J. P. Lopez

First dark matter search results from a surface run of the 10-L DMTPC directional dark matter detector

Abstract The Dark Matter Time Projection Chamber (DMTPC) is a low pressure (75 Torr CF4) 10 liter detector capable of measuring the vector direction of nuclear recoils with the goal of directional dark matter detection. In this Letter we present the first dark matter limit from DMTPC from a surface run at MIT. In an analysis window of 80–200 keV recoil energy, based on a 35.7 g-day exposure, we set a 90% C.L. upper limit on the spin-dependent WIMP-proton cross section of 2.0 × 10 − 33 cm 2 for 115 GeV/c2 dark matter particle mass.

Readout technologies for directional WIMP Dark Matter detection

The measurement of the direction of WIMP-induced nuclear recoils is a compelling but technologically challenging strategy to provide an unambiguous signature of the detection of Galactic dark matter. Most directional detectors aim to reconstruct the dark-matter-induced nuclear recoil tracks, either in gas or solid targets. The main challenge with directional detection is the need for high spatial resolution over large volumes, which puts strong requirements on the readout technologies. In this paper we review the various detector readout technologies used by directional detectors. In particular, we summarize the challenges, advantages and drawbacks of each approach, and discuss future prospects for these technologies.

A prototype detector for directional measurement of the cosmogenic neutron flux

This paper describes a novel directional neutron detector. The low pressure time projection chamber uses a mix of helium and CF4 gases. The detector reconstructs the energy and angular distribution of fast neutron recoils. This paper reports results of energy calibration using an source and angular reconstruction studies using a collimated neutron source. The best performance is obtained with a 12.5% CF4 { 87.5% He gas mixture. At low energies the target for fast neutrons transitions is primarily helium, while at higher energies, the uorine contributes as a target. The reconstruction eciency is both energy and target dependent. For neutrons with energies less than 20 MeV, the reconstruction eciency is 40% for uorine recoils and 60% for helium recoils.

Results from DMTPC 10-liter detector

The known direction of motion of dark matter particles relative to the Earth may be a key for their unambiguous identification even in the presence of backgrounds. A direction-sensitive detector prototype using a low-density CF4 gas with a 10 liter fiducial volume is operated for several weeks in a basement laboratory. We present initial results that confirm good detector performance and set preliminary limits on spin-dependent dark matter interactions.

DMTPC: A dark matter detector with directional sensitivity

By correlating nuclear recoil directions with the Earth’s direction of motion through the Galaxy, a directional dark matter detector can unambiguously detect Weakly Interacting Massive Particles (WIMPs), even in the presence of backgrounds. Here, we describe the Dark Matter Time‐Projection Chamber (DMTPC) detector, a TPC filled with CF4 gas at low pressure (0.1 atm). Using this detector, we have measured the vector direction (head‐tail) of nuclear recoils down to energies of 100 keV with an angular resolution of ≤15°. To study our detector backgrounds, we have operated in a basement laboratory on the MIT campus for several months. We are currently building a new, high‐radiopurity detector for deployment underground at the Waste Isolation Pilot Plant facility in New Mexico.

The DMTPC detector

Directional Dark Matter detectors have the potential of yielding an unambiguous observation of WIMPs even in presence of insidious background. In addition, by measuring the direction of the Dark Matter particles such detectors can discriminate between the various models that describe Dark Matter in our galaxy. The DMTPC detector is a novel directional DM detector consisting of a low-pressure CF4 time projection chamber with optical readout. Recent measurements proved that this technology is able to reconstruct the energy, direction, and sense of the lowenergy nuclear recoils produced by neutrons from a 252Cf source, as well as efficiently reject electromagnetic backgrounds. A 10-liter DMTPC detector is ready for underground operation. A 1 m3 detector, now in the design phase, will soon allow us to improve the existing limits of SD-interactions of WIMPs on protons by over one order of magnitude.

Measurement of the directional sensitivity of Dark Matter Time Projection Chamber detectors

Cosmin Deaconu, ∗ Michael Leyton, † Ross Corliss, Gabriela Druitt, Richard Eggleston, Natalia Guerrero, ‡ Shawn Henderson, § Jeremy Lopez, ¶ Jocelyn Monroe, and Peter Fisher Physics Department, and Laboratory for Nuclear Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 Royal Holloway University of London, Department of Physics, Egham, Surrey TW20 0EX, United Kingdom Physics Department, Institute for Soldier Nanotechnology, MIT Kavli Institute and, Laboratory for Nuclear Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139∗∗ (Dated: May 31, 2017)