{"id":247010,"date":"2026-11-10T06:47:56","date_gmt":"2026-11-10T12:47:56","guid":{"rendered":"https:\/\/lifeboat.com\/blog\/2026\/11\/light-pulse-pairs-reveal-the-femtosecond-decay-of-an-inner-shell-hole-in-xenon-atoms"},"modified":"2026-11-10T06:47:56","modified_gmt":"2026-11-10T12:47:56","slug":"light-pulse-pairs-reveal-the-femtosecond-decay-of-an-inner-shell-hole-in-xenon-atoms","status":"publish","type":"post","link":"https:\/\/lifeboat.com\/blog\/2026\/11\/light-pulse-pairs-reveal-the-femtosecond-decay-of-an-inner-shell-hole-in-xenon-atoms","title":{"rendered":"Light-pulse pairs reveal the femtosecond decay of an inner-shell hole in xenon atoms"},"content":{"rendered":"\n<p>Researchers at the UVSOR Synchrotron Facility (Institute for Molecular Science, Japan) and partner institutions have observed the decay of a xenon 4D core hole, an inner-shell vacancy, directly in the time domain. They used pairs of phase-coherent extreme ultraviolet pulses from a synchrotron to make the photoelectron wave packets they released interfere. The contrast of the interference fringes decreased over a few femtoseconds as the delay between the pulses increased. A model using literature core-hole lifetimes of about 6 femtoseconds reproduced this rapid decay of the fringe contrast. The study is <a href=\"https:\/\/link.aps.org\/doi\/10.1103\/bz6n-x687\" target=\"_blank\">published<\/a> in the journal Physical Review A.<\/p>\n<p>Auger decay is an ultrafast process. A valence electron fills an inner-shell vacancy, and another electron is ejected. It dominates the decay of the xenon 4D hole. Until the mid-2000s, experiments mostly inferred such dynamics from the spectral widths of photoelectron lines. Attosecond streaking later made time-domain observation possible. While attosecond streaking has been widely employed for time-domain observations of Auger processes, the research team has introduced an alternative approach based on coherent pulse pairs. The present work extends the photoelectron wave-packet interferometry to core holes created by photoionization.<\/p>\n<p>At beamline BL1U of the UVSOR-III synchrotron, two undulators in tandem, separated by a phase-shifter magnet, emitted phase-coherent pulse pairs. The photon energy was 93.4 eV, with a bandwidth of about 3%. The phase-shifter magnet set the delay between pulses with attosecond resolution. The pulses ionized xenon 4D electrons, and a hemispherical analyzer recorded photoelectron spectra as a function of delay. Helium, which has no comparable decay, served as a reference. Its fringe contrast revealed the instrument\u2019s own contrast loss.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Researchers at the UVSOR Synchrotron Facility (Institute for Molecular Science, Japan) and partner institutions have observed the decay of a xenon 4D core hole, an inner-shell vacancy, directly in the time domain. They used pairs of phase-coherent extreme ultraviolet pulses from a synchrotron to make the photoelectron wave packets they released interfere. The contrast of [\u2026]<\/p>\n","protected":false},"author":427,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[48],"tags":[],"class_list":["post-247010","post","type-post","status-publish","format-standard","hentry","category-particle-physics"],"_links":{"self":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/247010","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/users\/427"}],"replies":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/comments?post=247010"}],"version-history":[{"count":0,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/247010\/revisions"}],"wp:attachment":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/media?parent=247010"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/categories?post=247010"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/tags?post=247010"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}