Brandon Bachler with Dan Akerib and Kathy Kash

Fabrication and Characterization of Superconducting Films for Dark Matter Particle Detectors

The Cryogenic Dark Matter Search (CDMS) experiment uses particle detectors that, when operated at temperatures near 10-20 mK, can measure both an ionization signal and a phonon signal from a particle interaction. The transition-edge sensors used in the phonon detection are made with superconducting films fabricated through the deposition of amorphous Al, W, and Si, followed by various etching, photolithographic, and annealing techniques. Our goal is to explore characterization and testing techniques of the films, as well as to investigate preparation techniques to improve their quality – specifically uniformity and range of T c . Cryogenic measurements and room temperature measurements will be made using a variety of techniques, including x-ray crystallography and surface resistivity measurements.