To minimize emittance growth in a long linac, it is necessary to control the wakefields by correcting the beam orbit excursions. In addition, the particle energy is made to vary along the length of the bunch to introduce a damping, -known as the BNS damping, to the beam break-up efiect. In this paper, we use a two-particle model to examine the relative magnitudes of the various orbit and disper...

The paper describes a new beam dynamics code for simulation of space charge effects in isochronous cyclotrons. The program assumes that the beam consists of many point macro-particles. The code uses a set of simplified equations of motion. It adopts continuous and slow acceleration approximation that allows one to separate betatron motion from slower energy-phase motion. Thus, the particle radi...

Trapping in, or scattering off, resonances driven by space charge (SC) or electron cloud (EC) in conjunction with synchrotron motion can explain observations of slow beam loss and emittance growth, which are often accompanied by changes in the longitudinal beam profile. This talk will review recent progress in understanding and modeling the underlying mechanisms, highlight the differences and s...

Aerodynamic lens inlets have revolutionized aerosol mass spectrometry by allowing the introduction of a very narrow particle beam into a vacuum chamber for subsequent analysis. The real-time measurement of particle beam width after an aerodynamic lens is of interest for two reasons: (1) it allows a correction to be made to the measured particle concentration if the beam is so broad, due to poor...

Test particle motion is analyzed for a matched intense charged-particle beam in a periodic focusing solenoidal magnetic field to assess the effects of beam intensity on inducing chaotic particle motion and halo formation.

Charged-particle beam optics, or the theory of transport of charged-particle beams through electromagnetic systems, is traditionally dealt with using classical mechanics. Though the classical treatment has been very successful, in designing and working of numerous charged-particle optical devices, it is natural to look for a deeper understanding based on the quantum theory, since any system is ...

Using a macroparticle model for both synchrotron motion and beta-tron motion, we provide formulae for the beam centroid shift, the tune shifts and the growth rates of the longitudinal and transverse head-tail instabilities. Both single turn and multi-turn eeects are included. The transient amplitudes based on the two-particle model are estimated. We estimate the microwave instability for the mu...

Futuremachines such as the Electron Ion Collider (MEIC), linac-ring machines (eRHIC) or LHeC are particularly sensitive to beam-beam effects. This is the limiting factor for long-term stability and high luminosity reach. The complexity of the non-linear dynamics makes it challenging to perform such simulations typically requiring millions of turns. Until recently, most of the methods have invol...

We demonstrate the transfer of orbital angular momentum from a light beam to a trapped low-index particle. The particle is trapped in a dark annular region of a high-order Bessel beam and rotates around the beam axis due to scattering from the helical wave fronts of the light beam. A general theoretical geometrical optics model is developed that, applied to our specific situation, corroborates ...