Paper  Title  Page 

TUZBAB01  Experiments on Transverse Bunch Compression on the Princeton Paul Trap Simulator Experiment  810 


Funding: Research supported by the U. S. Department of Energy. The Paul Trap Simulator Experiment is a compact laboratory Paul trap that simulates a long, thin chargedparticle bunch coasting through a kilometerslong magnetic alternatinggradient (AG) transport system by putting the physicist in the beam's frameofreference. The transverse dynamics of particles in both systems are described by the same sets of equations, including all nonlinear spacecharge effects. The timedependent quadrupolar electric fields created by the confinement electrodes of a linear Paul trap correspond to the axiallydependent magnetic fields applied in the AG system. Results are presented from experiments in which the lattice period and strength are changed over the course of the experiment to transversely compress a beam with an initial depressedtune of 0.9. Instantaneous and smooth changes are considered. Emphasis is placed on determining the conditions that minimize the emittance growth and the number of halo particles produced after the beam compression. The results of PIC simulations performed with the WARP code agree well with the experimental data. Initial results from a newly installed laserinduced fluorescence diagnostic will also be discussed. 

Slides  
THPAS081  ParticleinCell Simulations of Halo Particle Production in Intense Charged Particle Beams Propagating Through a Quadrupole Focusing Field with Varying Lattice Amplitude  3669 


Funding: Research supported by the U. S. Department of Energy. The transverse compression and dynamics of intense charged particle beams, propagating through a periodic quadrupole lattice, play an important role in many accelerator physics applications. Typically, the compression can be achieved by means of increasing the focusing strength of the lattice along the beam propagation direction. However, beam propagation through the lattice transition region inevitably leads to a certain level of beam mismatch and halo formation. In this paper we present a detailed analysis of these phenomena using particleincell (PIC) numerical simulations performed with the WARP code. A new definition of beam halo is proposed in this work that provides the opportunity to carry out a quantitative analysis of halo production by a beam mismatch. 