2025.04.04

The Plasma Quantum Process Unit holds seminars to disseminate the research activities of the Unit. This time, Prof. Endre Takacs, Clemson University, USA, will give a lecture titled “State-of-the-art x-ray microcalorimeter for studying QED effects in highly charged ions”. We hope many of you will join us.

【Date】 Thursday, April 10, 2025, 14:00-15:00

【Place】Seminar Room (Room 501), 5th floor, Research I Building, National Institute for Fusion Science

【Zoom】 Zoom information will be provided in a separate e-mail

【Lecturer】Prof. Endre Takacs (Department of Physics and Astronomy, Clemson University, USA)

【Title】State-of-the-art x-ray microcalorimeter for studying QED effects in highly charged ions

【Abstract】

Quantum electrodynamics (QED) is one of the most accurate theories of fundamental interactions, and its extraordinary precision provides unique opportunities for scientific discovery, such as the search for new physics. Consequently, stringent experimental tests of QED remain of high importance. Highly charged ions serve as an exceptional test bed due to their enhanced QED effects.
　A Transition-Edge Sensor (TES) x-ray microcalorimeter array was recently commissioned at the Electron Beam Ion Trap (EBIT) at the National Institute of Standards and Technology (NIST) to study these effects. Over the past few decades, the NIST EBIT has produced numerous studies on highly charged ions across diverse fields such as atomic physics, plasma spectroscopy, and laboratory astrophysics. The x-ray microcalorimeter combines high x-ray collection efficiency with excellent resolving power, utilizing 192 individual pixels optimized for x-ray energies ranging from roughly 500 eV to 10,000 eV, achieving an energy resolution of 3.7 eV–5.0 eV over this range.
　Recent measurements that leverage the capabilities of this state-of-the-art instrument will be reported. These include precise (to the ppm level) measurements of forbidden transitions in F-like ions, the observation of ladder ionization from Ni-like metastable levels, and the detection of prominent Ne-like transitions in heavy elements.

【Contact】Hiroyuki Sakaue (sakaue.hiroyuki (at) nifs.ac.jp)