Search for a chirp of a synchrotron x-ray beam at the European Synchrotron Radiation Facility: I. Experiments

摘要

Abstract: In an earlier paper the emission of synchrotron radiation was studied theoretically for the current induced by a single electron interacting with a bending magnet showing that a chirp of the hard x-ray could be expected that could be used for a compression of x-ray bunches using dispersive optics. In this paper we will present results of an experimental study that was conducted on a bending magnet beamline (BM5) at the ESRF to learn if such a chirp exists for an electron bunch as a function of the x-ray energy and of the emission angle below and above the electron orbit plane. Our results for the pulse shape show that such a chirp could not be clearly detected at a level of several tens of picoseconds FWHM. This means that the phase relationships of all the electrons producing the x- ray bunch are averaged out leading to the absence of a net chirp. However, a fast Fourier transform of the observed signal showed that there was a phase lag. This will be described in a companion paper. Here, the details of the experimentally observed time structure will be given. !6