The Primordial Anisotropy Polarization Pathfinder Array (PAPPA): Instrument Overview and Status

摘要

PAPPA is a balloon-based experiment designed to measure the polarization of the Cosmic Microwave Background using candidate technology for an eventual Einstein Inflation Probe mission. It will survey a 20° x 20° patch of sky with 0.5° angular resolution covering 3 passbands centered at 89, 212 and 302 GHz. Detection will be accomplished via antenna-coupled transition edge sensors (TESs) with SQUID-based readouts. In the eventual flight package, band denning filters and MEMS-based polarization modulators will be incorporated into the superconducting microstrip transmission lines that terminate in resistors that are thermally coupled to the TESs. The MEMS switches will allow on-chip polarization modulation that is faster than significant detector gain variations. The initial configuration will incorporate a simplified focal plane augmented by quasioptical polarization modulation. We describe the overall instrument design and present a summary of the current progress.