Directional detection of dark matter can provide unambiguous
observation of dark matter (DM) interactions even in the presence of
insidious backgrounds.
The DM-TPC collaboration is developing a detector with the goal
of measuring the direction and sense ("head-tail") of nuclear recoils
produced in spin-dependent DM interactions.
The detector consists of a low pressure TPC with optical readout
filled with CF4 gas at low pressure. A collision between a WIMP with
a gas molecule results in a nucleus recoil of 1-2 mm. The
measurement of the energy loss along the recoil allows us to
determine the sense and the direction of the recoil.
Results from a prototype detector operated in a low-energy neutron beam
clearly demonstrate the suitability of this approach to measure directionality.
In particular, the first observation of the "head-tail" effect for low-energy
neutrons
had been recently published by our Collaboration.
A full-scale (1m^3) module is now being designed. This detector, which
will be operated underground in 2009, will allow us to set limits on
spin-dependent Dark Matter interactions using a directional detector.
The sensitivity of this experiment will be discussed in this talk. |