News Article

Advances in Cryogenic Radiation Detectors (September 7, 2023). Cryogenic radiation detectors are attractive because of their extremely high energy resolution, typically on the order of eV for X-rays in the keV range. One of their applications is in astrophysics. Recently, the Japan Aerospace Exploration Agency (JAXA) launched the XRISM (X-Ray Imaging and Spectroscopy Mission) satellite in collaboration with NASA and ESA (for more details, see Daniel Clery, “Revolutionary x-ray sensor to probe workings of black holes and supernovae”, Science, 381, 720–721 (2023). https://doi.org/10.1126/science.adk3474). The X-ray telescope is equipped with a high-energy resolution microcalorimeter detector called Resolve, which is expected to reveal more details about exploding stars, the matter orbiting supermassive black holes, and the merging of galaxy clusters. The detectors appear to be useful not only in such astrophysics, but also in X-ray spectrometry. One of the most important research projects is the precise determination of the fundamental X-ray parameters for many L lines in the soft X-ray region. The research team at NIST in Boulder, Colorado, USA has published a number of papers since 2017 (see, for example, J. W. Fowler et al., “A reassessment of the absolute energies of the x-ray L lines of lanthanide metals”, Metrologia 54, 494 (2017). https://doi.org/10.1088/1681-7575/aa722f, “Absolute energies and emission line shapes of the L x-ray transitions of lanthanide metals”, Metrologia 58, 015016 (2021). https://doi.org/10.1088/1681-7575/abd28a, “Energy Calibration of Nonlinear Microcalorimeters with Uncertainty Estimates from Gaussian Process Regression”, Journal of Low Temperature Physics 209, 1047–1054 (2022). https://doi.org/10.1007/s10909-022-02740-w, “The potential of microcalorimeter X-ray spectrometers for measurement of relative fluorescence-line intensities”, Radiation Physics and Chemistry, 202, 110,487 (2023). https://doi.org/10.1016/j.radphyschem.2022.110487). For more information on recent advances in cryogenic radiation detectors and their applications, see some review articles such as J. Ullom and D. Bennett, “Review of superconducting transition-edge sensors for x-ray and gamma-ray spectroscopy”, Superconducting Science and Technology, 28, 084003 (2015). https://doi.org/10.1088/0953-2048/28/8/084003 and M. Ohkubo, “Advances in superconductor quantum and thermal detectors for analytical instruments”, Journal of Applied Physics. 134, 081101 (2023). https://doi.org/10.1063/5.0151581