IBIC2012 - List of Authors (Sonnad, K.G.)

Paper

Title

Page

Electron Cloud Density Measurements using Resonant TE Waves at CesrTA

471

J.P. Sikora, M.G. Billing, D.O. Duggins, Y. Li, D. L. Rubin, R.M. Schwartz, K.G. Sonnad
CLASSE, Ithaca, New York, USA
S. De Santis
LBNL, Berkeley, California, USA

Funding: This work is supported by the US National Science Foundation PHY-0734867, PHY-1002467, and the US Department of Energy DE-FC02-08ER41538, DE-SC0006505.
The Cornell Electron Storage Ring has been reconfigured as a test accelerator (CesrTA) with beam energies ranging from 2 GeV to 5 GeV of either positrons or electrons. Research at CesrTA includes the study of the growth, decay and mitigation of electron clouds in the storage ring. Electron Cloud (EC) densities can be measured by resonantly exciting the beam-pipe with microwaves. The EC density will change beam-pipe's resonant frequency by an amount that is proportional to the local electric field squared of the standing waves. When the EC density is not uniform, it is especially important to know the standing wave pattern in order to obtain an absolute EC density measurement. We will present our current understanding of this technique in the context of new test sections of beam-pipe installed in August 2012. This will include bench measurements of standing waves in the beam-pipe, simulations of this geometry and recent EC density measurements with beam.

WECD01

Operation of a Single Pass, Bunch-by-bunch x-ray Beam Size Monitor for the CESR Test Accelerator Research Program

585

N.T. Rider, M.G. Billing, M. P. Ehrlichman, M.A. Palmer, D.P. Peterson, D. L. Rubin, J.P. Shanks, K.G. Sonnad
CLASSE, Ithaca, New York, USA
J.W. Flanagan
KEK, Ibaraki, Japan

Funding: This work is supported by the US National Science Foundation PHY-0734867, PHY-1002467, and the US Department of Energy DE-FC02-08ER41538, DE-SC0006505.
The CESR Test Accelerator (CesrTA) program targets the study of beam physics issues relevant to linear collider damping rings and other low emittance storage rings. This endeavor requires new instrumentation to study the beam dynamics along trains of ultra low emittance bunches. A key element of the program has been the design, commissioning and operation of an x-ray beam size monitor capable, on a turn by turn basis, of collecting single pass measurements of each individual bunch in a train over many thousands of turns. This new instrument utilizes custom, high bandwidth amplifiers and digitization hardware and firmware to collect signals from a linear InGaAs diode array. The instrument has been optimized to allow measurements with 3x10⁹ to 1x10¹¹ particles per bunch. This paper reports on the operational capabilities of this instrument, improvements for its performance, and the methods utilized in data analysis. Examples of key measurements which illustrate the instrument's performance are presented. This device demonstrates measurement capabilities applicable to future high energy physics accelerators and light sources.

Slides WECD01 [3.480 MB]

Paper	Title	Page
TUPB49	Electron Cloud Density Measurements using Resonant TE Waves at CesrTA	471
	J.P. Sikora, M.G. Billing, D.O. Duggins, Y. Li, D. L. Rubin, R.M. Schwartz, K.G. Sonnad CLASSE, Ithaca, New York, USA S. De Santis LBNL, Berkeley, California, USA
	Funding: This work is supported by the US National Science Foundation PHY-0734867, PHY-1002467, and the US Department of Energy DE-FC02-08ER41538, DE-SC0006505. The Cornell Electron Storage Ring has been reconfigured as a test accelerator (CesrTA) with beam energies ranging from 2 GeV to 5 GeV of either positrons or electrons. Research at CesrTA includes the study of the growth, decay and mitigation of electron clouds in the storage ring. Electron Cloud (EC) densities can be measured by resonantly exciting the beam-pipe with microwaves. The EC density will change beam-pipe's resonant frequency by an amount that is proportional to the local electric field squared of the standing waves. When the EC density is not uniform, it is especially important to know the standing wave pattern in order to obtain an absolute EC density measurement. We will present our current understanding of this technique in the context of new test sections of beam-pipe installed in August 2012. This will include bench measurements of standing waves in the beam-pipe, simulations of this geometry and recent EC density measurements with beam.

WECD01	Operation of a Single Pass, Bunch-by-bunch x-ray Beam Size Monitor for the CESR Test Accelerator Research Program	585
	N.T. Rider, M.G. Billing, M. P. Ehrlichman, M.A. Palmer, D.P. Peterson, D. L. Rubin, J.P. Shanks, K.G. Sonnad CLASSE, Ithaca, New York, USA J.W. Flanagan KEK, Ibaraki, Japan
	Funding: This work is supported by the US National Science Foundation PHY-0734867, PHY-1002467, and the US Department of Energy DE-FC02-08ER41538, DE-SC0006505. The CESR Test Accelerator (CesrTA) program targets the study of beam physics issues relevant to linear collider damping rings and other low emittance storage rings. This endeavor requires new instrumentation to study the beam dynamics along trains of ultra low emittance bunches. A key element of the program has been the design, commissioning and operation of an x-ray beam size monitor capable, on a turn by turn basis, of collecting single pass measurements of each individual bunch in a train over many thousands of turns. This new instrument utilizes custom, high bandwidth amplifiers and digitization hardware and firmware to collect signals from a linear InGaAs diode array. The instrument has been optimized to allow measurements with 3x10⁹ to 1x10¹¹ particles per bunch. This paper reports on the operational capabilities of this instrument, improvements for its performance, and the methods utilized in data analysis. Examples of key measurements which illustrate the instrument's performance are presented. This device demonstrates measurement capabilities applicable to future high energy physics accelerators and light sources.
	Slides WECD01 [3.480 MB]