Dresden 2014 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 7: Superconductivity: Cryodetectors

TT 7.6: Vortrag

Montag, 31. März 2014, 10:45–11:00, HSZ 03

Solid state physics and engineering to push resolving power of magnetic calorimeters beyond 10000 — •Daniel Hengstler, Anna Ferring, Lisa Gamer, Jeshua Geist, Mathäus Krantz, Andreas Pabinger, Christian Pies, Christian Schötz, Sebastian Kempf, Loredana Gastaldo, Andreas Fleischmann, and Christian Enss — Kirchhoff-Institut für Physik, Universität Heidelberg, INF 227, 69120 Heidelberg

Metallic magnetic calorimeters are energy dispersive particle detectors, operated at temperatures below 50 mK that make use of a paramagnetic temperature sensor to convert the energy deposited by an absorbed particle into a magnetic flux change in a SQUID, which can be read-out as a voltage signal with low noise and large bandwidth. During the last decade we've been optimizing the signal size of MMCs by numerical optimizations and the consequent use of micro-fabrication techniques, while lowering the readout noise close to quantum limit. The combination of both rewarded us recently with an instrumental linewidth of 1.6 eV (FWHM) for 6 keV x-rays, which on the one hand is a world record, on the other hand is much less than expected from the signal-to-noise-ratio in those measurements. Such discrepancies can easily arise from instabilities of the total gain, or --- more interestingly --- from a-thermal phonon loss or position dependencies.

In this talk we summerize the physics of MMCs, highlighting the presently done homework in solid state physics and engineering to reach resolving powers beyond 10000, and show recent results of MMCs in various applications.