Konstantin Lekomtsev from the University of London will be discussing:

Coherent Diffraction Radiation as a tool for non-invasive bunch length diagnostics.

Abstract: In this seminar I will discuss Coherent Diffraction Radiation (CDR) phenomenon as a tool for longitudinal beam diagnostics. Precise knowledge of a longitudinal bunch profile is particularly important in the context of the luminosity challenge in the future linear colliders and therefore the development of a non-invasive and robust longitudinal beam diagnostic technique is very important.
CDR is emitted when a bunch of charged particles moves in the vicinity of an optical obstacle (for example a screen, or a slit between screens) and the wavelength of the radiation is larger or comparable to the bunch length. CDR has been experimentally investigated over the period of the last 20 years and has been proven to be very promising candidate for longitudinal diagnostics, due to its non-invasive nature and high radiation intensity.
During the course of the seminar I will discuss a novel two-target scheme for the CDR generation. The experimental demonstration of this scheme is a setup installed at the CLIC Test Facility (CTF3) at CERN. A new theoretical model which was developed specifically for the dual-target experimental setup will also be presented and compared with experimental data. The main concepts of the longitudinal diagnostics based on the analysis of the CDR spectrum will be introduced. The limitations of the Kramers-Kronig technique as a tool for bunch profiling, and Coherent Synchrotron Radiation background contribution in the CDR spatial distribution will be discussed.