RF Superconductivity for Particle Accelerators

Instructors:

Sergey Belomestnykh and Alexander Romanenko

Fermi National Accelerator Laboratory


Two-week course at USPAS 2017, Lisle, IL

June 12-23, 2017

Purpose and Audience

The two-week course will cover the science fundamentals and practical manufacturing, processing, and operational aspects of the superconducting RF cavities – the state-of-the-art technology used for both pulsed and CW 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.

Prerequisites

Basic knowledge of electromagnetism, microwave techniques, and solid state/condensed matter physics at an undergraduate level.

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.

Instructional Method

The course will include lectures, computer lab, practical laboratory demonstrations, and instructional lab exercises performed at the extensive Fermilab SRF infrastructure. Homework problems will be assigned during the course, and a final exam at the end of the course will be given.

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 including multipacting, field emission, hydrogen Q-disease. 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 reviewed. Overview of the recent scientific progress and future outlook with standing challenges and promising research directions will conclude the course. Several practical exercises and demonstration for key topics will be integrated in the course. The practical exercises will utilize world-class SRF facilities at Fermilab.

Reading Requirements and Suggestions

The following textbook provided by USPAS will be extensively used during the course:

H. Padamsee, J. Knobloch, and T. Hays, RF Superconductivity for Accelerators, John Wiley and Sons, 2nd edition (2008)


It is recommended that students refresh their knowledge of the fundamentals of electrodynamics at the level of one of the following textbooks:

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

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

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

Additional suggested reference books:

    • Handbook of Accelerator Physics and Engineering, edited by A. W. Chao, K. H. Mess, M. Tigner and F. Zimmermann, World Scientific, 2nd Edition (2013)
    • H. Padamsee, RF Superconductivity: Science, Technology, and Applications, Wiley-VCH (2009).

Reference materials on wakefileds, wake potentials and beam loading:

Credit Requirements

Students will be evaluated based on the following performances: final exam (40%), homework assignments and class participation (35%) and lab exercises (25%).

Computer Lab and Codes

During the Computer Lab sessions students will be working on a project using computer codes ABCI and SUPERFISH. The codes will be installed on the USPAS computers. The other codes that will be available on the USPAS computers are: MATLAB, Microsoft Office.

Please keep in mind that commercial software (MATLAB, Microsoft Office) will not be available for installation on students' laptops due to licensing issues. Students will have to use USPAS computers to have access to these software packages if they do not have it. However, it will be sufficient to use LibreOffice or Google Docs instead.

Computer Lab Project

Lecture Notes and Homework Problems

Course schedule

Monday, June 12

Monday 1 homework problems with solutions

Tuesday, June 13

Derivation of the RF power formula for a beam loaded cavity can be found in RF_power_with_beam_loading.pdf

Tuesday 1 homework problems with solutions

Wednesday, June 14

Wednesday 1 homework problems with solutions

Thursday, June 15

Friday, June 16

Hands-on experience day at Fermilab

      • RF measurements (M. Hassan and P. Berrutti)
      • Vertical cavity testing (A. Melnychuk and M. Checchin)

Notes for VTS hands-on experience at Fermilab

Friday 1 homework problems with solution

Monday, June 19

Tuesday, June 20

Tuesday 2 homework problems with solution

Wednesday, June 21

Hands-on experience day at Fermilab

      • Materials science (Y. Trenikhina and Z. Sung)
      • Clean room and chemical facilities (D. Bice, A. Rowe and C. Crawford)

Thursday, June 22

Take home exam problems with solutions

Friday, June 23