Mitigation of Backgrounds from Cosmogenic $^{137}$Xe in Xenon Gas Experiments using $^{3}$He Neutron Capture
L. Rogers, B. J. P. Jones, A. Laing, S. Pingulkar, K. Woodruff, C. Adams, V. Álvarez, L. Arazi, I. J. Arnquist, C. D. R Azevedo, K. Bailey, F. Ballester, J. M. … 展开作者
L. Rogers, B. J. P. Jones, A. Laing, S. Pingulkar, K. Woodruff, C. Adams, V. Álvarez, L. Arazi, I. J. Arnquist, C. D. R Azevedo, K. Bailey, F. Ballester, J. M. Benlloch-Rodríguez, F. I. G. M. Borges, N. Byrnes, S. Cárcel, J. V. Carrión, S. Cebrián, E. Church, C. A. N. Conde, T. Contreras, G. Díaz, J. Díaz, M. Diesburg, R. Dingler, J. Escada, R. Esteve, R. Felkai, A. F. M. Fernandes, L. M. P. Fernandes, P. Ferrario, A. L. Ferreira, E. D. C. Freitas, J. Generowicz, S. Ghosh, A. Goldschmidt, J. J. Gómez-Cadenas, D. González-Díaz, R. Guenette, R. M. Gutiérrez, J. Haefner, K. Hafidi, J. Hauptman, C. A. O. Henriques, J. A. Hernando Morata, P. Herrero, V. Herrero, Y. Ifergan, S. Johnston, M. Kekic, L. Labarga, P. Lebrun, N. López-March, M. Losada, R. D. P. Mano, J. Martín-Albo, A. Martínez, G. Martínez-Lema, A. D. McDonald, F. Monrabal, C. M. B. Monteiro, F. J. Mora, J. Muñoz Vidal, P. Novella, D. R. Nygren, B. Palmeiro, A. Para, J. Pérez, M. Querol, A. B. Redwine, J. Renner, J. Repond, S. Riordan, L. Ripoll, Y. Rodríguez García, J. Rodríguez, B. Romeo, C. Romo-Luque, F. P. Santos, J. M. F. dos Santos, A. Simón, C. Sofka, M. Sorel, T. Stiegler, J. F. Toledo, J. Torrent, A. Usón, J. F. C. A. Veloso, R. Webb, R. Weiss-Babai, J. T. White, N. Yahlali
\Xe{136} is used as the target medium for many experiments searching for \bbnonu. Despite underground operation, cosmic muons that reach the laboratory can produce spallation neutrons causing activation of detector materials. A potential background that is difficult to veto using muon tagging comes in the form of \Xe{137} created by the capture of neutrons on \Xe{136}. This isotope decays via beta decay with a half-life of 3.8 minutes and a \Qb\ of $\sim$4.16 MeV. This work proposes and explores the concept of adding a small percentage of \He{3} to xenon as a means to capture thermal neutrons and reduce the number of activations in the detector volume. When using this technique we find the contamination from \Xe{137} activation can be reduced to negligible levels in tonne and multi-tonne scale high pressure gas xenon neutrinoless double beta decay experiments running at any depth in an underground laboratory.
XENON1T recently reported an excess of low-energy electron recoil events that may be attributable to either new physics or to the radioactive decay of tritium. It is likely that hydrogen is not be effectively removed by the hot zirconium getters deployed in the detector. Cosmogenic activation of the xenon underground is found to be insufficient to describe the observed excess, although gases diffusing out of detector materials from cosmogenic activation on surface may contribute. Changes in the operation of gas purification systems for XENON1T and other liquid nobel gas detectors could both co…
Muon-induced neutrons can lead to potentially irreducible backgrounds in rare event search experiments. We have investigated the implication of laboratory depth on the muon induced background in a future dark matter experiment capable of reaching the so-called neutrino floor. Our simulation study focuses on a xenon-based detector with 71 tonnes of active mass, surrounded by additional veto systems including an instrumented water shield. Two locations at the Boulby Underground Laboratory (UK) served as a case study: an experimental cavern in salt at a depth of 2850 m w.e. (similar to the locati…
Double beta decay is a very rare nuclear process and, therefore, experiments intended to detect it must be operated deep underground and in ultra-low background conditions. Long-lived radioisotopes produced by the previous exposure of materials to cosmic rays on the Earth's surface or even underground can become problematic for the required sensitivity. Here, the studies developed to quantify and reduce the activation yields in detectors and materials used in the set-up of these experiments will be reviewed, considering target materials like germanium, tellurium and xenon together with other o…
We characterize single- and few-electron backgrounds that are observed in dual-phase liquid xenon time projection chambers at timescales greatly exceeding a maximum drift time after an interaction. These instrumental backgrounds limit a detector's sensitivity to dark matter and cosmogenic neutrinos. Using the ~150g liquid xenon detector at Purdue University, we investigate how these backgrounds, produced after 122keV $^{57}$Co Compton interactions, behave under different detector conditions. We find that the rates of single- and few-electron signals follow power-laws with time after the intera…
The KamLAND-Zen 800 experiment is searching for the neutrinoless double-beta decay of $^{136}$Xe by using $^{136}$Xe-loaded liquid scintillator. The liquid scintillator is enclosed inside a balloon made of thin, transparent, low-radioactivity film that we call Inner Balloon (IB). The IB, apart from guaranteeing the liquid containment, also allows to minimize the background from cosmogenic muon-spallation products and $^{8}$B solar neutrinos. Indeed these events could contribute to the total counts in the region of interest around the Q-value of the double-beta decay of $^{136}$Xe. In this pape…
This paper presents a novel technique for mitigating electrode backgrounds that limit the sensitivity of searches for low-mass dark matter (DM) using xenon time projection chambers. In the LUX detector, signatures of low-mass DM interactions would be very low energy ($\sim$keV) scatters in the active target that ionize only a few xenon atoms and seldom produce detectable scintillation signals. In this regime, extra precaution is required to reject a complex set of low-energy electron backgrounds that have long been observed in this class of detector. Noticing backgrounds from the wire grid ele…
Low-Energy Radon Backgrounds from Electrode Grids in Dual-Phase Xenon TPCs
SLAC National Accelerator Laboratory（斯坦福直线加速器中心）；Kavli Institute for Particle Astrophysics and Cosmology, Stanford University（卡弗里粒子天体物理与宇宙学研究所，斯坦福大学）；University College London (UCL)（伦敦大学学院）；Brown University（布朗大学）；University of Wisconsin-Madison（威斯康星大学麦迪逊分校）；University of California, Santa Barbara（加州大学圣塔芭芭拉分校）；Imperial College London（帝国理工学院）；University of Maryland（马里兰大学）
