International award for pioneering x-ray spectroscopy with superconducting transition-edge sensor microcalorimeters

This award presentation was primarily based on the team’s pioneering measurements of exotic atom x-ray emission with a TES microcalorimeter spectrometer.  These demonstration measurements were performed on pionic helium and carbon and conducted at one of the high-energy beamlines at Paul Scherer Institute. The results [1] were recently acknowledged as a “Highlight of the Year” at RIKEN [2] for “the world’s first application of a TES spectrometer for hadronic-atom x-ray spectroscopy and a key milestone toward more general use of high-resolution microcalorimeter spectrometers at charged-particle beam lines.” Previous measurements of similar exotic atoms using conventional semiconductor x-ray spectrometers had insufficient resolution to detect small spectral shifts due to strong-force interactions. By utilizing the microcalorimeter spectrometer, the team was able to achieve energy resolution that is over two orders of magnitude better than previous measurements with conventional spectrometers. Based on the success of these initial results, the PML Group recently deployed a dedicated spectrometer to the Japan Proton Accelerator Research Complex (J-PARC), where it will perform follow-on measurements of exotic atoms later this year.

[1] Tatsuno et. al., “Absolute Energy Calibration of X-ray TESs with 0.04 eV Uncertainty at 6.4 keV in a Hadron-Beam Environment”, JLTP, p1—8, 2016.

[2] http://www.rarf.riken.jp/researcher/APR/APR048/pdf/12.pdf