Last updated:06/13/11

Abstract:

In the research effort to determine the nature of dark matter, direct detection experiments such as the Cryogenic Dark Matter Search (CDMS) are attempting to detect the rare interaction of weakly interacting dark matter particles with conventional matter. I will outline the basic physics of dark matter detection with CDMS as well as the recent progress in developing and testing the next generation of CDMS detectors . The detector development process is supported by a Detector Monte Carlo (DMC) model which allows optimization of detector parameters across a vast parameter space. The DMC has to correctly model the anisotropic phonon propagation inside the detector crystal, as well as the propagation of slow electrons and holes. I will discuss the physics of the CDMS Monte Carlo model and our efforts to implement a full version of the DMC using the publicly available geant4 toolkit. This implementation will constitute the first condensed matter framework for geant4. Implementing our Monte Carlo model in geant4 ensures that the wider scientific community can benefit from our work. The geant4 toolkit was originally developed for high-energy physics to simulate the transport of particles through matter. Geant4 has also been used for nuclear and accelerator physics, and applications in medical and space sciences. We believe that with our current work, we may open up new avenues for applications in material science and condensed matter physics.

Abstract:

Pulsars are rapidly spinning and magnetized neutron stars and powerful particle accelerators. How and where exactly the particles are accelerated is a mystery. Gamma-ray observations are a powerful tool to solve this long-standing puzzle. One of the paradigms in pulsar physics I grew up with was that no pulsar should be detectable above 100 GeV. With VERITAS, an array of four imaging atmospheric Chernekov telescopes, we have now detected pulsed emission from the Crab pulsar above 100 GeV, proving that this paradigm is wrong. I present this ground-breaking detection by VERITAS and put it into the context of present theoretical understanding. I close by discussing what this detection could possibly mean for future pulsar observations in the very-high energy gamma-ray band.