The fundamental coherent radiation emission processes from a bunched charged particles
beam are outlined. In contrast to spontaneous emission of radiation from a random electron …

The brightness of x-ray sources has been increased one to ten billion times by x-ray free-
electron lasers (XFELs) that generate high intensity coherent photon pulses at wavelengths …

Advances in FEL technologies have contributed remarkably to various scientific fields over
the past decade, and ultrafast molecular dynamics is no exception. The ability to probe …

We present an x-ray regenerative amplifier free-electron laser design capable of producing
fully coherent hard x-ray pulses across a broad tuning range at a high steady state repetition …

Recent studies of the performance of radio-frequency (rf) copper cavities operated at
cryogenic temperatures have shown a dramatic increase in the maximum achievable …

We report the generation of ultrahigh brightness X-ray pulses using the Fresh Bunch Self-
Seeding (FBSS) method in an X-ray Free Electron Laser (XFEL). The FBSS method uses …

We demonstrate a novel multistage amplification scheme for self-amplified spontaneous-
emission free electron lasers for the production of few femtosecond pulses with very high …

The feasibility of generating X-ray pulses in the 4–8 keV fundamental photon energy range
with 0.65 TW peak power, 15 fs pulse duration and 9× 10− 5 bandwidth using the LCLS-II …

We present results of an experiment where, using a 200 GW CO 2 laser seed, a 65 MeV
electron beam was decelerated down to 35 MeV in a 54-cm-long strongly tapered helical …

Development of superconducting undulators (SCUs) continues at the Advanced Photon
Source (APS). Several planar SCUs were designed and built, and two of them are currently …