Berlin 2018 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 103: Superconductivity: Cryogenic Particle Detectors

TT 103.3: Vortrag

Donnerstag, 15. März 2018, 18:00–18:15, H 2053

Microwave SQUID multiplexing of metallic magnetic calorimeters — •M. Wegner, D. Richter, F. Ahrens, L. Gastaldo, A. Fleischmann, S. Kempf, and C. Enss — Kirchhoff-Institute for Physics, Heidelberg University, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany.

The most promising readout technique for large arrays of metallic magnetic calorimeters (MMCs) is microwave SQUID multiplexing (µMUXing), in particular since MMCs require a large bandwidth per channel. Each channel of a µMUX consists of a non-hysteretic rf-SQUID which is inductively coupled to a superconducting microwave λ/4 resonator. Due to the mutual inductance between SQUID and resonator and the flux dependence of the SQUID inductance, a signal in the MMC is transduced into a resonance frequency shift which can be detected by continuously monitoring the resonator transmission. By coupling many readout channels, each having a unique resonance frequency, to a common feedline, this technique allows for a simultaneous readout of hundreds of detectors.

In this contribution we present a full characterization of our state-of-the-art µMUX having 32 readout channels. By providing sufficient bandwidth per channel, we are able to resolve the fast intrinsic signal rise time of MMCs. The measured energy resolution is Δ E_FWHM = 11 eV. Based on the results of our comprehensive device characterization, we developed and fabricated a next-generation multiplexer chip. We will discuss our latest multiplexer design and will show our most recent experimental results.