CERN Accelerating science

Article
Report number	SLAC-PUB-11209
Title	Virtual Accelerator for Accelerator Optics Improvement
Author(s)	Yan Yi Ton ; Cai Yun Hai ; Decker, Franz Josef ; Ecklund, Stanley ; Irwin, John ; Seeman, John ; Sullivan, Michael K ; Turner, J L ; Wienands, Ulrich
Affiliation	(SLAC)
Publication	2005
Imprint	30 Sep 2005
Number of pages	3
In:	21st IEEE Particle Accelerator Conference, Knoxville, TN, USA, 16 - 20 May 2005, pp.3426
Abstract	Through determination of all quadrupole strengths and sextupole feed-downs by fitting quantities derivable from precision orbit measurement, one can establish a virtual accelerator that matches the real accelerator optics. These quantities (the phase advances, the Green's functions, and the coupling eigen-plane ellipses tilt angles and axis ratios) are obtained by analyzing turn-by-turn Beam Position Monitor (BPM) data with a model-independent analysis (MIA). Instead of trying to identify magnet errors, a limited number of quadrupoles are chosen for optimized strength adjustment to improve the virtual accelerator optics and then applied to the real accelerator accordingly. These processes have been successfully applied to PEP-II rings for beta beating fixes, phase and working tune adjustments, and linear coupling reduction to improve PEP-II luminosity.

Corresponding record in: Inspire