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Superconducting Polarimeter Arrays

Abstract: A new class of observatories are currently poised to dramatically improve our understanding of the early universe. At the heart of these observatories are large scale polarimeter arrays read out with ultra sensitive superconducting power meters. The realization of these arrays requires a careful balance of microwave design, low temperature physics, and micro-fabrication. I will discuss how we navigated these challenges with experiments designed to investigate improvements in dielectric loss, Tc uniformity, engineered heat capacity, and structural stability of delicate membranes. These improvements were applied to the development of two separate polarimeter instruments one at the South Pole Telescope and the other at the Atacama Cosmology Telescope with different performance requirements and design parameters including transition edge sensor material, bath temperature, readout scheme, and on-sky power loading. I will also describe our progress in developing lumped-element microwave kinetic inductance polarimeters for the study of star formation in cold Galactic interstellar clouds at Terahertz frequencies for the next generation Balloon-borne Large-Aperture Submillimeter Telescope.
Speaker: Dale Li - NIST Boulder
Speaker Bio: Dale has been a contributing member of the quantum devices group at NIST in Boulder, Colorado since 2007. Before working on quantum sensors, he was awarded a National Research Council postdoctoral research associateship to work on quantum information with superconducting phase qubits and mechanical resonators. He earned his Ph.D. in physics at Yale in 2007 studying quantum decoherence in dipolar solids with NMR under Sean Barrett. Daleís bachelorís degree in physics and applied math at UC Berkeley included a senior honors thesis on neutral pion reconstruction for the BaBar experiment at SLAC.
Poster Link: Poster