Characterization of a medium size Xe/TMA TPC instrumented with microbulk Micromegas, using low-energy $\gamma$-rays
Abstract
NEXT-MM is a general-purpose high pressure (10 bar, l active volume) Xenon-based TPC, read out in charge mode with an 8 cm 8 cm-segmented 700 cm plane (1152 ch) of the latest microbulk-Micromegas technology. It has been recently commissioned at University of Zaragoza as part of the R&D of the NEXT experiment, although the experiment's first stage is currently being built based on a SiPM/PMT-readout concept relying on electroluminescence. Around 2 million events were collected during the last months, stemming from the low energy -rays emitted by a Am source when interacting with the Xenon gas ( = 26, 30, 59.5 keV). The localized nature of such events above atmospheric pressure, the long drift times, as well as the possibility to determine their production time from the associated particle in coincidence, allow the extraction of primordial properties of the TPC filling gas, namely the drift velocity, diffusion and attachment coefficients. In this work we focus on the little explored combination of Xe and trimethylamine (TMA) for which, in particular, such properties are largely unknown. This gas mixture offers potential advantages over pure Xenon when aimed at Rare Event Searches, mainly due to its Penning characteristics, wave-length shifting properties and reduced diffusion, and it is being actively investigated by our collaboration. The chamber is currently operated at 2.7 bar, as an intermediate step towards the envisaged 10 bar. We report here its performance as well as a first implementation of the calibration procedures that have allowed the extension of the previously reported energy resolution to the whole readout plane (10.6%FWHM@30keV).
Keywords
Cite
@article{arxiv.1311.3535,
title = {Characterization of a medium size Xe/TMA TPC instrumented with microbulk Micromegas, using low-energy $\gamma$-rays},
author = {The NEXT collaboration and V. Alvarez and F. I. G. M. Borges and S. Carcel and J. Castel and S. Cebrian and A. Cervera and C. A. N. Conde and T. Dafni and T. H. V. T. Dias and J. Diaz and M. Egorov and R. Esteve and P. Evtoukhovitch and L. M. P. Fernandes and P. Ferrario and A. L. Ferreira and E. D. C. Freitas and V. M. Gehman and A. Gil and A. Goldschmidt and H. Gomez and J. J. Gomez-Cadenas and D. Gonzalez-Diaz and R. M. Gutierrez and J. Hauptman and J. A. Hernando Morata and D. C. Herrera and F. J. Iguaz and I. G. Irastorza and M. A. Jinete and L. Labarga and A. Laing and I. Liubarsky and J. A. M. Lopes and D. Lorca and M. Losada and G. Luzon and A. Mari and J. Martin-Albo and A. Martinez and G. Martinez-Lema and T. Miller and A. Moiseenko and F. Monrabal and C. M. B. Monteiro and F. J. Mora and L. M. Moutinho and J. Munoz Vidal and H. Natal da Luz and G. Navarro and M. Nebot-Guinot and D. Nygren and C. A. B. Oliveira and R. Palma and J. Perez and J. L. Perez Aparicio and J. Renner and L. Ripoll and A. Rodriguez and J. Rodriguez and F. P. Santos and J. M. F. dos Santos and L. Segui and L. Serra and D. Shuman and A. Simon and C. Sofka and M. Sorel and J. F. Toledo and A. Tomas and J. Torrent and Z. Tsamalaidze and D. Vazquez and J. F. C. A. Veloso and J. A. Villar and R. C. Webb and J. T. White and N. Yahlali and F. Aznar and D. Calvet and F. Druillole and E. Ferrer-Ribas and J. A. Garcia and I. Giomataris and J. Gracia and A. Le Coguie and J. P. Mols and P. Pons and E. Ruiz},
journal= {arXiv preprint arXiv:1311.3535},
year = {2015}
}
Comments
22 pages, 13 figures