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PHYSICS PHD DISSERTATION DEFENSE: James MacArthur

Ph.D. Candidate: James MacArthur

Research Advisor: Zhirong Huang

Date: Monday August 5, 2019
Time: 9:30 am
Location: SLAC, Kavli building (51), 3rd floor conference room (305)

Title: Electron Beam Manipulations at the Angstrom Level and Attosecond Timescale for X-ray FELs

Abstract: X-ray Free-Electron Lasers (FELs) have now operated for a decade, delivering linearly polarized pulses with durations down to a few femtoseconds to users. I will discuss two projects that manipulate the FEL gain medium -- a relativistic electron beam -- in order to broaden the capabilities of the Linac Coherent Light Source (LCLS). The first is the production of isolated, circularly polarized x-ray pulses with the help of a helical undulator and non-intuitive electron microbunch rotation. The microbunch rotation required for isolating circular pulses is also useful for multiplexing LCLS and for outcoupling radiation from an x-ray oscillator. The second project is the production of sub-femtosecond x-ray pulses with a tailored electron beam phase space. We tailor the transverse phase space of the electron beam core with coherent radiation from the electron beam tail produced in a magnetic wiggler. The resultant x-ray pulses contain six orders of magnitude more energy than comparable sub-femtosecond sources.

August 5, 2019 - 9:30am
SLAC, Kavli building (51), 3rd floor conference room (305