A bunch compression scheme designed to obtain high efficiency in relativistic traveling-wave tube (TWT) amplifiers is reported. Bunch compression is achieved by making the bunches stay in more positive slopes of the axial electric field in the amplifier. The resulting momentum gradient across the bunch tends to oppose space-charge spreading and helps to sustain short bunch lengths for long dist...

We describe the calculated resistive wall impedance of the vacuum chamber and the corresponding growth rate of coupled-bunch instabilities for the VSX light source, a Japanese third generation VUV and soft X-ray source with a beam energy of 2 GeV. The impedance calculation was performed for the normal Al vacuum duct and the SiC duct, a higher-order mode (HOM) absorber of the damped RF cavity. T...

The SLAC design for a next-generation linear collider with center-of-mass energy of 0.5 to 1.0 TeV requires that multiple bunches (10) be accelerated on each RF fill. At the beam intensity (1O’O particles per bunch) and RF frequency (11 to 17 GHz) required, the beam would be highly unstable transversely. Using computer simulation and analytic models, we have studied several possible methods of ...

Linac-based X-ray-free-electron lasers (XFELs) require very short bunches of highbrightness electron beams with peak currents of the order of kilo-Amperes. These bunches cannot be produced directly in guns because space charge forces would destroy the brilliance within a short distance [1]. Increasing bunch peak currents with longitudinal compression at beam energies high enough to suppress spa...

A linear theory of wakefield excitation by a drive electron bunch in plasma–dielectric accelerating structure has been constructed for the case off-axis injection. The under investigation is round dielectric-loaded metal waveguide with channel charged particles, filled homogeneous cold plasma. developed was used to investigate spatial distribution bunch-excited transverse components, which act ...

May 1993 (4 Feedback Control of Coupled-Bunch Instabilities* J. D. Fox, N. Eisen, H. Hindi, I. Linscott, G. Oxoby, and L. Sapozhnikov Stanford Linear Accelerator Center, Stanford University, Stanford, CA 94309 USA and M. Serio, INFN Laboratori Nazionali, Frascati, Italy The next generation of synchrotron light sources and .particle accelerators will require active feedback systems to control mu...

We study single bunch stability with respect to monopole longitudinal oscillations in electron storage rings. Our analysis is different from the standard approach based on the linearized Vlasov equation. Rather, we reduce the full nonlinear Fokker-Planck equation to a Schrödingerlike equation which is subsequently analyzed by perturbation theory. We show that the Haissinski solution [3] may bec...

To obtain a luminosity of 1034cm-2sec-’ in a TeV Linear Collider (TLC), it will probably be necessary to accelerate many bunches in one filling of the RF structure. This has the effect of extracting more energy from the structure and thus enhances the overall efficiency of the accelerator. However, this leads to many problems. First, the train of bunches is subject to cumulative beam breakup tr...