SKM 2023 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 57: Poster: Superconductivity I

TT 57.26: Poster

Donnerstag, 30. März 2023, 15:00–18:00, P2/OG2

Towards large-area 256-pixel MMC arrays for high resolution X-ray spectroscopy — •Andreas Abeln, Steffen Allgeier, Axel Brunold, Lars Eisenmann, Daniel Hengstler, Lukas Münch, Alexander Orlow, Andreas Fleischmann, and Christian Enss — Kirchhoff-Institute for Physics, Heidelberg University

Metallic Magnetic Calorimeters (MMCs) are energy-dispersive cryogenic particle detectors. Operated temperatures below 50 mK, they provide very good energy resolution, high quantum efficiency as well as linearity over a large energy range. In many precision experiments on X-ray spectroscopy the photon flux is small, thus a large active detection area is desirable. Therefore, we develop arrays with increasing number of pixels. For a cost-effective read-out of a growing number of detector channels we investigate different multiplexing techniques.

In this contribution we present the design of a novel 16×16 pixel MMC array. The pixels provide a total active area of 4 mm×4 mm and are equipped with 5 µm thick absorbers made of gold. This ensures a stopping power of at least 50 % for photon energies up to 20 keV. The expected energy resolution is ΔE=1.4 eV (FWHM) at an operating temperature of 20 mK. We give an overview about the microfabrication process and focus on the challenging task of producing through wafer vias to heat sink the MMC pixels to the wafer backside. These vias are realized by holes etched through the silicon substrate and subsequently lined with gold to achieve high thermal coupling between detector pixels and the cryostat.