# 18th International Workshop on Low Temperature Detectors (LTD-18)

22-26 July 2019
Milano
Europe/Rome timezone

## maXs: Metallic Magnetic Calorimeter Arrays for High Resolution X-Ray Spectroscopy

24 Jul 2019, 12:45
15m
Auditorium G. Testori (Milano)

### Auditorium G. Testori

#### Milano

Piazza Città di Lombardia, 1, 20124 Milano MI
Oral Presentation Low Temperature Detector Development and Physics

### Speaker

Daniel Hengstler (KIP, Heidelberg University)

### Description

The high dynamic range as well as the very good linearity in combination with an excellent energy resolution make metallic magnetic calorimeters (MMCs) ideal detectors for different applications in high-resolution X-ray spectroscopy. The maXs detector family consists of several 1- and 2-dimensional MMC arrays based on paramagnetic temperature sensors made of Ag:Er or Au:Er that are optimized for X-ray energies up to $20$, $30$ and $200\,{\rm keV}$, respectively.
We report latest results of the two-dimensional maXs-30 detector array which features 8x8 pixels with an active detection area of $4{\rm x}4\,{\rm mm}^2$. The detector achieved an energy resolution of $9.8\,{\rm eV}$ at $60\,{\rm keV}$, corresponding to an excellent resolving power above $6000$. The non-linearity of the detector is as small as $1\,\%$ at $60\,{\rm keV}$ and allows for an absolute energy determination of line energies with only a few calibration lines. A sub-${\rm eV}$ precision on line energies up to $60\,{\rm keV}$ was achived. We discuss the homogeneity over the 64-pixel array and show that the uniform behaviour allows easy co-adding of the individual spectra of different pixels even over several months of measurement time.
Due to this performance, the maXs detector arrays are currently used in a number of experiments, ranging from the spectroscopy of highly charged ions at storage rings or EBITs in atomic physics to the successful investigation of the nuclear isomer state of $^{229}{\rm Th}$. Furthermore, these detectors are promising candidates to be used in the upcoming IAXO experiment for the search of solar axions.

Less than 5 years of experience since completion of Ph.D Y N

### Primary authors

Daniel Hengstler (KIP, Heidelberg University) Christian Schötz (KIP, Heidelberg University) Steffen Allgeier (KIP, Heidelberg University) Marvin Friedrich (KIP, Heidelberg University) Sebastian Kempf (Kirchhoff Institute for Physics, Heidelberg University) Loredana Gastaldo (Kirchhoff Institute for Physics, Heidelberg University) Andreas Fleischmann (Heidelberg University) Christian Enss (Kirchhoff Institute for Physics, Heidelberg University)