Author: Karataev, V.
Paper Title Page
MOPPP005 Feasibility of THz Source Based on Coherent Smith-Purcell Radiation Generated by Femtosecond Electron Bunches in Super-Radiant Regime 574
  • L.G. Sukhikh, K.P. Artyomov, A. Potylitsyn
    Tomsk Polytechnic University, Tomsk, Russia
  • A.S. Aryshev, J. Urakawa
    KEK, Ibaraki, Japan
  • V. Karataev
    JAI, Egham, Surrey, United Kingdom
  Nowadays there is a big interest to THz radiation that is a promising tool for investigations in material science, in biology, medicine and other fields. THz radiation for users is mostly produced by Light Sources that are big and complex machines. Because of this there are numerous activities in research and development of a compact THz source. One of the trends is based on using different types of radiation generated in coherent regime by short electron bunches. The promising radiation mechanism is coherent Smith-Purcell radiation (CSPR) that has monochromatic angular distribution and that is generated while the bunch travels in a vicinity of a grating. In this report we present simulated characteristics of frequency-locked coherent Smith-Purcell radiation (super-radiant regime) generated by a train of short (hundreds of femtosecond) 10 MeV electron bunches with THz spacing. The simulations are performed for different grating profiles and parameters using existing CSPR models and Particle-in-Cell simulation code. We also discuss the feasibility of the THz source based on CSPR and status of the experiment that is prepared at LUCX facility at KEK after the upgrade.  
WEPPR079 Observations of Microbunching Instabilities from a THz Port at Diamond Light Source 3114
  • W. Shields, G.E. Boorman, V. Karataev, A. Lyapin
    JAI, Egham, Surrey, United Kingdom
  • R. Bartolini, A.F.D. Morgan, G. Rehm
    Diamond, Oxfordshire, United Kingdom
  Diamond Light source is a third generation synchrotron facility dedicated to producing radiation of outstanding brightness. Above a threshold current, the electron bunches are susceptible to the phenomenon known as the microbunching instability. This instability is characterised by the onset of radiation bursts, the wavelength of which is around one order of magnitude shorter than the bunch length. Near threshold, the bursting occurs quasi-­‐periodically, however at higher currents, the bursting appears randomly. The high frequencies involved in these emissions make detection and analysis challenging. A port specifically for the investigation of mm wave emissions has recently been built at Diamond. Ultra fast Schottky Barrier Diode detectors have been installed to obtain data for only a small fraction of the bunch revolution time in an updated data acquisition system. The threshold current and subsequent evolution of the instability have been investigated.