U.S. Particle Accelerator School

Ion Injectors for Accelerators course

Sponsoring University:

College of William and Mary


Ion Injectors for Accelerators


Martin Stockli, ORNL

This course is designed to give an introduction to the physics and technology of ion injectors. Ion injectors use an ion source that produces the desired ions, which then are extracted to form an ion beam. The ion flux describes the intensity of the ion beam while its emittance describes its focusability. The low-energy beam transport system shapes the beam for proper injection into an RFQ or a LINAC. Pulsing and chopping can be used to achieve the desired time structure of the ion beam. The course starts with an introduction to low-pressure discharges and to vacuum to understand the basic limitations of ion sources. Ion sources for positive-, negative-, and highly-charged ions are discussed in more details. Some plasma physics is presented to understand the ion extraction process. Beam current and emittance measurements and analysis are discussed in detail. Transport properties of ion optical elements are discussed to understand the transport and shaping of the ion beam. Ion beam modulations through ion source pulsing and/or electric choppers are discussed. Prerequisites: College physics and first-year calculus highly desirable. Familiarity with computers is useful, but not mandatory. Textbook to be provided: "Ion Sources” by Huashun Zhang (Science Press-Springer, 1999).