2011 Particle Accelerator Conference - List of Authors (Wang, J. G.)

Paper	Title	Page
WEP039	Tracking Stripped Proton Particles in SNS Ring Injection Momentum Dump Line	1567
	J. G. Wang ORNL, Oak Ridge, Tennessee, USA
	3D computer simulations are performed to study magnetic field distributions and particle trajectories along the SNS ring injection momentum dump line. Optical properties and transfer maps along the dump line are calculated. The stripped proton particle distributions on the dump window are analyzed. The study has provided useful information for the redesign of the SNS ring injection beam dump.

WEP041	Weak Resonances Induced by Nonlinear Multipoles in a Quadrupole Doublet Lattice	1570
	Y. Zhang, J. G. Wang ORNL, Oak Ridge, Tennessee, USA
	Funding: This submission was sponsored by a contractor of the United States Government under contract DE-AC05-00OR22725 with the United States Department of Energy. In this paper we report the effects on beam dynamics from two intrinsic multipole components of a quadrupole magnet – dodecapole and psedu-octupole, in a quadrupole doublet lattice. Weak resonances at transverse phase advances 60°; and 90°; per cell, which may contribute to halo formation and beam loss in a linac, are shown from multi-particle tracking simulations. Although the net effect of the psedu-octupole component alone is very small due to substantial cancellations within the same magnet, its existence may significantly enhance the weak resonances which are induced by the dodecapole component of quadrupole magnets. The combined contributions of these two magnetic field components may not be simply linear-scaled because of the extreme nonlinear nature.

Paper

Title

Page

Tracking Stripped Proton Particles in SNS Ring Injection Momentum Dump Line

1567

J. G. Wang
ORNL, Oak Ridge, Tennessee, USA

3D computer simulations are performed to study magnetic field distributions and particle trajectories along the SNS ring injection momentum dump line. Optical properties and transfer maps along the dump line are calculated. The stripped proton particle distributions on the dump window are analyzed. The study has provided useful information for the redesign of the SNS ring injection beam dump.

WEP041

Weak Resonances Induced by Nonlinear Multipoles in a Quadrupole Doublet Lattice

1570

Y. Zhang, J. G. Wang
ORNL, Oak Ridge, Tennessee, USA

Funding: This submission was sponsored by a contractor of the United States Government under contract DE-AC05-00OR22725 with the United States Department of Energy.
In this paper we report the effects on beam dynamics from two intrinsic multipole components of a quadrupole magnet – dodecapole and psedu-octupole, in a quadrupole doublet lattice. Weak resonances at transverse phase advances 60°; and 90°; per cell, which may contribute to halo formation and beam loss in a linac, are shown from multi-particle tracking simulations. Although the net effect of the psedu-octupole component alone is very small due to substantial cancellations within the same magnet, its existence may significantly enhance the weak resonances which are induced by the dodecapole component of quadrupole magnets. The combined contributions of these two magnetic field components may not be simply linear-scaled because of the extreme nonlinear nature.