Speaker
Description
High intensity, sub-femtosecond XFEL pulses are key to taking full advantage of nonlinear x-ray spectroscopies and advanced imaging methods. The X-ray Laser-Enhanced Attosecond Pulses (XLEAP) collaboration is an ongoing project for the development of attosecond x-ray modes at the Linac Coherent Light Source (LCLS). Here we report development of a high power attosecond mode via cascaded amplification in two undulator stages. In the first stage, a sub-femtosecond x-ray pulse is produced by enhanced self-amplified spontaneous emission (ESASE) by a femtosecond, high-current spike within the electron beam. A magnetic chicane delays the electron beam, allowing the x-ray pulse to slip onto a fresh slice of the bunch in the second undulator stage, where it undergoes further amplification. We experimentally demonstrate generation of sub-femtosecond duration soft x-ray free electron laser pulses with hundreds of microjoules of energy, and use angular streaking to characterize the pulse durations.
This work was supported by US Department of Energy Contracts No. DE-AC02-76SF00515
