Synchrotron-betatron parametric instability in free-electron lasers.

Quantitative X-ray phase-contrast microtomography from a compact laser-driven betatron source

X-ray phase-contrast imaging has recently led to a revolution in resolving power and tissue contrast in biomedical imaging, microscopy and materials science. The necessary high spatial coherence is currently provided by either large-scale synchrotron facilities with limited beamtime access or by microfocus X-ray tubes with rather limited flux. X-rays radiated by relativistic electrons driven by...

Free-electron lasers and JSR.

Lasers , Free - Electron

Free-electron lasers are radiation sources, based on the coherent emission of synchrotron radiation of relativistic electrons within an undulator or wiggler. The resonant radiation wavelength depends on the electron beam energy and can be tuned over the entire spectrum from micrometer to X-ray radiation. The emission level of free-electron lasers is several orders of magnitude larger than the e...

Gauss-schell sources as models for synchrotron radiation.

Gauss-Schell light sources are considered as models for synchrotron radiation. These sources can be viewed as random superpositions of coherent Gaussian beams. The relationships of the various widths that can be defined for the description of intensity and coherence, as related to the widths of the electron beam and the single-electron radiation (diffraction) pattern, are summarized. The descri...

Further Studies on Betatron Sidebands Due to Electron Clouds

We have observed vertical betatron sidebands in the transverse beam spectra of positron bunches at the KEKB LER which are associated with the presence of electron clouds in single-beam studies[1], and which are also associated with a loss of luminosity when the KEKB beams are in collision[2]. The sidebands appear to be signals of a fast head-tail instability due to short-range wakes within the ...