2011 Particle Accelerator Conference - List of Keywords (octupole)

Paper	Title	Other Keywords	Page
WEP041	Weak Resonances Induced by Nonlinear Multipoles in a Quadrupole Doublet Lattice	linac, quadrupole, lattice, simulation	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.

WEP104	Transverse Feedback System and Instability Analysis at HLS	feedback, injection, damping, resonance	1674
	J.H. Wang, Y.B. Chen, W. Li, L. Liu, M. Meng, B.G. Sun, L. Wang, Y.L. Yang, Z.R. Zhou USTC/NSRL, Hefei, Anhui, People's Republic of China
	In this paper, we introduce the BxB transverse feedback systems at Hefei Light Source (HLS), which employ an analog system and a digital system. The experiment result of two systems. as well as the primary analysis of beam instability in HLS injection and operation are also presented in this paper.

THP065	Advances in High-Order Interaction Region Nonlinear Optics Correction at RHIC	sextupole, coupling, collider, interaction-region	2252
	C.M. Zimmer, S. Binello, M.G. Minty, F.C. Pilat BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. A method to indirectly measure and deterministically correct the higher order magnetic errors of the final focusing magnets in the Relativistic Heavy Ion Collider has been in place for several years at BNL. This method yields control over the effects of multi-pole errors through application of closed orbit bumps followed by analysis and correction of the resulting betatron tune shifts using multi-pole correctors. The process has recently been automated in order to provide more efficient and effective corrections. The tune resolution along with the reliability of tune measurements has also been improved significantly due to advances/upgrades in the betatron tune measurement system employed at RHIC (BBQ). Here we describe the foundation of the IR bump method, followed by recent improvements along with experimental data.

Paper

Title

Other Keywords

Page

WEP041

Weak Resonances Induced by Nonlinear Multipoles in a Quadrupole Doublet Lattice

linac, quadrupole, lattice, simulation

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.

WEP104

Transverse Feedback System and Instability Analysis at HLS

feedback, injection, damping, resonance

1674

J.H. Wang, Y.B. Chen, W. Li, L. Liu, M. Meng, B.G. Sun, L. Wang, Y.L. Yang, Z.R. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China

In this paper, we introduce the BxB transverse feedback systems at Hefei Light Source (HLS), which employ an analog system and a digital system. The experiment result of two systems. as well as the primary analysis of beam instability in HLS injection and operation are also presented in this paper.

THP065

Advances in High-Order Interaction Region Nonlinear Optics Correction at RHIC

sextupole, coupling, collider, interaction-region

2252

C.M. Zimmer, S. Binello, M.G. Minty, F.C. Pilat
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A method to indirectly measure and deterministically correct the higher order magnetic errors of the final focusing magnets in the Relativistic Heavy Ion Collider has been in place for several years at BNL. This method yields control over the effects of multi-pole errors through application of closed orbit bumps followed by analysis and correction of the resulting betatron tune shifts using multi-pole correctors. The process has recently been automated in order to provide more efficient and effective corrections. The tune resolution along with the reliability of tune measurements has also been improved significantly due to advances/upgrades in the betatron tune measurement system employed at RHIC (BBQ). Here we describe the foundation of the IR bump method, followed by recent improvements along with experimental data.