Ultrashort Free-Electron Laser X-ray Pulses
AbstractFor the investigation of processes happening on the time scale of the motion of bound electrons, well-controlled X-ray pulses with durations in the few-femtosecond and even sub-femtosecond range are a necessary prerequisite. Novel free-electron lasers sources provide these ultrashort, high-brightness X-ray pulses, but their unique aspects open up concomitant challenges for their characterization on a suitable time scale. In this review paper we describe progress and results of recent work on ultrafast pulse characterization at soft and hard X-ray free-electron lasers. We report on different approaches to laser-assisted time-domain measurements, with specific focus on single-shot characterization of ultrashort X-ray pulses from self-amplified spontaneous emission-based and seeded free-electron lasers. The method relying on the sideband measurement of X-ray electron ionization in the presence of a dressing optical laser field is described first. When the X-ray pulse duration is shorter than half the oscillation period of the streaking field, few-femtosecond characterization becomes feasible via linear streaking spectroscopy. Finally, using terahertz fields alleviates the issue of arrival time jitter between streaking laser and X-ray pulse, but compromises the achievable temporal resolution. Possible solutions to these remaining challenges for single-shot, full time–energy characterization of X-ray free-electron laser pulses are proposed in the outlook at the end of the review. View Full-Text
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Helml, W.; Grguraš, I.; Juranić, P.N.; Düsterer, S.; Mazza, T.; Maier, A.R.; Hartmann, N.; Ilchen, M.; Hartmann, G.; Patthey, L.; Callegari, C.; Costello, J.T.; Meyer, M.; Coffee, R.N.; Cavalieri, A.L.; Kienberger, R. Ultrashort Free-Electron Laser X-ray Pulses. Appl. Sci. 2017, 7, 915.
Helml W, Grguraš I, Juranić PN, Düsterer S, Mazza T, Maier AR, Hartmann N, Ilchen M, Hartmann G, Patthey L, Callegari C, Costello JT, Meyer M, Coffee RN, Cavalieri AL, Kienberger R. Ultrashort Free-Electron Laser X-ray Pulses. Applied Sciences. 2017; 7(9):915.Chicago/Turabian Style
Helml, Wolfram; Grguraš, Ivanka; Juranić, Pavle N.; Düsterer, Stefan; Mazza, Tommaso; Maier, Andreas R.; Hartmann, Nick; Ilchen, Markus; Hartmann, Gregor; Patthey, Luc; Callegari, Carlo; Costello, John T.; Meyer, Michael; Coffee, Ryan N.; Cavalieri, Adrian L.; Kienberger, Reinhard. 2017. "Ultrashort Free-Electron Laser X-ray Pulses." Appl. Sci. 7, no. 9: 915.
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