Boston University
Introduction to Synchrotron Radiation and Free Electron Lasers
Kwang-Je Kim, ANL and Zhirong Huang, SLAC
Purpose and Audience
This course is an introduction to the physics of high-brightness radiation beams, the performance of which have been increased remarkably recently by use of insertion devices in synchrotron radiation facilities and by the development of free electron laser (FEL) oscillators and high-gain amplifiers. Specifically, the course is designed toward students and scientists who are interested in the physics and technology of high brightness electron beams as drivers for the production of x-ray photons in the form of synchrotron radiation and FELs.
Prerequisites
Classical Mechanics and Electromagnetism.
Objectives
The goal of this course is to explore how electromagnetic radiation is generated in a magnetic device (an undulator) and how the beam-radiation interaction leads to light amplification. Upon completion of the course, the students are expected to understand the fundamental FEL physics and be able to design and evaluate the performance of a FEL system.
Instructional Method
The course consists of lectures in both morning (3 hrs. per class day), and afternoon sessions (minimum of 2 hrs. per class day). In addition, afternoon exercise sessions are planned to assign and explain homework each day.
Course Content
The course begins with a review on fundamental concepts in beams, brightness, and coherence. The second part introduces basic properties of synchrotron radiation by relativistic electron beams in magnetic devices and the enhanced brightness of partially coherent radiation from periodic magnetic devices known as undulators. The third part considers how the electromagnetic field generated by the electrons in undulators influence the electron motion leading to amplified radiation. Free
electron laser oscillators utilize such amplification to generate fully coherent radiation in the visible and the infrared wavelength regions where the oscillator mirrors are available. The fourth part studies principles of high-gain free electron lasers in which the gain in single pass is made to be extremely high by use of high-brightness electron beams and long undulators. High-gain FELs are important as next generation radiation devices in x-ray region since optical cavity is not necessary and the initial noise signals are amplified to intense coherent radiation known as the self-amplified spontaneous radiation (SASE). After a discussion of basic concepts, a more rigorous treatment of high-gain FELs including SASE will be given based on Maxwell-Vlasov equations. FEL simulation techniques and seeding/enhancement schemes are also explored. Time permitting, we will also discuss FELs in quantum regime and Smith-Purcell FELs as a backward wave oscillator.
Reading Requirements
Instructors will provide lecture notes.
Credit Requirements
Students will be evaluated based on homework assignments (80%) and classroom participation (20%).