Investigation of the coherent synchrotron radiation spectrum as a probe of charge dynamics

Abstract

Coherent synchrotron, Cherenkov and transition radiation have generated and measured in the far infrared spectral region. This work represents the first identification and separation of the Cherenkov and transition radiation components with transition radiation producing the strongest signal. High-intensity picosecond pulses of radiation are observed for all three sources. The angular dependence in the mm wave region is not the same as that given by high-frequency radiation expressions since the wavelength and the beam radiator size are comparable; hence diffraction effects are important. A prototype polarizing Michelson interferometer has been designed, constructed and is now being tested. The diffraction-limited design meets the demands of the rigorous space and experimental conditions in the linac area. The instrument is of rugged constructed using retroreflectors and thus is optically stable for long periods of time. It contains both reference and interferogram detectors to minimize the influence of linac drifts on the data analysis. To eliminate the intensity loss at low frequencies due to diffraction and waveguide effects the next generation of interferometer and detector will have 2x larger apertures.