This review covers the modern era of experimental kaonic atom studies, encompassing 20
years of activity, defined by breakthroughs in technological developments which allowed …

To test bound-state quantum electrodynamics (BSQED) in the strong-field regime, we have
performed high precision x-ray spectroscopy of the 5 g–4 f and 5 f–4 d transitions (BSQED …

We describe a series of microcalorimeter X-ray spectrometers designed for a broad suite of
measurement applications. The chief advantage of this type of spectrometer is that it can be …

The aim of the hadron physics research programs conducted at J-PARC is to explore the
structure of hadronic matter using the world's highest-intensity meson beams. Since the first …

We observed electronic K x rays emitted from muonic iron atoms using superconducting
transition-edge sensor microcalorimeters. The energy resolution of 5.2 eV in FWHM allowed …

We have measured the 3 d→ 2 p transition x rays of kaonic He 3 and He 4 atoms using
superconducting transition-edge-sensor microcalorimeters with an energy resolution better …

Precision study of few-electron, high-Z ions is a privileged field for probing high-field, bound-
state quantum electrodynamics (BSQED). However, the accuracy of such tests is plagued by …

We present a high energy resolution x-ray spectrometer for the tender x-ray regime (1.6–5.0
keV) that was designed and operated at Stanford Synchrotron Radiation Lightsource. The …

We are develo** a transition edge sensor (TES) microcalorimeter array based on a Ti/Au
superconducting bilayer, as a backup option for the X-IFU instrument on the Athena X-ray …

Code-division multiplexing (CDM) offers a path to reading out large arrays of transition edge
sensor (TES) X-ray microcalorimeters with excellent energy and timing resolution. We …