An optical storage cavity-based, Compton-backscatter X-ray source using the MKV free electron laser

Date
2012-12
Authors
Hadmack, Michael Robert
Contributor
Advisor
Department
Instructor
Depositor
Speaker
Researcher
Consultant
Interviewer
Annotator
Journal Title
Journal ISSN
Volume Title
Publisher
[Honolulu] : [University of Hawaii at Manoa], [December 2012]
Volume
Number/Issue
Starting Page
Ending Page
Alternative Title
Abstract
A compact, high-brightness x-ray source is presently under development at the University of Hawaiʻi Free Electron Laser Laboratory. This source utilizes Compton backscattering of an infrared laser from a relativistic electron beam to produce a narrow beam of monochromatic x-rays. The scattering efficiency is greatly increased by tightly focusing the two beams at an interaction point within a near-concentric optical storage cavity, designed with high finesse to coherently stack the incident laser pulses and greatly enhance the number of photons available for scattering with the electron beam. This dissertation describes the effort and progress to integrate and characterize the most important and challenging aspects of the design of this system. A low-power, near-concentric, visible-light storage cavity has been constructed as a tool for the exploration of the performance, alignment procedures, and diagnostics required for the operation of a high power infrared storage cavity. The use of off-axis reflective focussing elements is essential to the design of the optical storage cavity, but requires exquisite alignment to minimize astigmatism and other optical aberrations. Experiments using a stabilized HeNe laser have revealed important performance characteristics, and allowed the development of critical alignment and calibration procedures, which can be directly applied to the high power infrared storage cavity. Integration of the optical and electron beams is similarly challenging. A scanning-wire beam proffiler has been constructed and tested, which allows for high resolution measurement of the size and position of the laser and electron beams at the interaction point. This apparatus has demonstrated that the electron and laser beams can be co-aligned with a precision of less than 10 μm, as required to maximize the x-ray production rate. Equally important is the stabilization of the phase of the GHz repetition rate electron pulses arriving at the interaction point and driving the FEL. A feed-forward amplitude and phase compensation system has been built and demonstrated to substantially improve the uniformity of the electron bunch phase, thus enhancing both the laser performance and the beam stability required for efficient x-ray production. Results of all of these eefforts are presented, together with a summary of future work.
Description
Ph.D. University of Hawaii at Manoa 2012.
Includes bibliographical references.
Keywords
X-ray, MKV free electron laser
Citation
Extent
Format
Geographic Location
Time Period
Related To
Theses for the degree of Doctor of Philosophy (University of Hawaii at Manoa). Physics.
Table of Contents
Rights
Rights Holder
Local Contexts
Collections
Email libraryada-l@lists.hawaii.edu if you need this content in ADA-compliant format.