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Femto Second Bunch Slicing Diagnostics Using Coherent Synchrotron Radiation and Development of a Non-Destructive Bunch Length Monitor Based on Diffraction Radiation

English title Synchrotron Radiation and Development of a Non-Destructive Bunch Length Monitor Based on Diffraction Radiation
Applicant Schlott Volker
Number 112307
Funding scheme Project funding (Div. I-III)
Research institution Paul Scherrer Institut
Institution of higher education Paul Scherrer Institute - PSI
Main discipline Other disciplines of Physics
Start/End 01.11.2006 - 31.10.2009
Approved amount 125'172.00
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Keywords (11)

electro-optical bunch length monitor; coherent synchrotron radiation; coherent diffraction radiation; thz radiation; x-fel; femto-second bunch slicing; X-ray Free Electron Laser; femto second electron bunch length diagnostics; coherent THz radiation; electro-optic readout; fiber laser

Lay Summary (English)

Lay summary
X-Ray Free Electron Lasers (X-FEL) (for more information see e.g.: or will provide unprecedented power levels (GW) in the X-ray regime with femto second pulse durations allowing scientist to study nature at the atomic level with sufficient time resolution. Such accelerator-based 4th generation light sources require high quality electron bunches with extremely high peak currents (several kA) and femto second time structure. The online control and monitoring of such short electron bunches is one of the prerequisites for the successful operation of an X-FEL user facility. In this context, non-destructive electron bunch length diagnostics is being developed at the accelerator-based large research facilities of the Paul Scherrer Institut (PSI) in collaboration with the University of Berne. These types of measurements are based on the characterization of coherently emitted radiation (synchrotron radiation, diffraction radiation and transition radiation) from short relativistic electron bunches. For pico- (10-12) to femto (10-15) second long electron bunches, the spectral range of interest is in the THz region.

Our approach of a single-shot electro-optical autocorrelation (EOA) interferometer aims to provide a robust and reliable bunch length monitor, combining the high temporal resolution of step-scan interferometers and the fast (single-shot) response of THz gating technology. The electro-optical readout of the spatial THz interference pattern in a birefringent crystal (ZnTe or GaP) is accomplished by a specifically developed mode-locked Yb-doped fiber laser, which provides ~ 50 nJ pulse energy at 1030 nm wavelength with variable pulse length between 200 femto seconds and several pico seconds. The EOA-monitor will be tested using coherent diffraction radiation behind the 100 MeV pre-injector linac of the Swiss Light Source (SLS) and with coherently emitted synchrotron radiation at the SLS femto-slicing X-ray source.
Direct link to Lay Summary Last update: 21.02.2013

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