Professor Jocelyn Monroe

Abstract:

The Dark Matter Time Projection Chamber (DMTPC) collaboration is developing prototype detectors to measure both the energies and directions of nuclear recoils. The intended application is to exploit the expected directional anisotropy of dark matter velocities at Earth to unambiguously observe dark matter induced recoils. The detector consist of low-pressure CF4 TPC's with CCD cameras, PMT's, and charge amplifiers for readout. This talk gives an overview of the experiment and describes recent advances in hardware and analysis.

Abstract:

Coherent scattering of solar, atmospheric, and diffuse supernovae neutrinos creates an irreducible background for direct dark matter experiments with sensitivities to WIMP-nucleon spin-independent scattering cross sections of 10-46-10-48cm2, depending on the WIMP mass. Even if one could eliminate all other backgrounds, this "neutrino floor" will limit future experiments with projected sensitivities to cross sections as small as 10-48cm2. Direction-sensitive detectors have the potential to study dark matter beyond the neutrino bound by fitting event distributions in multiple dimensions: recoil kinetic energy, recoil track angle with respect to the sun, and event time. This work quantitatively explores the impact of direction sensitivity on the neutrino bound in dark matter direct detection.

Abstract:

The 4Shooter is a prototype dark matter detector built by the Dark Matter Time Projection Chamber (DMTPC) collaboration. The aim of the collaboration is to observe dark matter with directional sensitivity by measuring the recoil directions of nuclei struck by dark matter particles. The 4Shooter is a single time projection chamber containing CF4 gas, with both optical (CCD and photomultiplier tube) and charge readout. This paper describes the 4Shooter and presents results from the commissioning of the detector in a surface laboratory. © 2014 Elsevier B.V.