The Dark Matter Time Projection Chamber (DMTPC) collaboration is developing low-pressure gas TPC detectors for measuring WIMP-nucleon interactions. Optical readout with CCD cameras allows for the detection for the daily modulation in the direction of
the dark matter wind, while several charge readout channels allow for the measurement of additional recoil properties. In this article, we show that the addition of the charge readout analysis to the CCD allows us too obtain a statistics-limited 90% C.L. upper limit on the $e^-$ rejection factor of $5.6times10^{-6}$ for recoils with energies between 40 and 200 keV$_{mathrm{ee}}$. In addition, requiring coincidence between charge signals and light in the CCD reduces CCD-specific backgrounds by more than two orders of magnitude.
The DMTPC detector is a low-pressure CF4 TPC with optical readout for directional detection of Dark Matter. The combination of the energy and directional tracking information allows for an efficient suppression of all backgrounds. The choice of gas (
CF4) makes this detector particularly sensitive to spin-dependent interactions.
Directional detection of Dark Matter allows for unambiguous direct detection of WIMPs as well as discrimination between various Dark Matter models in our galaxy. The DMTPC detector is a low-pressure TPC with optical readout designed for directional d
irect detection of WIMPs. By using CF4 gas as the active material, the detector also has excellent sensitivity to spin-dependent interactions of Dark Matter on protons.
Directional detection of Dark Matter allows for unambiguous direct detection of WIMPs as well as discrimination between various Dark Matter models in our galaxy. The DMTPC detector is a low-pressure TPC with optical readout designed for directional d
irect detection of WIMPs. By using CF4 gas as the active material, the detector also has excellent sensitivity to spin-dependent interactions of Dark Matter on protons.
