Suchergebnisse

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 (LiF)-Li-6:ZnS(Ag) screens. A precision test bench based on a Bi-207 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 52 +/- 2 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. ; Agence Nationale de la Recherche grant [ANR-16CE31001803]; Institut Carnot Mines; Region Pays de Loire in France; FWO-Vlaanderen; Vlaamse Herculesstichting in Belgium; Science&Technology Facilities Council (STFC); CNRS/IN2P3; Belgian Federal Science Policy Office (BelSpo) under the IUAP network programme; European Research Council under the European Union's Horizon 2020 Programme (H2020-CoG)/ERC Grant [682474] ; This work was supported by the following funding agencies: Agence Nationale de la Recherche grant ANR-16CE31001803, Institut Carnot Mines, CNRS/IN2P3 and Region Pays de Loire in France and FWO-Vlaanderen and the Vlaamse Herculesstichting in Belgium. The United Kingdom groups acknowledge the support of the Science&Technology Facilities Council (STFC). We are grateful for the early support given by the sub-department of Particle Physics and Merton College at Oxford and High Energy Physics at Imperial College London. We thank also our colleagues, the administrative and technical staffs of the SCK center dot CEN for their invaluable support for this project. Individuals have received support from the FWO-Vlaanderen and the Belgian Federal Science Policy Office (BelSpo) under the IUAP network programme. The STFC Rutherford Fellowship program and the European Research Council under the European Union's Horizon 2020 Programme (H2020-CoG)/ERC Grant Agreement n. 682474.