IBIC2012 - List of Authors (Billing, M.G.)

Paper

Title

Page

UV/X-ray Diffraction Radiation for Non-intercepting Micron-scale Beam Size Measurement

24

L.M. Bobb, N. Chritin, T. Lefèvre
CERN, Geneva, Switzerland
M.G. Billing
CLASSE, Ithaca, New York, USA
L.M. Bobb, V. Karataev
JAI, Egham, Surrey, United Kingdom

Diffraction Radiation (DR) is produced when a relativistic charged particle moves in the vicinity of a medium. The electric field of the charged particle polarizes the target atoms which then oscillate, emitting radiation with a very broad spectrum. The spatial-spectral properties of DR are sensitive to a range of electron beam parameters. Furthermore, the energy loss due to DR is so small that the electron beam parameters are unchanged. Therefore DR can be used to develop non-invasive diagnostic tools. The aim of this project is to measure the transverse (vertical) beam size using incoherent DR. To achieve the micron-scale resolution required by CLIC, DR in the UV and X-ray spectral-range must be investigated. During the next few years, experimental validation of such a scheme will be conducted on the CesrTA at Cornell University, USA. Here we present the current status of the experiment preparation.

Slides MOCC01 [3.064 MB]

MOPB56

Electron Cloud Measurements using a Time Resolved Retarding Field Analyzer at CesrTA

201

J.P. Sikora, M.G. Billing, J.V. Conway, J.A. Crittenden, Y. Li, X. Liu, D. L. Rubin, C.R. Strohman
CLASSE, Ithaca, New York, USA
K. Kanazawa
KEK, Ibaraki, Japan
M.A. Palmer
Fermilab, Batavia, USA

Funding: This work is supported by the US National Science Foundation PHY-0734867, PHY-1002467, the US Department of Energy DE-FC02-08ER41538, DE-SC0006505 and US-Japan funding.
The Cornell Electron Storage Ring has been reconfigured as a test accelerator (CesrTA) with positron or electron beam energies ranging from 2 GeV to 5 GeV. An area of research at CesrTA is the study of the growth, decay and mitigation of electron clouds in the storage ring. With a Retarding Field Analyzer (RFA), cloud electrons pass into the detector through an array of small holes in the wall of the beam-pipe. The electrons are captured by several collectors, so that the electron flux can be measured vs. horizontal position. Up to now, we have integrated the collector currents to provide DC measurements. We have recently constructed a new Time Resolved RFA, where the collector currents can be observed on the time scale of the bunch train in the storage ring. We present a summary of the design, construction and commissioning of this device, as well as initial beam measurements at CesrTA.

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]

Paper	Title	Page
MOCC01	UV/X-ray Diffraction Radiation for Non-intercepting Micron-scale Beam Size Measurement	24
	L.M. Bobb, N. Chritin, T. Lefèvre CERN, Geneva, Switzerland M.G. Billing CLASSE, Ithaca, New York, USA L.M. Bobb, V. Karataev JAI, Egham, Surrey, United Kingdom
	Diffraction Radiation (DR) is produced when a relativistic charged particle moves in the vicinity of a medium. The electric field of the charged particle polarizes the target atoms which then oscillate, emitting radiation with a very broad spectrum. The spatial-spectral properties of DR are sensitive to a range of electron beam parameters. Furthermore, the energy loss due to DR is so small that the electron beam parameters are unchanged. Therefore DR can be used to develop non-invasive diagnostic tools. The aim of this project is to measure the transverse (vertical) beam size using incoherent DR. To achieve the micron-scale resolution required by CLIC, DR in the UV and X-ray spectral-range must be investigated. During the next few years, experimental validation of such a scheme will be conducted on the CesrTA at Cornell University, USA. Here we present the current status of the experiment preparation.
	Slides MOCC01 [3.064 MB]

MOPB56	Electron Cloud Measurements using a Time Resolved Retarding Field Analyzer at CesrTA	201
	J.P. Sikora, M.G. Billing, J.V. Conway, J.A. Crittenden, Y. Li, X. Liu, D. L. Rubin, C.R. Strohman CLASSE, Ithaca, New York, USA K. Kanazawa KEK, Ibaraki, Japan M.A. Palmer Fermilab, Batavia, USA
	Funding: This work is supported by the US National Science Foundation PHY-0734867, PHY-1002467, the US Department of Energy DE-FC02-08ER41538, DE-SC0006505 and US-Japan funding. The Cornell Electron Storage Ring has been reconfigured as a test accelerator (CesrTA) with positron or electron beam energies ranging from 2 GeV to 5 GeV. An area of research at CesrTA is the study of the growth, decay and mitigation of electron clouds in the storage ring. With a Retarding Field Analyzer (RFA), cloud electrons pass into the detector through an array of small holes in the wall of the beam-pipe. The electrons are captured by several collectors, so that the electron flux can be measured vs. horizontal position. Up to now, we have integrated the collector currents to provide DC measurements. We have recently constructed a new Time Resolved RFA, where the collector currents can be observed on the time scale of the bunch train in the storage ring. We present a summary of the design, construction and commissioning of this device, as well as initial beam measurements at CesrTA.

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]