Cryogenic microcalorimeters are outstanding tools for X-ray spectroscopy due to their unique combination of excellent energy resolution and close to 100% detection efficiency. While well-established microcalorimeter concepts have already proven impressive performance, their energy resolution has yet to improve to be competitive with cutting-edge wavelength-dispersive grating or crystal spectrometers. We hence present an innovative SQUID-based superconducting microcalorimeter with an in-situ tunable gain as alternative concept that is based on the strong temperature dependence of the magnetic penetration depth of a superconductor operated close to its critical temperature. Measurements using a prototype device show no sign for any hysteresis effects that often spoil the performance of superconducting microcalorimeters. Moreover, our predictions of the achievable energy resolution show that a competitive energy resolution O(300meV) with a suitable combination of absorber and sensor material should be easily possible.
@article{arxiv.2310.03489,
title = {SQUID-based superconducting microcalorimeter with in-situ tunable gain},
author = {Constantin Schuster and Sebastian Kempf},
journal= {arXiv preprint arXiv:2310.03489},
year = {2023}
}
Comments
This manuscript has been submitted to the AIP journal "Applied Physics Letters", 6 pages, 5 figures