Progress towards cavity-based X-ray free-electron lasers : demonstration of cavity ringdown and microbunch rotation out-coupling

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Current X-ray Free-Electron Lasers (XFELs), including the Linac Coherent Light Source (LCLS) at SLAC, are single-pass SASE (self-amplified spontaneous emission) machines, where electrons produce X-rays as they pass through an undulator line just once. The exponential gain of X-ray power in an XFEL occurs as X-rays act on the electron beam, causing it to form microbunches at the X-ray wavelength. In a SASE XFEL, the X-rays which initiate this process come from noise in the beam, and thus X-rays produced by current XFELs are transversely coherent, but longitudinally noisy. In proposed cavity-based XFELs (CBXFELs), by contrast, X-rays are spectrally filtered and returned by mirrors from the end of the undulator line to the beginning, so a strong X-ray pulse is used to seed the FEL process on subsequent passes. Future X-ray light sources based on CBXFELs can thus improve longitudinal coherence and spectral brightness, and promise to be more stable than current XFELs. In this thesis I discuss the requirements to build a CBXFEL cavity and several aspects of CBXFEL development. I cover in detail the characterization of CBXFEL-quality diamond mirrors, two cavity out-coupling methods including active cavity Q-switching and microbunch rotation, and a demonstration of a 14 m Bragg-reflecting cavity.


Type of resource text
Form electronic resource; remote; computer; online resource
Extent 1 online resource.
Place California
Place [Stanford, California]
Publisher [Stanford University]
Copyright date 2024; ©2024
Publication date 2024; 2024
Issuance monographic
Language English


Author Margraf, Rachel A
Degree supervisor Huang, Zhirong, 1968-
Thesis advisor Huang, Zhirong, 1968-
Thesis advisor Marinelli, Agostino
Thesis advisor Reis, David A, 1970-
Degree committee member Marinelli, Agostino
Degree committee member Reis, David A, 1970-
Associated with Stanford University, School of Humanities and Sciences
Associated with Stanford University, Department of Applied Physics


Genre Theses
Genre Text

Bibliographic information

Statement of responsibility Rachel Margraf-O'Neal.
Note Submitted to the Department of Applied Physics.
Thesis Thesis Ph.D. Stanford University 2024.

Access conditions

© 2024 by Rachel A Margraf
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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