Optimisation of the scintillation light collection and uniformity of the SoLid experiment

Yamiel Abreu, Yasmine Amhis, Wim Beaumont, Mathieu Bongrand, B.C. Castle, Keith Clark, Bernard Coupé, David Cussans, Albert De Roeck, D. Durand, M. Fallot, Lars Ghys, L. Giot, Kyle Graves, Benoit Guillon, David Henaff, Behzad Hosseini, Sakari Ihantola, S. Jenzer, Silva KalchevaLeonidas Kalousis, Mathieu Labare, Gregory Lehaut, Steve Manley, Luis Manzanillas, Jeroen Mermans, Jeroen Mermans, Ianthe Michiels, Celine Moortgat, Dave Newbold, Jaewon Park, Valentin Pestel, K. Petridis, Ibrahin Pinera, Lucia Popescu, Dirk Ryckbosch, Nick Ryder, Daniel Saunders, M.-H. Schune, Settimo M., Laurent Simard, Antonin Vacheret, Giel Vandierendonck, Steven Van Dyck, Petra Van Mulders, Nick Van Remortel, Simon Vercaemer, Verstraeten Maja, Benoit Viaud, Alfons Weber, Frederic Yermia

Research outputpeer-review

Abstract

This paper presents a comprehensive optimisation study to maximise the light collection efficiency of scintillating cube elements used in the SoLid detector. Very short baseline reactor experiments, like SoLid, look for active to sterile neutrino oscillation signatures in the anti-neutrino energy spectrum as a function of the distance to the core and energy. Performing a precise search requires high light yield of the scintillating elements and uniformity of the response in the detector volume. The SoLid experiment uses an innovative hybrid technology with two different scintillators: polyvinyltoluene scintillator cubes and 6LiF:ZnS(Ag) screens. A precision test bench based on a 207Bi calibration source has been developed to study improvements on the energy resolution and uniformity of the prompt scintillation signal of antineutrino interactions. A trigger system selecting the 1 MeV conversion electrons provides a Gaussian energy peak and allows for precise comparisons of the different detector configurations that were considered to improve the SoLid detector light collection. The light collection efficiency is influenced by the choice of wrapping material, the position of the 6LiF:ZnS(Ag) screen, the type of fibre, the number of optical fibres and the type of mirror at the end of the fibre. This study shows that large gains in light collection efficiency are possible compared to the SoLid SM1 prototype. The light yield for the SoLid detector is expected to be at least 522 photo-avalanches per MeV per cube, with a relative non-uniformity of 6 %, demonstrating that the required energy resolution of at least 14 % at 1 MeV can be achieved.
Original languageEnglish
Article numberP09005
Pages (from-to)1-24
Number of pages24
JournalJournal of Instrumentation
Volume13
Issue number9
StatePublished - 7 Sep 2018

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