RF superconductivity

for particle accelerators


USPAS, Summer Session, June 6 - July 1, 2022

Instructors

Sergey Belomestnykh and Sam Posen (Fermilab)

Irina Petrushina (Stony Brook University))

Silvia Verdu Andres (BNL)

Course description

The course will be taught remotely via Zoom. A Zoom meeting link will be provided to registered students by the USPAS office.

The students are expected to have access to a computer equipped with a microphone for interaction with instructors and other students. Having a camera is not required, but encouraged.


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 simulation exercises. Homework problems will be regularly assigned during the course, and a final exam at the end of the course will be given. 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 following textbook provided by USPAS will be extensively used during the course:

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


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:

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)

Additional reference books and online resources:


Credit Requirements

Students will be evaluated based on the following performances: final exam (50%), homework assignments, simulation exercises, and class participation (50%).

Picture gallery

Tentative Schedule

All classes are scheduled for Monday through Friday from 10:00am to 1:00pm CDT

Week 1

June 6 - Lecture 1: Introduction (S. Belomestnykh)

Accelerators and Beams: Tools of discovery and innovation

Lecture 2-3: RF fundamentals, part 1&2 (S. Verdu Andres)

June 7 - Lecture 4: SRF fundamentals, part 1 (S. Belomestnykh)

Lecture 5: SRF fundamentals, part 2 (S. Belomestnykh)

Review session

Homework #1, due on June 9, before lectures

June 8 - Lecture 6-7: Cavity performance frontier, part 1&2 (S. Posen)

June 9 - Lecture 9: SRF system requirements (S. Posen)

Lecture 8: Related phenomena (I. Petrushina)

Review session

June 10 - Computer simulation project - session 1 (I. Petrushina)

Computer simulation project exercises

Review session

Homework #2, due on June 14, before lectures

Week 2

June 13 - Lecture 10: Beam-cavity interaction (S. Verdu Andres)

RF_power_with_beam_loading.pdf

Review of Homework #1

June 14 - Lecture 11: Cavity design (I. Petrushina)

Computer simulation project - session 2 (I. Petrushina)

Pillbox.cst

June 15 - Lecture 12-13: Systems engineering, parts 1&2 (S. Posen)

Review of Homework #2

June 16 - Lecture 14: Cryomodule design (S. Posen)

Lecture 15: Cavity frequency tuners (S. Posen)

Review session

Homework #3, due on June 21, before lectures

June 17 - Computer simulation project - session 3 (S. Verdu Andres)

Week 3

June 20 - Lecture 16: Fundamental power couplers (I. Petrushina)

Lecture 17: HOM dampers (I. Petrushina)

Review session

June 21 - Computer simulation project - session 4 (S. Verdu Andres)

Review session

June 22 - Lecture 18: Case study: Deflecting/crab cavities (S. Verdu Andres)

Review of Homework #3

June 23 - Computer simulation project - session 5 (I. Petrushina / S. Verdu Andres)

Computer simulation project report writing

Homework #4, due on June 28, before lectures

June 24 - Lecture 19: Case study: SRF guns (I. Petrushina)

Review session

Week 4

June 27 - Lecture 20: Cavity fabrication and processing (S. Posen)

Lecture 21: SRF cavity testing and instrumentation (S. Belomestnykh)

Review session

June 28 - Lecture 22: Cavities for low- and medium-beta accelerators (S. Belomestnykh)

Review session

Take home final exam, due on July 1, before lectures

June 29 - Lecture 23: High power RF systems (S. Belomestnykh)

Lecture 24: Case study: LCLS-II (S. Belomestnykh)

Review of Homework #4

June 30 - Lecture 25-26: Cryogenics (guest lecture by A. Klebaner)

Review session

July 1 - Lecture 27: SRF in quantum regime (S. Posen)

Lecture 28: Overview of remaining SRF challenges (S. Belomestnykh)

Q&A session

July 8 - Final grades are sent to USPAS and students

Questions? Send email to

S. Belomestnykh: sbelomes-at-fnal.gov

S. Posen: sposen-at-fnal.gov

I. Petrushina: ipetrushina-at-bnl.gov

S. Verdu Andres: sverdu-at-bnl.gov