Free-Electron Lasers: Status and Applications

Abstract

A free-electron laser consists of an electron beam propagating through a periodic magnetic field. Today such lasers are used for research in materials science, chemical technology, biophysical science, medical applications, surface studies, and solid-state physics. Free-electron lasers with higher average power and shorter wavelengths are under development. Future applications range from industrial processing of materials to light sources for soft and hard x-rays.

Synchrotron ultrafast techniques for photoactive transition metal complexes

“…The availability in the near future of hard X-ray FEL facilities [220][221][222][223][224][225][226][227][228][229] will represent an impressive improvement in the potentialities of both TR-XSS and TR-XAS techniques, both in terms of photon flux (moving from 10 6 to 10 12 photons per electron bunch) and ultimate time resolution (the typical bunch width moving from 10 −10 down to 10 −14 s). The development of adequate measurement techniques and data-acquisition schemes for measuring X-ray scattering/absorption data at FELs will be essential to derive full benefit from these new-generation photon sources.…”

“…However, for the time being, this apparently simple solution is not feasible since, for q > 7 Å −1 , the experimental q I(q) data are dominated by noise and the interval 4 Å −1 < q < 7 Å −1 is too limited for extracting any reliable structural information. This situation will change in the future, with the availability of hard X-ray free electron lasers (FELs) [220][221][222][223][224][225][226][227][228][229], where the number of photons per electron pulse will reach values as high as 10 12 , compared with 10 6 for third-generation synchrotron radiation sources.…”

Laboratory infrared spectroscopy of PAHs

“…Novel birefringent materials allowed non-linear frequency down-conversion methods to penetrate further into the IR (Bosenberg & Guyer 1993). Moreover, tunable infrared free electron lasers (O'Shea & Freund 2001), where radiation is generated by a relativistic beam of electrons injected into a periodic magnetic field structure (wiggler), entered the realm of spectroscopy.…”

Nonlinear photoionization in the soft X-ray regime

“…Based on Higher-Harmonics Generation (HHG) or Free-Electron Laser (FEL) technique, the strong Xray pulses with femtosecond pulse duration will allow in the near future to study ultra-fast processes, e.g., on surfaces or within biological systems [4][5][6]. However, photon-matter interaction at ultra-high intensities is affected by non-linear processes as known from optical radiation [7,8].…”