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DTSTAMP:20260711T104557Z
SUMMARY:Attosecond ionization dynamics:  from perturbative to strong field.
DESCRIPTION:Speaker\nProfessor Alexandra Landsman\nThe Ohio State Universit
 y\nAbstract:\nRecent advances in X‑ray free‑electron laser (XFEL) tech
 nology have opened new opportunities to probe photoionization dynamics on 
 attosecond timescales and to access strong‑field regimes at X‑ray wave
 lengths that were previously experimentally inaccessible. In this talk\, I
  will discuss two complementary classes of XFEL experiments that together 
 illuminate the timing and mechanisms of electron emission in atoms and mol
 ecules.  First\, I will address attosecond photoemission delays measure
 d using circular streaking techniques\, with a focus on extending ionizati
 on‑delay chronoscopy from linearly to circularly polarized probes.  I
  will also address the challenges of interpreting streaking delays at low 
 photoelectron energies.  Second\, I will present recent theoretical work 
 exploring a new non‑perturbative strong‑field X‑ray regime\, where 
 multiphoton above‑threshold ionization (ATI) is driven by attosecond XFE
 L pulses. In helium\, this regime produces distinct angular and spectral s
 ignatures that are clearly separated from perturbative harmonic contributi
 ons.  Together\, these studies demonstrate how XFELs enable both quantit
 ative attosecond chronoscopy and fundamental tests of strong‑field ion
 ization physics at short wavelengths\, establishing a foundation for futu
 re experiments in atoms and molecules.\n Alexandra Landsman\nProfessor of
  Physics\nThe Ohio State University\nDepartment of Physics\nPhysics Resear
 ch Building\n191 W Woodruff Ave\, Columbus\, OH 43210\n 
URL:https://www.imperial.ac.uk/events/211480/attosecond-ionization-dynamics
 -from-perturbative-to-strong-field/
DTSTART;TZID=Europe/London:20260724T120000
DTEND;TZID=Europe/London:20260724T130000
LOCATION:B630\, Blackett Building\, South Kensington Campus\, Imperial Coll
 ege London\, London\, SW7 2AZ\, United Kingdom
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