  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. We describe a prototype detector that is able to reconstruct
direction vectors of weakly interacting massive particles that may the dominant
constituent of the dark matter in our galaxy. The detector uses a low-density
gas (CF4) in a 10liter time-projection chamber with mesh-based electrodes and
optical and charge readout. Initial results confirm good performance in the
reconstruction of direction angle and sense ('head-tail') for low-momentum
nuclear recoils.
