Theory of Microwave Instability and Coherent Synchrotron Radiation in Electron Storage Rings
Bursting of coherent synchrotron radiation has been observed and in fact used to generate THz radiation in many electron storage rings. In order to understand and control the bursting, we return to the study of the microwave instability. In this paper, we will report on the theoretical understanding, including recent developments, of the microwave instability in electron storage rings. The historical progress of the theories will be surveyed, starting from the dispersion relation of coasting beams, to the work of Sacherer on a bunched beam, and ending with the Oide and Yokoya method of discretization. This theoretical survey will be supplemented with key experimental results over the years. Finally, we will describe the recent theoretical development of utilizing the Laguerre polynomials in the presence of potential-well distortion. This self-consistent method will be applied to study the microwave instability driven the impedances due to the coherent synchrotron radiation. Over the past quarter century, there has been steady progress toward smaller transverse emittances in electron storage rings used for synchrotron light sources, from tens of nm decades ago to the nm range recently. In contrast, there is not much progress made in the longitudinal plane. For an electron bunch in a typical ring, its relative energy spread {sigma}{sub {delta}} remains about 10{sup -3} and its length {sigma}{sub z} is still in between 5 mm to 10 mm. Now the longitudinal emittance ({sigma}{sub {delta}}{sigma}{sub z}) becomes a factor of thousand larger than those in the transverse dimensions. In this paper, we will address questions of: How short a bunch can be? What is the fundamental limit? If there is a limit, is there any mitigation method? Since the synchrotron radiation is so fundamental in electron storage rings, let us start with the coherent synchrotron radiation (CSR).
- Research Organization:
- SLAC National Accelerator Lab., Menlo Park, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- AC02-76SF00515
- OSTI ID:
- 1032769
- Report Number(s):
- SLAC-PUB-14561; TRN: US1200561
- Journal Information:
- Conf.Proc.C110904:3775-3779,2011, Conference: Invited paper, 2nd International Particle Accelerator Conference (IPAC-2011), San Sebastian, Spain, 4-9 Sep 2011
- Country of Publication:
- United States
- Language:
- English
Similar Records
Optimizing ring-based CSR sources
Investigation of Microbunching Instabilities in Modern Recirculating Accelerators