2011 Particle Accelerator Conference - List of Authors (Calvey, J.R.)

Paper	Title	Page
MOP214	Methods for Quantitative Interpretation of Retarding Field Analyzer Data	501
	J.R. Calvey, J.A. Crittenden, G. Dugan, M.A. Palmer CLASSE, Ithaca, New York, USA M.A. Furman LBNL, Berkeley, California, USA K.C. Harkay ANL, Argonne, USA
	Funding: US Department of Energy grant DE-FC02-08ER41538 US National Science Foundation grant PHY-0734867 Over the course of the CesrTA program at Cornell, over 30 Retarding Field Analyzers (RFAs) have been installed in the CESR storage ring, and a great deal of data has been taken with them. These devices measure the local electron cloud density and energy distribution, and can be used to evaluate the efficacy of different cloud mitigation techniques. Obtaining a quantitative understanding of RFA data requires use of cloud simulation programs, as well as a detailed model of the detector itself. In a drift region, the RFA can be modeled by postprocessing the output of a simulation code, and one can obtain best fit values for important simulation parameters with a chi-square minimization method.

MOP228	TE Wave Measurements of the Electron Cloud in a Dipole Magnetic Field	531
	S. De Santis, J.M. Byrd LBNL, Berkeley, California, USA J.R. Calvey, J. Joseph, J.A. Livezey, J.P. Sikora, K.G. Sonnad CLASSE, Ithaca, New York, USA K.C. Hammond Harvard University, Cambridge, Massachusetts, USA
	Funding: Work supported by the U.S. Department of Energy under Contract Nos. DE-AC02-05CH1123 and DE-FC02-08ER41538 and by the National Science Foundation Grant PHY-0734867. The TE wave propagation method has become a widely used technique for measuring electron cloud density in an accelerator beampipe. In most instances the wave very low power is not capable of affecting the low-energy electrons distribution. During experiments in the CESR Damping Ring Test Accelerator (Cesr-TA), we have observed a particular situation where a resonance between the wave and a dipole magnetic field produces a large modification in the electron cloud distribution that can be measured by other detectors. We believe this resonance is strongly dependent on the geometry of standing waves pattern that discontinuities in the beampipe generate. We present measurements in Cesr-TA, which describe the effect and are in support of our hypothesis.

Paper

Title

Page

Methods for Quantitative Interpretation of Retarding Field Analyzer Data

501

J.R. Calvey, J.A. Crittenden, G. Dugan, M.A. Palmer
CLASSE, Ithaca, New York, USA
M.A. Furman
LBNL, Berkeley, California, USA
K.C. Harkay
ANL, Argonne, USA

Funding: US Department of Energy grant DE-FC02-08ER41538 US National Science Foundation grant PHY-0734867
Over the course of the CesrTA program at Cornell, over 30 Retarding Field Analyzers (RFAs) have been installed in the CESR storage ring, and a great deal of data has been taken with them. These devices measure the local electron cloud density and energy distribution, and can be used to evaluate the efficacy of different cloud mitigation techniques. Obtaining a quantitative understanding of RFA data requires use of cloud simulation programs, as well as a detailed model of the detector itself. In a drift region, the RFA can be modeled by postprocessing the output of a simulation code, and one can obtain best fit values for important simulation parameters with a chi-square minimization method.

MOP228

TE Wave Measurements of the Electron Cloud in a Dipole Magnetic Field

531

S. De Santis, J.M. Byrd
LBNL, Berkeley, California, USA
J.R. Calvey, J. Joseph, J.A. Livezey, J.P. Sikora, K.G. Sonnad
CLASSE, Ithaca, New York, USA
K.C. Hammond
Harvard University, Cambridge, Massachusetts, USA

Funding: Work supported by the U.S. Department of Energy under Contract Nos. DE-AC02-05CH1123 and DE-FC02-08ER41538 and by the National Science Foundation Grant PHY-0734867.
The TE wave propagation method has become a widely used technique for measuring electron cloud density in an accelerator beampipe. In most instances the wave very low power is not capable of affecting the low-energy electrons distribution. During experiments in the CESR Damping Ring Test Accelerator (Cesr-TA), we have observed a particular situation where a resonance between the wave and a dipole magnetic field produces a large modification in the electron cloud distribution that can be measured by other detectors. We believe this resonance is strongly dependent on the geometry of standing waves pattern that discontinuities in the beampipe generate. We present measurements in Cesr-TA, which describe the effect and are in support of our hypothesis.