| タイトル | Superconducting Effects in Optimization of Magnetic Penetration Thermometers for X-ray Microcalorimeters |
| 本文（外部サイト） | http://hdl.handle.net/2060/20130013407 |
| 著者（英） | Sadleir, J. E.; Nagler, Peter C.; Stevenson, Thomas R.; Kelly, Daniel P.; Bandler, Simon E.; Balvin, M. A.; Busch, Sarah E.; Merrell, W.; Seidel, George E.; Denis, K. L.; Smith, Stephen J.; Porst, J.-P.; Hsieh, W.-T. |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 2012-10-08 |
| 言語 | eng |
| 内容記述 | We have made high resolution x-ray microcalorimeters using superconducting MoAu bilayers and Nb meander coils. The temperature sensor is a Magnetic Penetration Thermometer (MPT). Operation is similar to metallic magnetic calorimeters, but instead of the magnetic susceptibility of a paramagnetic alloy, we use the diamagnetic response of the superconducting MoAu to sense temperature changes in an x-ray absorber. Flux-temperature responsivtty can be large for small sensor heat capacity, with enough dynamic range for applications. We find models of observed flux-temperature curves require several effects to explain flux penetration or expulsion in the microscopic devices. The superconductor is non-local, with large coherence length and weak pinning of flux. At lowest temperatures, behavior is dominated by screening currents that vary as a result of the temperature dependence of the magnetic penetration depth, modified by the effect of the nonuniformity of the applied field occurring on a scale comparable to the coherence length. In the temperature regime where responslvity is greatest, spadal variations in the order parameter become important: both local variations as flux enters/leaves the film and an intermediate state is formed, and globally as changing stability of the electrical circuit creates a Meissner transition and flux is expelled/penetrates to minimize free energy. |
| NASA分類 | Electronics and Electrical Engineering |
| レポートNO | GSFC.CP.7552.2013 |
| 権利 | Copyright, Distribution as joint owner in the copyright |
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