U.S. Particle Accelerator School

Experimental Beam Physics course

Sponsoring University:

Duke University


Experimental Beam Physics
Duke PHY745 Section 3, "Experimental Beam Physics"


Ying K. Wu, Stepan F. Mikhailov, Hao Hao, Duke University

Purpose and Audience
The purpose of the course is to instruct the students on essential instrumentation and diagnostics, measurement techniques, and setup and tuning procedures used at the light source storage ring. The course is intended to be mainly hands-on work with electron and photon beams, and with tools used for beam measurement and manipulation. 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.

USPAS graduate course "Accelerator Physics" or equivalent experience.

It is the responsibility of the student to ensure that he or she meets the course prerequisites or has equivalent experience.

The objectives of the course are:
1) to become familiar with beam instrumentation and diagnostics, and as well as measurement techniques at the light source storage ring;
2) to learn about the fundamental physics principles for operation of various beam instrumentation and diagnostics systems;
3) to learn about the controls and data acquisition software for beam measurements;
4) to learn the most important steps to set up an electron storage ring;
5) to participate in tuning a storage ring FEL and Compton gamma-ray source;
6) to evaluate beam measurement data.

Instructional Method
This course will focus on a set of hands-on beam monitoring and measurement experiments at the Duke electron storage ring, the storage ring FEL, and High Intensity Gamma-ray Source (HIGS). During the morning session a lecture 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 on that day. This is followed by a session for the students to develop a plan and software program for the measurement of the day, either individually or in small groups. During the afternoon session (or evening session, depending on availability of the accelerator beam time), the students will carry out their measurements individually or in groups. For the first week, students will learn about various beam measurement systems and techniques, again either individually or in small groups, by performing beam experiments in a monitoring mode while the storage ring and related light sources are in the routine user mode of operation. For the second week, the students of the course will be divided into two groups to participate in the beam measurements and studies, exercising a full control of the operation and tuning of the storage ring and related light sources. The plan is to carry out a total of eight to ten experiments (3 hours of beam time per experiment). The students can sign up for four to five experiments, without having to stay with a fixed group. When the first group is performing the measurement, the second group will be working on the data analysis and preparation of the lab reports.

One of the goals of the course is to allow the students to become familiar with the instrument and diagnostics used for beam measurements. The students will learn about the instrumentation for measuring beam current, beam orbit, transverse beam size, bunch length, and synchrotron and betatron tunes. The students will later use these basic measurement techniques to develop more sophisticated experiments which will be carried out in the second week. 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 also participate in the setup, tuning, and optimization of the storage ring FEL and HIGS Compton light source. For homework, students will write the lab reports to document the measurement procedures, observations made during the experiment, and results of the data evaluation and analysis.

Course Content
Beam monitoring experiments

1. Electron beam orbit stability monitoring (BPM system)
2. Beam lifetime measurement (DCCT system)
3. Transverse beam size measurement and monitoring (synchrotron radiation port)
4. Bunch length measurement and monitoring (dissector system)
5. Synchrotron tune monitoring
6. Betatron tune monitoring
7. Integrated beam monitoring
8. Injection efficiency measurement and monitoring

Beam tuning and measurements

1. Storage ring injection tuning and study of injection efficiency
2. Measuring response matrices (s-matrices) of the storage ring optics
3. Control and tuning of a local bump
4. Beam based alignment for quadrupoles
5. Closed orbit correction
6. Beam parameter measurements: synchrotron and betatron tunes, chromaticity, and eta functions
7. Measuring the bunch length as a function of beam current (microwave instability study)
8. Storage ring FEL setup, tuning, and optimization
9. Compton gamma-ray beam production, tuning, and optimization
10. Tuning and operation of longitudinal bunch-by-bunch feedback system

Reading Requirements
The course will follow on-line technical notes and other publications made available by the instructors.

Credit Requirements
Students will be evaluated based on their participation and contributions during the beam measurements and tuning (50%) and their lab reports (50%).

IU/USPAS course: Physics 571