The purpose of this paper is to develop a self-consistent kinetic description of helically distorted relativistic electron beam equilibria for free electron laser applications. In particular, radially confined equilibria are considered for a helically distorted electron beam propagating in the combined transverse wiggler and uniform axial guide 0 fields described by B =B oz+6=Bo z-Bcosk zkxBsin...

Beam-plasma instabilities are a key physical process in many astrophysical phenomena. Within the fireball model of Gamma ray bursts, they first mediate a relativistic collisionless shock before they produce upstream the turbulence needed for the Fermi acceleration process. While non-relativistic systems are usually governed by flow-aligned unstable modes, relativistic ones are likely to be domi...

Design and experimental results are presented from two high power microwave generation experiments utilizing a high repetition rate induction linac generated electron beam. A relativistic klystron has generated more than 100 MW microwave pulses in X-band for 50 ns without pulse shortening or breakdown. Design studies for the first cyclotron autoresonance maser (CARM) amplifier using an inductio...

• T he re g io nal situa t ion is ripe. Po l i t ical changes in Cro a t ia and Serbia and within B o s n ia away from the na t io nalist fo rces that ma de war in the 1990s ma ke it possible for the int e r na t io nal community to move mo re aggressively to break fina nc ial and military ties between Belgra de and Bosnian Serb na t io na l i s t s, just as the link between Za g reb and Bosnia...

A reexamination of the semiclassical approach of the relativistic electron indicates a possible variation of its helicity for electric and magnetic static fields applied along its global motion due to zitterbewegung effects, proportional to the anomalous part of the magnetic moment.

The generation of an ultrashort relativistic electron bunch from a strong laser-plasma interaction have been studied by particle-in-cell simulations and observed experimentally. The electron beam was generated from the plasma created by focusing a Ti: sapphire 12 TW (tera watt) laser pulse at the edge of helium gas jet expanded into the vacuum from a pulsed supersonic nozzle. The laser pulse du...

We propose a novel method for tailoring the current distribution of relativistic electron bunches. The technique relies on a recently proposed transverse-to-longitudinal phase space exchange. The bunch is transversely shaped and the phase space exchange mechanism converts this transverse profile into a current profile. The technique provides a tool for generating arbitrary current profiles in a...

Non-luminous relativistic electron beams above thunderclouds have been detected by the radio signals of low frequency ∼40–400 kHz which they radiate. The electron beams occur ∼2–9 ms after positive cloud-to-ground lightning discharges at heights between ∼22–72 km above thunderclouds. Intense positive lightning discharges can also cause sprites which occur either above or prior to the electron b...

It is shown that the motion of an individual test electron in a low-density relativistic electron beam propagating through a realizable planar-wiggler magnetic field is nonintegrable and can become chaotic. The chaoticity, which is induced by the transverse spatial inhomogeneities in the wiggler field, poses limits on the wiggler field amplitude and the beam size for beam propagation and free e...

Older industrial districts, often rich with history and architecture, are paradoxically central yet decayin g features of the modern US urban landscape. However, several such areas are experiencing major renaissances through individual sparks of private business investm ent. Lower Downtown (LoDo) Denver is a well-known example of this phenomenon; less recogn ised is the in ̄ uential role of craf...