相关论文: A new description of space charge induced beam hal…

An intense non-uniform particle beam exhibits strong emittance growth and halo formation in focusing channels due to nonlinear space charge forces of the beam. This phenomenon limits beam brightness and results in particle losses. The…

An interpretation of the formation of halo in accelerators based on quantum-like theory by a diffraction model is given in terms of the transversal beam motion. Physical implications of the longitudinal dynamics are also examined

An interpretation of the formation of halo in accelerators based on quantum-like theory by a diffraction model is given in terms of the transversal beam motion. Physical implications of the longitudinal dynamics are also examined.

Here, we present a novel algorithm that discriminates between bound and unbound particles by consideration of the gravitational potential from an accelerated reference frame -- also referred to as `the boosted potential'. Particles are…

The formation of the beam halo in charged particle accelerators is studied in the framework of a stochastic-hydrodynamic model for the collective motion of the particle beam. In such a stochastic-hydrodynamic theory the density and the…

Dark matter halos are typically defined as spheres that enclose some overdensity, but these sharp, somewhat arbitrary boundaries introduce non-physical artifacts such as backsplash halos, pseudo-evolution, and an incomplete accounting of…

An interpretation of the ``halo problem'' in accelerators based on quantum-like diffraction is given. Comparison between this approach and the others based on classical mechanics equations is discussed.

Space charge effects can be very important for the dynamics of intense particle beams, as they repeatedly pass through nonlinear focusing elements, aiming to maximize the beam's luminosity properties in the storage rings of a high energy…

A dark matter halo model is developed postulating a new state of matter, entities which have internal spin-like terms. Their motion in an external Schwarzschild metric is discussed. The internal spin motion contributes to the centrifugal…

This paper shows that gravitating bodies travelling through the Galaxy can trap lighter interstellar particles that pass nearby with small relative velocities onto temporarily-bound orbits. The capture mechanism is driven by the Galactic…

Dark matter haloes have long been recognized as one of the fundamental building blocks of large scale structure formation models. Despite their importance -- or perhaps because of it! -- halo definitions continue to evolve towards more…

Due to the potentially adverse effects of the generation of halo particles in intense proton beams, it is imperative to have a clear understanding of the mechanisms that can lead to halo formation for current and proposed high- intensity…

High-intensity beams in modern linacs are frequently encircled by diffuse halos, which drive sustained particle losses and result in gradual degradation of accelerating structures. In large part, the growth of halos is facilitated by…

A halo is an intrinsically quantum object defined as a bound state of a spatial size which extends deeply into the classically forbidden region. Previously, halos have been observed in bound states of two and less frequently of three atoms.…

We investigate unbound dark matter particles in halos by tracing particle trajectories in a simulation run to the far future (a = 100). We find that the traditional sum of kinetic and potential energies is a very poor predictor of which…

We explore the potential impact of colored noise on space-charge-induced halo formation. By coupling particle orbits to parametric resonance, colored noise due to space-charge fluctuations and/or imperfections in the beamline can eject…

It has been empirically observed in both experiments and particle-in-cell simulations that space-charge-dominated beams suffer strong growth in statistical phase-space area (degraded quality) and particle losses in alternating gradient…

Accurate modelling of the one-to-two halo transition has long been difficult to achieve. We demonstrate that physically motivated halo definitions that respect the bimodal phase-space distribution of dark matter particles near halos…

Circular particle accelerators at the energy frontier are based on superconducting magnets that are extremely sensitive to beam losses as these might induce quenches, i.e.\ transitions to the normal-conducting state. Furthermore, the energy…

In situ particle acceleration is probably occuring in cluster radio haloes. This is suggested by the uniformity and extent of the haloes, given that spatial diffusion is slow and that radiative losses limit particle lifetimes. Stochastic…