RF superconductivity

for particle accelerators

USPAS, Winter Session, January 27 - February 7, 2025

Instructors

Sergey Belomestnykh and Vijay Chouhan (Fermilab)

Silvia Verdu Andres and Paolo Berrutti (BNL)

Course description

Purpose and Audience

This graduate-level course covers the science fundamentals and practical engineering, manufacturing, processing, and operational aspects of the superconducting RF (SRF) cavities and systems – the state-of-the-art technology used for both pulsed and continuous wave particle acceleration. The course is intended to give a comprehensive introduction to the field for students, engineers, and physicists interested in entering this field, as well as to deepen understanding of the technology for those already exposed to some aspects of SRF science and technology.

Prerequisites:

Basic knowledge of electromagnetism, microwave techniques, solid state/condensed matter physics, and mathematical methods for scientists and engineers at the senior undergraduate level.

It is the responsibility of the student to ensure that they meet the course prerequisites or have equivalent experience.

Objectives

Upon completion of the course students are expected to have a clear understanding of the advantages, basic underlying physics, open questions, and domain of applicability of SRF technology, as well as state-of-the-art infrastructure and techniques required for successful implementation of SRF-based accelerators.

Instruction Method

The course will include lectures, review sessions, and computer simulation exercises. Four homework assignments, each containing from 2 to 4 problems, will be given. The final exam problems will encompass the topics learned during the course. Instructors and/or teaching assistants will be available for help during evening homework sessions.

Course Content

The course lectures will start from an introduction to the principles of RF acceleration and a general mathematical description of microwave cavities. The phenomenon of superconductivity, and the advantages it brings for RF cavities will then be discussed in detail. In-depth coverage of principles of RF superconductivity and various types of SRF cavities used for different applications will follow. Extrinsic phenomena adversely affecting the performance will be discussed. Modern cavity manufacturing, processing, and basic measurement techniques will then be reviewed. Key steps and challenges in engineering and operating of complete SRF cryomodules (cryostats, cavities, input couplers, higher order mode couplers and loads, frequency tuners) will be fully discussed. Beam-cavity interaction issues in operation will also be presented. Overview of the recent scientific progress and outlook with of remaining challenges and promising research directions will conclude the course.

Textbook

The textbook RF Superconductivity for Accelerators, by H. Padamsee, J. Knobloch, and T. Hays, John Wiley & Sons, 2nd edition (2008), will be extensively used during the course. Several copies will be available at USPAS for students to share.

Other Reading Recommendations

It is recommended that students refresh their knowledge of the fundamentals of electrodynamics at the level of one of the following (or other similar) textbooks:

Fields and Waves in Communication Electronics (Chapters 1 through 11) by S. Ramo, J. R. Whinnery, and T. Van Duzer, John Wiley & Sons, 3rd edition (1994)
Classical Electrodynamics (Chapters 1 through 8) by J. D. Jackson, John Wiley & Sons, 3rd edition (1999)
Foundations for Microwave Engineering (Chapters 1 through 8) by R. E. Collins, John Wiley & Sons (2001)

and their knowledge of condensed matter physics/superconductivity at the level of:

Solid State Physics (Chapter 34 - Superconductivity) by N. W. Ashcroft and N. D. Mermin, Cengage Learning (1976)
Introduction to superconductivity: second edition (Chapters 1-2) by M. Tinkham, Dover Books on Physics (2004)

Books and online resources for further reading:

Handbook of Accelerator Physics and Engineering, edited by A. W. Chao, M. Tigner, H. Weise, and F. Zimmermann, World Scientific, 3rd Edition (2023)
RF Superconductivity: Science, Technology, and Applications, by H. Padamsee, Wiley-VCH (2009)
Superconducting Radiofrequency Technology for Accelerators: State of the Art and Emerging Trends, by H. Padamsee, Wiley-VCH (2023)

The Physics of Electron Storage Rings: An Introduction, by M. Sands
Microwave Theory and Applications, by S. F. Adam
High Energy Electron Linacs: Applications to Storage Ring RF Systems and Linear Colliders, by Perry B. Wilson
Microwave Engineering (Chapters 2 through 6), by David M. Pozar, Wiley, 3rd Edition (2005).
Electromagnetic Waves and Antennas (Chapers 9 through 11, 13 and 14), by Sophocles J. Orfanidis, online (2016)

Credit Requirements

Students will be evaluated based on the following performances: final exam (40% of final grade), homework assignments (including computer simulation report) and class participation (60% of final grade).

USPAS Computer Requirements

There will be no Computer Lab and all participants are required to bring their own portable computer to access online course notes and computer resources. This can be a laptop or a tablet with a sufficiently large screen and keyboard. Windows, Mac, and Linux-based systems that are wifi capable and have a standard web browser and mouse are all acceptable. You should have privileges for software installs. If you are unable to bring a computer, please contact uspas@fnal.gov ASAP to request a laptop loan. Very limited IT support and spare loaner laptops will be available during the session.