Calorimeter development for the SuperNEMO double beta decay experiment

Abstract

SuperNEMO is a double-β decay experiment, which will employ the successful tracker–calorimeter technique used in the recently completed NEMO-3 experiment. SuperNEMO will implement 100 kg of double-β decay isotope, reaching a sensitivity to the neutrinoless double-β decay (0νββ) half-life of the order of 1026 yr, corresponding to a Majorana neutrino mass of 50–100 meV. One of the main goals and challenges of the SuperNEMO detector development programme has been to reach a calorimeter energy resolution, ΔE∕E, around 3%∕E(MeV) σ, or 7%∕E(MeV) FWHM (full width at half maximum), using a calorimeter composed of large volume plastic scintillator blocks coupled to photomultiplier tubes. We describe the R&D programme and the final design of the SuperNEMO calorimeter that has met this challenging goal

Radioactive contamination of scintillators

“…[45] Large-scale scintillator-based projects to search for neutrinoless double β decay with sensitivity on the level of the inverted hierarchy of the neutrino masses have been proposed [46,47,48]. In this regard, it is of note that the SuperNEMO double β decay project [49] intents to utilize a large amount of plastic scintillators for the calorimeter of the detector [50].…”

Main features of detectors and isotopes to investigate double beta decay with increased sensitivity

“…Planed energy resolution is 4% (FWHM) at 3 MeV and planed detection efficiency for 0νββ decay is ∼ 30%. More detailed information one can find in [81,82]. The SuperNEMO Demonstrator should start data taking in 2018.…”

Search for neutrinoless double-beta decay with the SuperNEMO demonstrator

“…Each calorimeter module is composed of 520 Optical Modules (OMs) made of plastic scintillator (Polystyrene) coupled to 8" and 5" PhotoMultiplier Tubes (PMTs). Thanks to a successfull R&D effort based on dedicated optical simulations, the energy resolution of the optical modules is on average 8-8.3% (full width at half maximum) [4] and the time resolution is about 400 ps at 1 MeV (see fig. 2).…”