U.S. Particle Accelerator School

RF Cavity and Component Design for Accelerators course

Sponsoring University:

Boston University


RF Cavity and Component Design for Accelerators


Alireza Nassiri and Geoff Waldschmidt, Argonne National Laboratory

Purpose and Audience
The purpose of this course is to introduce the students to the design and modeling of an rf cavity and component for accelerators. This course is designed and suitable for senior undergraduate and/or first year graduate students from fields of physics, applied physics or electrical engineering who are considering pursuing accelerator physics and engineering as a possible career. This course provides essential background and hands-on rf and microwave modeling and simulations for accelerator design. This course will be limited to twenty students.

College Physics, introductory course in electromagnetism and first-year calculus.

The objectives of this course are: 1) to review fundamental rf and microwave engineering principles using mathematical treatment, 2) apply these principles to design and analyze rf cavities and components for accelerators applications, 3) learn and become profession in using numerical simulation and modeling packages and 4) use these tools to design and analyze realistic rf components for accelerators. The students will also be exposed to some basic beam cavity interaction. On the completion of this course, students are expected to understand fundamental rf and microwave principles and be able to successfully design, model and analyze accelerator components using numerical codes.

Instructional Method
This course combines lectures and computer laboratory to accomplish its objectives. This includes a series of 20 lectures during morning sessions, followed by afternoon computer laboratory sessions. The purpose of the lectures is to teach students fundamental concepts through mathematical treatment and to apply learned principles to numerical deign and modeling. The instructors will help students to get familiar with various software packages and how to use them effectively. This will be accomplished through interactive and hands-on activities. Ample examples will be provided to help students to develop their computer skills. For the computer laboratory sessions, students initially work in small groups and as they gain experience and expertise, they will work on their own. Students are expected to complete a set of laboratory assignments in additional to problem sets from the morning lectures. Students are expected to choose and complete a final design project assignment.

Course Content
We will review the basic rf and microwave theory and properties, transmission lines, Smith chart, impedance matching, field analysis of transmission lines, waveguides, accelerating cavities, power couplers and other resonance structures. Computer laboratory sessions will focus on understanding and using design and simulation codes: HFSS, Microwave Studio and MAFIA. Other topics will include: Maxwell’s equations, Green’s functions, boundary conditions, wave propagation and plane waves, plane wave reflection from a media interface, dielectric interface. Transmission line theory; including wave propagation, field analysis, generator and load mismatches, Smith chart, rectangular and circular waveguides, coaxial lines, microwave network analysis, impedance matching, microwave resonators, physics of the microwave tubes, dielectric and other lossy materials, time harmonic analysis, perturbation and variational techniques, microwave antennas, and microwave measurements; attenuation, SWR, impedance, phase-shift, noise factor. Acceleration by rf systems for the linear accelerator and storage rings including beam and cavity interaction, beam-loading, higher -order mode (HOM) effects and mode damping, deflecting cavity. Numerical methods, including finite difference time domain, finite element, stability conditions, and absorbing boundary conditions will be discussed.

Reading Requirements
(to be provided by the USPAS) "Microwave Engineering," Wiley (1998), second edition by David M. Pozar. Additional suggested reading reference: R.E. Collin,” Foundation of Microwave Engineering,” McGraw-Hill 1994. Additional reading materials will be provided.

Credit Requirements
Students will be evaluated based on performance: final exam (30% of final grade), computer lab assignments (35% of final grade), and homework assignments (35% of final grade).