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arXiv · 2009.10914

Coherent X-rays with Tunable Time-Dependent Polarization

Nicholas Sudar·Ryan Coffee·Erik Hemsing
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Abstract

We describe a method for producing high power, coherent x-ray pulses from a free electron laser with femtosecond scale periodic temporal modulation of the polarization vector. This approach relies on the generation of a temporal intensity modulation after self seeding either by modulating the seed intensity or the beam current. After generating a coherent temporally modulated $s$-polarization pulse, the electron beam is delayed by half a modulation period and sent into a short orthogonally oriented undulator, serving as a $p$-polarization afterburner. We provide simulations of three configurations for realizing this polarization switching, namely, enhanced self seeding with an intensity modulation generated by 2 color self seeding, enhanced self seeding of a current modulated bunch, and regular self seeding of a current modulated bunch. Start to end simulations for the Linac Coherent Light Source-II are provided for the latter.

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Nicholas Sudar, Ryan Coffee, Erik Hemsing. 2020-09-23. Coherent X-rays with Tunable Time-Dependent Polarization. https://doi.org/10.1103/physrevaccelbeams.23.120701

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