Gabriella Sciolla
MIT
Note different room and time
Thursday, November 5, 2009
2:00 pm in SPL 52
DMTPC: a novel apparatus for directional Dark Matter detection
Abstract: Directional detection is key to provide unambiguous observation of dark matter even in the presence of insidious backgrounds.
The DMTPC collaboration is developing a TPC with optical readout with the goal of detecting the sense and direction of the elastic recoils generated by Dark Matter interactions. The detector, filled with CF_4 gas at low pressure, is equipped with a mesh-based amplification region that allows for 2D imaging of the recoils in a CCD camera. The third coordinate of the recoil is provided by PMTs. The sense of the direction is determined by measuring the energy loss along the recoil track.
The performance of this detector has been studied using alpha particles, low-energy neutrons, and x-rays. Results from several prototypes have demonstrated the suitability of this approach to measure directionality by observing the "head-tail" effect for low- energy nuclear recoils.
A 10-liter DMTPC detector has recently been operated for three weeks in a surface run. Preliminary results from such a detector will be presented. A 20-liter detector is being built for underground operations at WIPP. A larger (1m^3) detector is also being designed. A one-year underground run with such a detector will allow us to improve the current sensitivity on spin-dependent interaction on protons by about a factor 50.