U.S. Particle Accelerator School

CW & High Brightness Electron Sources course

Sponsoring University:

University of Wisconsin - Madison


CW & High Brightness Electron Sources


James Rosenzweig, UCLA and Massimo Ferrario, INFN-LNF, Frascati

The creation of intense, low emittance — high brightness — electron beams is a key enabling technology that makes possible many of today's most compelling, cutting-edge beam applications, such as free-electron lasers, and wake-field accelerators. The devices that are used to create these beams, rf photo injectors and related pulse compressors, have intricate technical and physical aspects. These characteristics range from ultra-high field radio-frequency accelerating cavities and picosecond lasers on the technical side, to the qualitative change of the beam physics to completed domination of collective field over thermal effects. In this course we will introduce the analytical methods needed to understand the relevant physical effects, notably, as longitudinal dynamics in violently accelerating systems, single component plasma-like transverse beam behavior, and radiative effects in magnetic-bunching systems. As proper control over these physical effects requires correct implementation of the technical systems, we will then discuss the design of rf cavity, laser and magnetic components of electron sources. The practical use of computer codes that illustrate standard design and simulation problems will be reviewed. Advanced problems from the field, such as asymmetric emittance beams for linear colliders, magnetic and velocity bunching, and high brightness CW superconducting rf photo injectors will be employed to illuminate the interplay of physics and technology in modern electron sources. Prerequisites: junior-level electricity and magnetism; classical dynamics.