U.S. Particle Accelerator School

Beam Experiments and Measurements at the NSCL course

Sponsoring University:

Michigan State University


Beam Experiments and Measurements at the NSCL


Marc Doleans, Guillaume Machicoane, Walter Hartung and NSCL staff, Michigan State University, and Eduard Pozdeyev, Brookhaven National Laboratory

Purpose and Audience
The purpose of this course is to provide an introduction and an overview to the physics and technology of particle accelerators. This course is appropriate for last year physics undergraduate students, graduate students or students from other fields with particular interest in accelerator physics and technology. The course is also intended to broaden the background of engineers and technicians working in fields related to accelerator technology. This course is an introduction to the experimental techniques involved in the measurement of beam and accelerator properties. It is a combination of lectures to provide the theory and background for the measurements, followed by actual execution of the measurements on an operating machine, as well as separate component systems. 

Courses in College Physics, first year Calculus, and the USPAS course "Accelerator Fundamentals" or equivalent.

On completion of this course, students are expected to understand the basic physical principles that make accelerators function, together with the design principles of various engineering components of accelerators such as magnets, accelerator control systems, beam monitoring instrumentation, beam-based measurement techniques, and radio frequency (rf) cavities. Measurements will be motivated and supported by accelerator theory, and model-based calculations.

Instructional Method
Work on the coupled cyclotron ion source facility begins with safety systems, an introduction to control systems, and the instrumentation and software that is used to manipulate the heavy ion beams and to make beam measurements. During the course of this week, each group of students will perform 4-5 machine experiments and then complete analysis of the measured data. NSCL accelerator staff will act in a supporting role, to offer suggestions and guidance, and to answer questions. Students will first spend time in planning or analysis, and then in making measurements using the systems making up the NSCL facility. Work on the small ion ring will follow the same procedures as above. The work with the superconducting rf structures will be a subset of the following topics: accelerating mode measurements; RF coupler measurements; cavity tuning; higher-order mode measurements; microphonic excitation measurements; RF controls and feedback. Measurements will be done at low power on cavities at room temperature. No beams will be available for the superconducting cavity studies.

Course Content
The week involves three aspects for which students will be split up into teams of 5 each. Part of the time will be spent taking measurements and operating the small ion ring at NSCL to observe space charge effects in circulating ion beams. The second part will be spent taking measurements, analyzing data and covering some theoretical work associated with superconducting niobium rf structures at NSCL. Some of this study might involve half wave cavities, elliptical cavities and/or prototype systems. The third part will be spent taking measurements and operating the ECR ion sources for NSCL to observe source tuning, beam transport and related emittance growth mechanisms.

Reading Requirements
(to be provided by the USPAS) “Handbook of Accelerator Physics and Engineering”, by Alexander W. Chao and Maury Tigner, World Scientific, 3rd print (2006).

Credit Requirements
Students will be evaluated based on performance at the Laboratory. Instructors and staff will be actively involved with each group of students during the course of each day and each activity. A review of plans and analysis, and the measurement of appropriate parameters will constitute 50% of the final grade. Performance associated with operations and organization of how to make appropriate measurements will constitute 50% of the final grade.