June 2019
Original paper by Dr. Motoyama, Dr. Iwasaki, et al. was published in Appl. Phys. Lett. and the press release was issued

A paper by Hiroto Motoyama, Atsushi Iwasaki, et al. by the title, "Broadband nano-focusing of high-order harmonics in the soft X-ray region with ellipsoidal mirror," was published in Applied Physics Letters and a press release of the research was issued from School of Science on June 18, 2019.

Press release: https://www.s.u-tokyo.ac.jp/ja/press/2019/6430/
(Japanese only)