Emittance growth rates for displaced beams

Halo formation and emittance growth of positron beams in plasmas.

An ultrarelativistic 28.5 GeV, 700-microm-long positron bunch is focused near the entrance of a 1.4-m-long plasma with a density n(e) between approximately equal to 10(13) and approximately equal to 5 x 10(14) cm(-3). Partial neutralization of the bunch space charge by the mobile plasma electrons results in a reduction in transverse size by a factor of approximately equal to 3 in the high emitt...

Emittance and entropy of electron beams

Creating high-brightness electron beams, which have many practical applications, is done with cathodes in regions with large electric field by field emission. The brightness is high when the current is high and the volume of the beam in phase space is small. An estimate of the phase space volume is the rms emittance. The simulations described in this report show that the beam emitted by a gated...

Single Pulse Emittance Measurement Technique for Intense Relativistic Electron Beams

Nonequilibrium transverse motion and emittance growth in ultrarelativistic space-charge dominated beams

The transverse dynamics of space-charge dominated beams are investigated both analytically and computationally, in order to understand the mechanisms for emittance oscillations and growth due to nonlinear space-charge fields. This work explores the role of space-charge dominated equilibrium and its relationship to phase space wave breaking, which is responsible for the irreversible emittance gr...

Halo Formation and Emittance Growth during Bunch Compression of High-current Heavy Ion Beams

A generation of halo particles and an emittance growth are investigated numerically for a highcurrent beam transport during a longitudinal bunch compression. The halo particles are generated during the drift compression with an alternating gradient confinement lattice in the transverse direction. The emittance growth is caused by the halo particle generation, and depends on the drift length for...