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.
