Sep 24 – 30, 2017
La Biodola, Isola d'Elba
Europe/Rome timezone

Heterodyne measurement of CTR from self-modulation instability (SMI) in AWAKE

Sep 27, 2017, 4:36 PM
SML, Sala Maria Luisa, HH

SML, Sala Maria Luisa, HH

talk WG1 - Electron Beams from Plasmas WG1_Parallel


Mr Falk Braunmueller (Max-Planck Institute for Physics)


We present the measurement setup and first results of a waveguide-integrated heterodyne measurement of coherent transition radiation (CTR) in the AWAKE experiment. As a result of the self-modulation instability, a pulse of strong CTR is expected from the modulated proton bunch passing through a CTR-screen. This radiation pulse, which has the length of the modulated part of the bunch and a frequency at the plasma frequency, is transported by overmoded waveguides over 15m to a heterodyne detector setup. With the two waveguide-integrated receivers, covering the frequency-bandwidths 90-140 GHz and 255-270 GHz, a significant fraction of the available plasma frequencies can be measured. The two mixers convert the CTR into a signal in the range of 5-20GHz that is measured on a fast oscilloscope, with a high spectral resolution of 1-3 GHz dominated by the pulse length. The first results measured with this setup on AWAKE, with the goal of precisely measuring the plasma frequency, will be presented.

Primary author

Mr Falk Braunmueller (Max-Planck Institute for Physics)


Prof. Allen Caldwell (Max Planck Institute for Physics) Dr Mikhail Martyanov (Max Planck Institut fur Physik, Munich) Prof. Patric Muggli (Max-Planck-Institut für Physik)

Presentation materials