We report on measurements of the bunch energy spectrum at the end of the SLAC linac. Using the spectra obtained for two different linac rf phases we obtain both the bunch induced voltage and the longitudinal distribution of the bunch. The measurement results are compared with theoretical predictions. In particular, the induced voltage is in good agreement with that obtained using the calculated...

We present a technique for the design and verification of efficient bunch-by-bunch controllers for damping longitudinal multibunch instabilities. The controllers attempt to optimize the use of available feedback amplifier power one of the most expensive components of a feedback system and define the limits of closed loop system performance. Our design technique alternates between analytic compu...

The end effect in a bunched beam is caused by the space-charge forces, which accelerate particles at the bunch head and decelerate particles at the bunch tail. It occurs in high-current linear accelerators and rings [1]. In the University of Maryland Electron Ring (UMER) project [2,3,4], the energy of particles at the very ends of a rectangular bunch is 15% different from that of the main part ...

The effect of ultrafast electron beam bunch dynamics on single shot electro-optic sampling detection schemes is examined. It is shown that ultrashort electron bunch fields of adequate magnitude can dynamically impose additional bandwidth on laser probe pulses. The significance of this effect is evaluated by comparing the dynamics of the laser probe to that of the nonradiative field of a single ...

In this article we study effects of microbunch cooperative electromagnetic radiation in a bend on transverse beam dynamics. An overtaking radiative interaction between different parts of the bunch results in three major forces variable along the bunch. Longitudinal force leads to energy loss and causes the bunch emittance growth in the bend due to the dispersion effect. Radial force consists of...

Electron bunches with charge densities ρ of the order of 102 to 103 [nC/cm3], energies between 20. and 100. [MeV], peak current > 100 [A], bunch lengths between 0.3 and 1.8 [cm], and bunch charge of 2.0 to 20. [nC] are relevant to the design of Free Electron Lasers and future linear colliders. In this paper we present the results of numerical simulations performed with a particle in a cell (pic...

We described here the way of production of ≤ 100 fs bursts of X and gamma radiation by Compton backscattering of a laser bunch which have been swept along the electron trajectory. In the method described the time duration of the secondary radiation does not depend on electron bunch length and is shorter than duration of the primary laser bunch by factor 1/ –the number of resolved spots of sweep...

A method for computing transverse multibunch growth rates and frequency shifts in rings, which has been described previously [1, 2], is applied to the PEP-II B factory. The method allows multibunch modes with different internal-bunch oscillation modes to couple to one another, similar to single-bunch mode coupling. Including coupling between the multibunch modes gives effects similar to those s...

PEP-II, the asymmetric B-Factory at SLAC, has delivered a luminosity of 3.1 · 10 cm s. This was achieved with 692 bunches in a basic "by-3" bunch pattern. Many gaps in the bunch train were necessary to suppress a blow-up of the positron beam due to an electron cloud instability (ECI). The actual pattern had 10 bunches in a row (every third bucket), then 6 bunches missing. This 48-bucket long pa...