Characterization and Fabrication of the TES Arrays for the Spider, Keck and BICEP2 CMB Polarimeters

Abstract

Spider, the Keck Array, and BICEP2 are projects to study the polarization of the cosmic microwave background (CMB). All three use large format arrays of antenna-coupled, membrane-isolated, transition edge sensors (TES’s). Although similar, each project requires its own set of device parameters, such as thermal conductance, time constants, and normal state resistances. We have perfected a fabrication process that achieves two primary objectives: (1) high device yields of 95% or greater, and (2) very low spreads in devices parameters. Currently our arrays are taking science data at the South Pole in both the BICEP2 and Keck array telescopes. The focal planes for Spider, a high altitude balloon mission, are on schedule for a 2012 deployment. An overview of fabrication and development is given as well as a snapshot of scientific data.