U.S. Particle Accelerator School
U.S. Particle Accelerator School
Education in Beam Physics and Accelerator Technology

Beam Measurements and Diagnostics on an Electron Storage Ring


Texas A&M University Public Partnership & Outreach

Course Name:

Beam Measurements and Diagnostics on an Electron Storage Ring


Ying K. Wu and Jun Yan, Duke University; Hao Hao, Oak Ridge National Lab

Purpose and Audience
The purpose of this course is to introduce the students to essential instrumentation and diagnostics, measurement techniques, and setup and tuning procedures used in accelerator physics research, commissioning, and operation of light source storage rings. The course is intended to be mainly hands-on work using online software to monitor, measure, and control electron and photon beams in the storage ring at the High Intensity Gamma-ray Source (HIGS) facility, Triangle Universities Nuclear Laboratory. The course is appropriate for graduate students with a strong background in accelerator physics, as well as for postdocs, physicists, and engineers working in the field.

Courses in classical mechanics, electrodynamics, and physical or engineering mathematics, all at entrance graduate level; and the USPAS course ‘Fundamentals of Accelerator Physics & Technology,’ or equivalent are required. USPAS graduate course "Accelerator Physics" or equivalent experience and experience with software data analysis using tools such as Matlab are strongly recommended.

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

The objectives of the course are:
1) Become familiar with beam instrumentation, diagnostics, and measurement techniques at the storage ring;
2) Learn about the fundamental physics principles for beam instrumentation and diagnostic systems;
3) Learn about the controls and data acquisition software for beam measurements;
4) Evaluate and analyze beam measurement data; and
5) Participate in tuning a storage ring and a storage-ring based free-electron laser (FEL).

Instructional Method
This course will focus on a set of beam monitoring and measurement experiments at the Duke University electron storage ring and storage ring FEL using already developed online controls and measurement software. The emphasis is not on software development but the use of applications in making measurements and tuning the accelerators. Short lectures will be given to introduce essential physics concepts, operational principles and techniques, and related hardware equipment and software tools used for the measurements to be conducted. In follow-on sessions, the students will work individually or in small groups to develop a plan and high-level software for the measurements that they will carry out when the accelerators are available. The students will develop hands-on experimental skills by working with the accelerators and beam measurement systems. The students will perform beam studies in a monitoring mode while the storage ring and related light sources are in the routine user mode of operation; and for some studies, the students will be divided into groups to participate in the beam manipulation and measurements, exercising full control of the operation and tuning of the storage ring. A set of planned experiments are listed below. All measurements using beam monitoring will be carried out simultaneously by all students. However, only one group can carry out a beam tuning or manipulation measurement at a time, during which the other students will be working on the data analysis and lab report.

One of the goals of the course is to allow the students to become familiar with the diagnostic instruments used for beam measurements at a light source storage ring. The students will learn about instrumentation for measuring beam current, beam orbit, transverse beam size, bunch length, and synchrotron and betatron tunes. They will use these basic measurement techniques to develop more sophisticated experiments. The students will also learn about the basic operation steps to set up a light source storage ring and carry out beam injection and basic tuning of the storage ring. They will participate in the setup, tuning, and optimization of a storage ring FEL.For homework, students will first analyze the measurement data, and then write lab reports to document the measurement procedures, describe the observations made during the experiment, and present results using figures and tables.

Course Content
Beam monitoring and beam tuning experiments

  1. Electron beam orbit stability monitoring (the beam position monitor or BPM system);
  2. Beam lifetime measurement (using a DCCT);
  3. Transverse beam size measurement (a beam profile measurement system using synchrotron radiation);
  4. Bunch length measurement (using a dissector);
  5. Synchrotron tune measurement (using a beam pickup);
  6. Measurement of eta functions (using BPMs);
  7. Measurement of betatron tunes and chromaticity (the tune measurement system); and
  8. Measurement of response matrices (s-matrices) of the storage ring optics and closed orbit correction.

Storage ring and FEL operation demonstration:

  1. Storage ring injection tuning and study of injection efficiency; and
  2. Storage ring FEL setup, tuning, and optimization.

Reading Requirement
The course will follow online technical notes and other publications made available by the instructors.

A supplemental text, Minty and Zimmermann, “Measurement and Control of Charged Particle Beams,” Springer 2003, will be provided by the USPAS. This text is also available for free via Open Access https://www.springer.com/gp/book/9783540441878

Credit Requirements
Students will be evaluated based on their participation and contributions during the beam measurements and tuning (40%), their lab reports (40%), and a concept quiz (20%).

Indiana University course number: Physics 671, "Advanced Topics in Accelerator Physics"
Michigan State University course number: PHY 963, "U.S. Particle Accelerator School"
MIT course number: 8.790, "Accelerator Physics"