Approved for public release; distribution is unlimited / A three dimensional analysis of the intensity distribution of backward optical transition radiation has been performed. The effects of variations in electron energy and beam divergence and on material properties such as dielectric permittivities and the resultant coherence length upon the angular distribution and polarization of optical transition radiation has been investigated. A surprising observation important to the use of optical transition radiation as a diagnostic tool for high energy electron beams is the behavior of the perpendicular component of the intensity. In contrast to low energies where the parallel component dominates, at electron energies above 200 MeV, the perpendicular component dominates. This requires the use of a polarization filter to diagnose particle beam properties at high energies. / http://archive.org/details/threedimensional00long / Lieutenant, United States Navy

In laser wakefield acceleration, an ultra-short high-intensity laser pulse excites a plasma wave, which can sustain accelerating electric fields of several hundred GV/m. This scheme advances a novel concept for compact and less expensive electron accelerators, which can be hosted in a typical university size laboratory. Furthermore, laser wakefield accelerators (LWFA) feature unique electron bunch characteristics, namely micrometer size with duration ranging from several fs to tens of fs. Precise knowledge of the longitudinal profile of such ultra-short electron bunches is essential for the design of future table-top X-ray light-sources and remains a big challenge due to the resolution limit of existing diagnostic techniques. Spectral measurement of broadband coherent and incoherent transition radiation (TR) produced when electron bunches passing through a metal foil is a promising way to analyze longitudinal characteristics of these bunches. Due to the limited reproducibility of the electron source this measurement highly requires single-shot capability. An ultra-broadband spectrometer combines the TR spectrum in UV/NIR (200-1000 nm), NIR (0.9-1.7 µm) and mid-IR (1.6-12 µm). A high spectral sensitivity, dynamic bandwidth and spectral resolution are realized by three optimized dispersion and detection systems integrated into a single-shot spectrometer. A complete characterization and calibration of the spectrometer have been done concerning wavelengths, relative spectral sensitivities, and absolute photometric sensitivities, also taking into account for the light polarization. The TR spectrometer is able to characterize electron bunches with charges as low as 1pC and can resolve time-scales of 0.4 fs. Electron bunches up to 16 fs (rms width) can be reconstructed from their TR spectrum. In the presented work, the self-truncated ionization induced injection (STII) scheme has been explored to study the relevant beam parameters especially its longitudinal bunch profile and the resulting peak current.