TY  - JOUR
AU  - Cardoch, Sebastian
AU  - Trost, Fabian
AU  - Scott, Howard
AU  - Chapman, Henry N.
AU  - Caleman, Carl
AU  - Timneanu, Nicusor
TI  - Decreasing ultrafast X-ray pulse durations with saturable absorption and resonant transitions
JO  - Physical review / E
VL  - 107
IS  - 1
SN  - 2470-0045
CY  - Woodbury, NY
PB  - Inst.
M1  - PUBDB-2022-07537
SP  - 015205
PY  - 2023
N1  - ISSN 2470-0053 not unique: **2 hits**.
AB  - Saturable absorption is a nonlinear effect where a material’s ability to absorb light is frustrated due to a high influx of photons and the creation of electron vacancies. Experimentally induced saturable absorption in copper revealed a reduction in the temporal duration of transmitted X-ray laser pulses, but a detailed account of changes in opacity and emergence of resonances is still missing. In this computational work, we employ non-local thermodynamic equilibrium plasma simulations to study the interaction of femtosecond X-rays and copper. Following the onset of frustrated absorption, we find that a K–M resonant transition occurring at highly charged states turns copper opaque again. The changes in absorption generate a transient transparent window responsible for the shortened transmission signal. We also propose using fluorescence induced by the incident beam as an alternative source to achieve shorter X-ray pulses. Intense femtosecond X-rays are valuable to probe the structure and dynamics of biological samples or to reach extreme states of matter. Shortened pulses could be relevant for emerging imaging techniques.
LB  - PUB:(DE-HGF)16
C6  - 36797944
UR  - <Go to ISI:>//WOS:000923229600007
DO  - DOI:10.1103/PhysRevE.107.015205
UR  - https://bib-pubdb1.desy.de/record/490197
ER  -