TREX-DM: a low-background Micromegas-based TPC for low-mass WIMP detection.
If Dark Matter is made of Weakly Interacting Massive Particles (WIMPs) with masses below [Formula: see text] GeV, the corresponding nuclear recoils in mainstream WIMP experiments are of energies too close, or below, the experimental threshold. Gas Time Projection Chambers (TPCs) can be operated with a variety of target elements, offer good tracking capabilities and, on account of the amplification in gas, very low thresholds are achievable. Recent advances in electronics and in novel radiopure TPC readouts, especially micro-mesh gas structure (Micromegas), are improving the scalability and low-background prospects of gaseous TPCs. Here we present TREX-DM, a prototype to test the concept of a Micromegas-based TPC to search for low-mass WIMPs. The detector is designed to host an active mass of [Formula: see text] kg of Ar at 10 bar, or alternatively [Formula: see text] kg of Ne at 10 bar, with an energy threshold below 0.4 keVee, and is fully built with radiopure materials. We will describe the detector in detail, the results from the commissioning phase on surface, as well as a preliminary background model. The anticipated sensitivity of this technique may go beyond current experimental limits for WIMPs of masses of 2-8 GeV.
Grupo de Física Nuclear y Astropartículas, Universidad de Zaragoza, C/Pedro Cerbuna 12, 50009 Zaragoza, Spain.
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Iguaz
Grupo de Física Nuclear y Astropartículas, Universidad de Zaragoza, C/Pedro Cerbuna 12, 50009 Zaragoza, Spain.
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Garza
Grupo de Física Nuclear y Astropartículas, Universidad de Zaragoza, C/Pedro Cerbuna 12, 50009 Zaragoza, Spain ; Centro Universitario de la Defensa, Universidad de Zaragoza, Crta. de Huesca s/n, 50090 Zaragoza, Spain.
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Aznar
Grupo de Física Nuclear y Astropartículas, Universidad de Zaragoza, C/Pedro Cerbuna 12, 50009 Zaragoza, Spain.
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Castel
Grupo de Física Nuclear y Astropartículas, Universidad de Zaragoza, C/Pedro Cerbuna 12, 50009 Zaragoza, Spain.
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Cebrián
Grupo de Física Nuclear y Astropartículas, Universidad de Zaragoza, C/Pedro Cerbuna 12, 50009 Zaragoza, Spain.
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Dafni
Grupo de Física Nuclear y Astropartículas, Universidad de Zaragoza, C/Pedro Cerbuna 12, 50009 Zaragoza, Spain.
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García
Grupo de Física Nuclear y Astropartículas, Universidad de Zaragoza, C/Pedro Cerbuna 12, 50009 Zaragoza, Spain.
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Irastorza
Grupo de Física Nuclear y Astropartículas, Universidad de Zaragoza, C/Pedro Cerbuna 12, 50009 Zaragoza, Spain.
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Lagraba
Grupo de Física Nuclear y Astropartículas, Universidad de Zaragoza, C/Pedro Cerbuna 12, 50009 Zaragoza, Spain.
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Luzón
Grupo de Física Nuclear y Astropartículas, Universidad de Zaragoza, C/Pedro Cerbuna 12, 50009 Zaragoza, Spain.
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Peiró