Opacity effects in a solid-density aluminium plasma created by photo-excitation with an X-ray laser

The intensities within the focal spots of the output of recently developed X-ray sources based on free-electron-laser (FEL) technology are so great that atoms within the focal region can potentially absorb several photons during the few tens of femtosecond X-ray pulse. Furthermore, the duration of t...

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Bibliographic Details
Main Authors: Rackstraw, D, Vinko, S, Ciricosta, O, Cho, B, Engelhorn, K, Chung, H, Brown, C, Burian, T, Chalupsky, J, Falcone, R, Graves, C, Hajkova, V, Higginbotham, A, Juha, L, Krzywinski, J, Lee, H, Messerschmidt, M, Murphy, C, Ping, Y, Scherz, A, Schlotter, W, Toleikis, S, Turner, J, Vysin, L, Wang, T
Format: Journal article
Published: 2014
Description
Summary:The intensities within the focal spots of the output of recently developed X-ray sources based on free-electron-laser (FEL) technology are so great that atoms within the focal region can potentially absorb several photons during the few tens of femtosecond X-ray pulse. Furthermore, the duration of the FEL X-ray pulse is comparable to the Auger decay times of inner-shell holes created by the X-rays themselves. We report here how such a scenario can lead to opacity broadening of the fluorescence radiation emitted by the hot, dense plasma, which is created as a result of the X-radiation focussed onto a solid target, and in particular present calculations of the broadening of the Kα emission in a solid-density aluminium target, produced when the FEL photon energy is tuned below the Al K-edge, but is resonant with the Kα transition. © 2014 Elsevier B.V.