Abstract
We describe a technique for the generation of a solitary attosecond X-ray pulse in a free electron laser (FEL), via a process of self-amplified spontaneous emission. In this method, electrons experience an energy modulation upon interacting with laser pulses having a duration of a few cycles within single-period wiggler magnets. Two consecutive modulation sections, followed by compression in a dispersive section, are used to obtain a single, sub-femtosecond spike in the electron peak current. This region of the electron beam experiences an enhanced growth rate for FEL amplification. After propagation through a long undulator,this current spike emits a {approx}250 attosecond X-ray pulse whose intensity dominates the X-ray emission from the rest of the electron bunch.
Highlights
The undulators are planar with period 3 cm, and 89% of the free-electron laser (FEL) beam line is filled with undulators, with quadrupoles in the gaps to form a FODO lattice
The closest side peaks to the main current peak produce a smaller but comparable amount of peak power; in terms of total x-ray energy, the contribution from the two side peaks is roughly the same as that from the central peak. In experiments using this radiation, the short width of the individual pulses will tend to be obfuscated by the separation between pulses, which is determined by the 1200 nm period of the modulating laser
We consider the radiation produced by an electron beam which has been modified through interacting with two laser pulses, at 1200 and 1600 nm wavelengths, in two separate single-period undulators
Summary
The wiggler parameter K eB0w=2mc (where w is the wiggler period, B0 is the peak magnetic field, e and m are the electron charge and mass, and c is the speed of light) is adjusted to maximize the amplitude of the energy modulation generated within an electron beam by a laser pulse focused in the center of that wiggler. The energy modulation produced by the second laser pulse alone with A 0:07 mJ, 10 fs, in a wiggler with the same wiggler period but K 85, is similar but with lower amplitude and a longer length scale.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Physical Review Special Topics - Accelerators and Beams
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
