Berlin 2012 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 41: Focused Session: Cryogenic Detectors

TT 41.1: Hauptvortrag

Donnerstag, 29. März 2012, 15:00–15:30, H 2053

Performance and Understanding of Transition-Edge Sensor Microcalorimeters — •Simon Bandler — NASA/Goddard Space Flight Center, Greenbelt, MD, USA — University of Maryland College Park, College Park, MD, USA

Microcalorimeters and bolometers incorporating Transition-Edge Sensor (TES) thermometers are achieving record-setting performance for a wide range of measurements ranging from microwave power to MeV-scale particles. TES thermometers consist of superconducting thin films electrically biased in the resistive transition. In this presentation I will describe recent results from a variety of different microcalorimeters designed for X-ray spectroscopic measurements in astrophysics and solar physics. These devices combine excellent energy sensitivity and high efficiency, can be fabricated in large numbers using lithographic techniques, and can be read out in large numbers using SQUID amplifiers. Despite the record-setting performance and growing utilization of the technology, a theoretical model of the physics governing TES devices' superconducting phase transition has until recently proven elusive. Our group at NASA has shown that TESs exhibit weak-link behavior, where, unlike previous models, the average strength of the order parameter varies over the TES. We find our TES measurements have a natural explanation in terms of a spatially varying order parameter. Implications of weak link behavior for microcalorimeter array design, performance and read-out are discussed.