ATLAS

Abstract:

We present first significant limits on WIMP dark matter by the phonon-light technique, where combined phonon and light signals from a scintillating cryogenic detector are used to suppress the non-nuclear recoil background. The performance of the detectors developed for the second phase of the CRESST experiment will be discussed and data collected with two prototype modules in a short run, corresponding to a net exposure of 20.5 kg days, will be presented. (c) 2005 Elsevier B.V. All rights reserved.

Abstract:

We have developed multichannel SQUID systems for two particle physics experiments: a 66-channel system for detector readout in the CRESST dark matter search, and a 12-channel magnetometry system for the CryoEDM neutron electric dipole moment experiment. These different applications have different requirements, for example in the CRESST system it is important to minimise crosstalk, while the CryoEDM system must be shielded from magnetic noise. Future experiments such as the EURECA dark matter project may require systems with a much higher number of channels. (c) 2006 Elsevier B.V. All rights reserved.

Abstract:

The plasmon excitations of the degenerate free-electron gas in the surface space-charge region of InSb have been studied using high-resolution electron-energy-loss spectroscopy. Semiclassical dielectric theory simulations of the energy-loss spectra have been performed using the hydrodynamic and Boltzmann-Mermin models. While both analyses include the effects of temperature, conduction band nonparabolicity, spatial dispersion and collisional damping, the hydrodynamic model is not able to quantitatively reproduce the experimental spectra at higher excitation wave vectors. The measured spectral shapes are only accurately reproduced when collisionless plasmon damping is included explicitly using the Boltzmann-Mermin dielectric function. © 2006 The American Physical Society.