelou, T.
• Is Part Of: Journal of instrumentation. Volume 12:Number 9(2017:Sep.)
• Page Start: P09006
• Page End: P09006
• Publication Date: 2017-09-08
• Subjects: Detector modelling and simulations I (interaction of radiation with matter, interaction of photons with matter, interaction of hadrons with matter, etc) -- Gaseous detectors -- Micropattern gaseous detectors (MSGC, GEM, THGEM, RETHGEM, MHSP, MICROPIC, MICROMEGAS, InGrid, etc) -- Neutron detectors (cold, thermal, fast neutrons); Scientific apparatus and instruments -- Periodicals; 502.84
• DOI: 10.1088/1748-0221/12/09/P09006
• Languages: English
• ISSNs: 1748-0221

Abstract

Abstract: Due to the so-called 3 He shortage crisis, many detection techniques used nowadays for thermal neutrons are based on alternative converters. Thin films of 10 B or 10 B 4 C are used to convert neutrons into ionizing particles which are subsequently detected in gas proportional counters, but only for small or medium sensitive areas so far. The micro-pattern gaseous detector Micromegas has been developed for several years in Saclay and is used in a wide variety of neutron experiments combining high accuracy, high rate capability, excellent timing properties and robustness. We propose here a large high-efficiency Micromegas-based neutron detector with several 10 B 4 C thin layers mounted inside the gas volume for thermal neutron detection. The principle and the fabrication of a single detector unit prototype with overall dimension of ∼ 15 × 15 cm 2 and a flexibility of modifying the number of layers of 10 B 4 C neutron converters are described and simulated results are reported, demonstrating that typically five 10 B 4 C layers of 1–2 μ m thickness can lead to a detection efficiency of 20–40% for thermal neutrons and a spatial resolution of sub-mm. The design is well adapted to large sizes making possible the construction of a mosaic of several such detector units with a large area coverage and a high detection efficiency, showing the good potential of this novel technique.