Abstract
Recent computational results suggest that directional dark matter
detectors have potential to probe for WIMP dark matter particles below
the neutrino floor. The DRIFT-IId detector used in this work is a
leading directional WIMP search time projection chamber detector. We
report the first measurements of the detection of the directional
nuclear recoils in a fully fiducialised low-pressure time projection
chamber. In this new operational mode, the distance between each event
vertex and the readout plane is determined by the measurement of
minority carriers produced by adding a small amount of oxygen to the
nominal CS2+CF4 target gas mixture. The
CS2+CF4+O2 mixture has been shown to
enable background-free operation at current sensitivities. Sulfur,
fluorine, and carbon recoils were generated using neutrons emitted from
a 252Cf source positioned at different locations around the
detector. Measurement of the relative energy loss along the recoil
tracks allowed the track vector sense, or the so-called head-tail
asymmetry parameter, to be deduced. Results show that the previously
reported observation of head-tail sensitivity in pure CS2 is
well retained after the addition of oxygen to the gas mixture.
Original language | English |
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Article number | P10019 |
Journal | Journal of Instrumentation |
Volume | 11 |
Issue number | 10 |
DOIs | |
Publication status | Published - 27 Oct 2016 |