TREX-DM: a low-background Micromegas-based TPC for low-mass WIMP detection

Area of Science:

• Particle Physics
• Cosmology
• Experimental Nuclear Physics

Background:

• Current dark matter searches face challenges with low-mass Weakly Interacting Massive Particles (WIMPs) due to experimental energy thresholds.
• Gas Time Projection Chambers (TPCs) offer potential for lower thresholds and versatile target selection.
• Advances in radiopure materials and micro-mesh gas structure (Micromegas) enhance TPC capabilities for low-background experiments.

Purpose of the Study:

• To present TREX-DM, a prototype Micromegas-based TPC designed for the detection of low-mass WIMPs.
• To evaluate the feasibility and sensitivity of this TPC technology for dark matter detection.
• To explore potential improvements in WIMP detection beyond current experimental limits.

Main Methods:

• Development and testing of the TREX-DM prototype, a gas TPC employing Micromegas technology.
• Detector operation with Argon or Neon gas at 10 bar, achieving an energy threshold below 0.4 keVee.
• Utilizing radiopure materials throughout the detector construction to minimize background noise.

Main Results:

• Successful commissioning of the TREX-DM prototype on the surface.
• Development of a preliminary background model for the detector.
• Anticipated sensitivity potentially exceeding current limits for WIMPs in the 2-8 GeV mass range.

Conclusions:

• Micromegas-based gas TPCs represent a promising technology for searching for low-mass WIMPs.
• The TREX-DM prototype demonstrates the potential for achieving very low energy thresholds and good scalability.
• This approach could significantly advance dark matter detection capabilities.