BIW2012 - List of Authors (Shang, H.)

Paper	Title	Page
TUPG045	Chromaticity Measurement of the APS Booster	225
	C. Yao, H. Shang ANL, Argonne, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, under contract No. DE-AC02-06CH11357. Chromaticity plays an important role in the beam dynamics of circular accelerators and storage rings. The current operational 132-nm emittance lattice of the APS booster synchrotron has a natural x- and y- chromaticity of -7.15 and -21.1, respectively. The eddy-current-induced sextupole effect of the dipole vacuum chamber complicates the chromatic correction. Due to the current stability of ramp supplies and the resulting tune changes, we have not been able to measure chromaticity of the booster quantitatively until recently. Recent improvement in power supply current ramp has reduced the tune variation substantially, which enables us to measure chromaticity with sufficient accuracy. We performed simulation with elegant in order to understand the time-dependency of tunes and chromaticities. We present the measurement result and our analysis.

TUPG046	Development of a Horizontal Drive Stripline for the APS Transverse Feedback System	228
	C. Yao, Y.-C. Chae, S.H. Kim, L.H. Morrison, H. Shang ANL, Argonne, USA
	Funding: Work supported by U.S. Department of Energy, Office of Science, under contract No. DE-AC02-06CH11357 The APS storage ring has four striplines that are designed for tune measurement and feedback applications: two of them are part of the tune measurement system, and the other two are used as pickup and driver for the transverse feedback system. Drive tests with beam and simulation studies have shown insufficient kick strength in the horizontal plane for the desired damping rate. We determined that the main causes were the short length of the original stripline and the low beta-x function at the installation location. A new two-blade stripline was designed and installed in a high beta-x location of the storage ring. sddsoptimize, a multi-objective optimization, was employed to optimize the geometry of the stripline in order to achieve both impedance matching and high-shuntimpedance. Beam-based measurements showed an increase in kick strength from the original 0.25 μrad to 0.78 μrad. The stripline has been in operation for more than one year. This report describes the simulation, optimization, and the performance of the new stripline.

Paper

Title

Page

Chromaticity Measurement of the APS Booster

225

C. Yao, H. Shang
ANL, Argonne, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, under contract No. DE-AC02-06CH11357.
Chromaticity plays an important role in the beam dynamics of circular accelerators and storage rings. The current operational 132-nm emittance lattice of the APS booster synchrotron has a natural x- and y- chromaticity of -7.15 and -21.1, respectively. The eddy-current-induced sextupole effect of the dipole vacuum chamber complicates the chromatic correction. Due to the current stability of ramp supplies and the resulting tune changes, we have not been able to measure chromaticity of the booster quantitatively until recently. Recent improvement in power supply current ramp has reduced the tune variation substantially, which enables us to measure chromaticity with sufficient accuracy. We performed simulation with elegant in order to understand the time-dependency of tunes and chromaticities. We present the measurement result and our analysis.

TUPG046

Development of a Horizontal Drive Stripline for the APS Transverse Feedback System

228

C. Yao, Y.-C. Chae, S.H. Kim, L.H. Morrison, H. Shang
ANL, Argonne, USA

Funding: Work supported by U.S. Department of Energy, Office of Science, under contract No. DE-AC02-06CH11357
The APS storage ring has four striplines that are designed for tune measurement and feedback applications: two of them are part of the tune measurement system, and the other two are used as pickup and driver for the transverse feedback system. Drive tests with beam and simulation studies have shown insufficient kick strength in the horizontal plane for the desired damping rate. We determined that the main causes were the short length of the original stripline and the low beta-x function at the installation location. A new two-blade stripline was designed and installed in a high beta-x location of the storage ring. sddsoptimize, a multi-objective optimization, was employed to optimize the geometry of the stripline in order to achieve both impedance matching and high-shuntimpedance. Beam-based measurements showed an increase in kick strength from the original 0.25 μrad to 0.78 μrad. The stripline has been in operation for more than one year. This report describes the simulation, optimization, and the performance of the new stripline.