Operation and first results of the NEXT-DEMO prototype using a silicon photomultiplier tracking array

Abstract

NEXT-DEMO is a high-pressure xenon gas TPC which acts as a technological testbed and demonstrator for the NEXT-100 neutrinoless double beta decay experiment. In its current configuration the apparatus fully implements the NEXT-100 design concept. This is an asymmetric TPC, with an energy plane made of photomultipliers and a tracking plane made of silicon photomultipliers (SiPM) coated with TPB. The detector in this new configuration has been used to reconstruct the characteristic signature of electrons in dense gas. Demonstrating the ability to identify the MIP and "blob" regions. Moreover, the SiPM tracking plane allows for the definition of a large fiducial region in which an excellent energy resolution of 1.82% FWHM at 511 keV has been measured (a value which extrapolates to 0.83% at the xenon Q β β ).

An improved measurement of electron-ion recombination in high-pressure xenon gas

“…Xenon de-excitation gives rise to the secondary scintillation light, with many photons produced per ionization electron. For further details about the NEXT-DEMO detector, see [33].…”

First proof of topological signature in the high pressure xenon gas TPC with electroluminescence amplification for the NEXT experiment

“…In a previous publication [7], only the average position of the track was reconstructed, using the barycentre calculated with the total integrated signal in each SiPM. The work presented here uses a more sophisticated algorithm to reconstruct the topology left in the detector by a charged particle.…”

“…The principle of operation of NEXT-100 and NEW and the necessary know-how has been developed using NEXT-DEMO, a large scale prototype which operated at the Instituto de Física Corpuscular in Valencia (Spain) with ∼1.5 kg of natural xenon at a pressure of 10 bar (for a detailed description of the prototype, see Refs. [6,7]).…”

Status and prospects of the NEXT experiment for neutrinoless double beta decay searches

“…The NEXT program is developing the technology of high-pressure xenon gas time projection chambers (TPCs) with electroluminescent amplification (HPXe-EL) for neutrinoless double beta decay searches (ββ0ν) [1][2][3]. The first phase of the program included the construction, commissioning and operation of two prototypes, called NEXT-DEMO and NEXT-DBDM (with masses of around 1 kg), which demonstrated the robustness of the technology, its excellent energy resolution and its unique topological signal [4][5][6][7]. The NEXT-White 1 demonstrator, deploying 5 kg of xenon, implements the second phase of the program.…”