2011 Particle Accelerator Conference - List of Authors (Lumpkin, A.H.)

Paper

Title

Page

Experimental Studies on Coherent Synchrotron Radiation in the Emittance Exchange Line at the Fermilab A0 Photoinjector

322

J.C.T. Thangaraj, M.D. Church, H.T. Edwards, A.S. Johnson, A.H. Lumpkin, P. Piot, J. Ruan, J.K. Santucci, Y.-E. Sun, R.M. Thurman-Keup
Fermilab, Batavia, USA

Future accelerators will employ advanced beam conditioning systems such as emittance exchangers to manipulate high brightness beams. Coherent synchrotron radiation (CSR) in the dipoles could limit the performance of the emittance exchanger. In this paper, we report the experimental and simulation studies on measuring coherent synchrotron radiation and its effects on the beam at the A0 photoinjector in the emittance exchange line. We show how CSR can be used to measure bunch length of the beam. We also report on the diagnostic scheme based on a weak skew quad in the emittance exchange line to study the CSR effects on the beam and other beam dynamics.

MOP219

Initial Beam-Profiling Tests with the NML Prototype Station at the Fermilab A0 Photoinjector

510

A.H. Lumpkin, M.D. Church, R.H. Flora, A.S. Johnson, J. Ruan, J.K. Santucci, V.E. Scarpine, Y.-E. Sun, R.M. Thurman-Keup, M. Wendt
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
Beam-profile diagnostics are being developed for a superconducting (SC) radiofrequency (RF) Test Accelerator that is currently under construction at the New Muon Lab (NML) at Fermilab. The facility’s design goals include the replication of the pulse train proscribed for the International Linear Collider (ILC). An RF photoelectric gun based on the DESY design will generate the beam. In test-beam mode a low-power beam will be characterized with intercepting radiation converter screens: either a 100-micron thick YAG:Ce single crystal scintillator or a 1-micron thin Al optical transition radiation (OTR) foil. This prototype station was constructed by RadiaBeam Technologies under a contract with Fermilab. In both cases the screen surface was normal to the beam direction followed by a downstream 45-degree mirror that directed the radiation into the optical system. The optical system has better than 20 (10) micron rms spatial resolution when covering a vertical field of view of 18(5) mm. These initial tests were performed at the A0 Photoinjector at a beam energy of ~15 MeV and with micropulse charges from 25 to 500 pC for beam sizes of 45 to 250 microns. Example results will be presented.

MOP220

The Feasibility of Near-Field ODR Beam-Size Monitoring at 23 GeV at FACET

513

A.H. Lumpkin
Fermilab, Batavia, USA
M.J. Hogan
SLAC, Menlo Park, California, USA
P. Muggli
USC, Los Angeles, California, USA
C. Yao
ANL, Argonne, USA

Funding: Work partially supported by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy
Extension of near-field optical diffraction radiation (ODR) imaging to the 23 GeV beams at the proposed FACET facility at SLAC has been evaluated. The beam- size sensitivity at the 10- to 20- μm σ level based on a simple model will be reported. Polarization effects are also seen to be important and will be discussed. The comparisons to previous experimental results and the modeling results indicate sufficient feasibility for planning of the experiments in the coming year.

MOP225

Initial Characterization of a Commercial Electron Gun for Profiling High Intensity Proton Beams in Project X

525

R.M. Thurman-Keup, A.S. Johnson, A.H. Lumpkin, J.C.T. Thangaraj, D.H. Zhang
Fermilab, Batavia, USA
W. Blokland
ORNL, Oak Ridge, Tennessee, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
Measuring the profile of a high intensity proton beam is problematic in that traditional invasive techniques such as flying wires don't survive the encounter with the beam. One alternative is the use of an electron beam as a probe of the charge distribution in the proton beam as was done at the Spallation Neutron Source at ORNL. Here we present an initial characterization of the beam from a commercial electron gun from Kimball Physics, intended for use in the Fermilab Main Injector for Project X.

MOP226

Transverse Emittance and Phase Space Program Developed for Use at the Fermilab A0 Photoinjector

528

R.M. Thurman-Keup, A.S. Johnson, A.H. Lumpkin, J. Ruan
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The Fermilab A0 Photoinjector is a 16MeV high intensity, high brightness electron Linac developed for advanced accelerator R&D. One of the key parameters for the electron beam is the transverse beam emittance. Here we report on a newly developed MATLAB based GUI program used for transverse emittance measurements using the multi-slit technique. This program combines the image acquisition and post-processing tools for determining the transverse phase space parameters with uncertainties.

TUOCN4

Subpicosecond Electron Bunch Train Production Using a Phase-Space Exchange Technique

755

Y.-E. Sun, A.S. Johnson, A.H. Lumpkin, J. Ruan, R.M. Thurman-Keup
Fermilab, Batavia, USA
T.J. Maxwell, P. Piot
Northern Illinois University, DeKalb, Illinois, USA

Funding: The work was supported by the Fermi Research Alliance, LLC under the DOE Contract No. DE-AC02-07CH11359, and by Northern Illinois University under the DOE Contract No. DE-FG02-08ER41532.
Our recent experimental demonstration of a photoinjector electron bunch train with sub-picosecond structures is reported in this paper. The experiment is accomplished by converting an initially horizontal beam intensity modulation into a longitudinal phase space modulation, via a beamline capable of exchanging phase-space coordinates between the horizontal and longitudinal degrees of freedom. The initial transverse modulation is produced by intercepting the beam with a multislit mask prior to the exchange. We also compare our experimental results with numerical simulations.

Slides TUOCN4 [1.761 MB]

WEP024

Near-ideal Emittance Exchange at the Fermilab Photoinjector

1543

A.S. Johnson, H.T. Edwards, A.H. Lumpkin, J. Ruan, J.K. Santucci, R.M. Thurman-Keup
Fermilab, Batavia, USA

The A0 Photoinjector at Fermilab is presently home to an emittance exchange (EEX) experiment. The emittance exchange beamline consists of a 3.9 GHz normal conducting deflecting mode cavity flanked by two doglegs. Electron bunches with charges of 250 pC and energy of 14.3 MeV are routinely sent through the exchanger. Here we present results of a 1:1 transverse and longitudinal emittance exchange.

Paper	Title	Page
MOP121	Experimental Studies on Coherent Synchrotron Radiation in the Emittance Exchange Line at the Fermilab A0 Photoinjector	322
	J.C.T. Thangaraj, M.D. Church, H.T. Edwards, A.S. Johnson, A.H. Lumpkin, P. Piot, J. Ruan, J.K. Santucci, Y.-E. Sun, R.M. Thurman-Keup Fermilab, Batavia, USA
	Future accelerators will employ advanced beam conditioning systems such as emittance exchangers to manipulate high brightness beams. Coherent synchrotron radiation (CSR) in the dipoles could limit the performance of the emittance exchanger. In this paper, we report the experimental and simulation studies on measuring coherent synchrotron radiation and its effects on the beam at the A0 photoinjector in the emittance exchange line. We show how CSR can be used to measure bunch length of the beam. We also report on the diagnostic scheme based on a weak skew quad in the emittance exchange line to study the CSR effects on the beam and other beam dynamics.

MOP219	Initial Beam-Profiling Tests with the NML Prototype Station at the Fermilab A0 Photoinjector	510
	A.H. Lumpkin, M.D. Church, R.H. Flora, A.S. Johnson, J. Ruan, J.K. Santucci, V.E. Scarpine, Y.-E. Sun, R.M. Thurman-Keup, M. Wendt Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. Beam-profile diagnostics are being developed for a superconducting (SC) radiofrequency (RF) Test Accelerator that is currently under construction at the New Muon Lab (NML) at Fermilab. The facility’s design goals include the replication of the pulse train proscribed for the International Linear Collider (ILC). An RF photoelectric gun based on the DESY design will generate the beam. In test-beam mode a low-power beam will be characterized with intercepting radiation converter screens: either a 100-micron thick YAG:Ce single crystal scintillator or a 1-micron thin Al optical transition radiation (OTR) foil. This prototype station was constructed by RadiaBeam Technologies under a contract with Fermilab. In both cases the screen surface was normal to the beam direction followed by a downstream 45-degree mirror that directed the radiation into the optical system. The optical system has better than 20 (10) micron rms spatial resolution when covering a vertical field of view of 18(5) mm. These initial tests were performed at the A0 Photoinjector at a beam energy of ~15 MeV and with micropulse charges from 25 to 500 pC for beam sizes of 45 to 250 microns. Example results will be presented.

MOP220	The Feasibility of Near-Field ODR Beam-Size Monitoring at 23 GeV at FACET	513
	A.H. Lumpkin Fermilab, Batavia, USA M.J. Hogan SLAC, Menlo Park, California, USA P. Muggli USC, Los Angeles, California, USA C. Yao ANL, Argonne, USA
	Funding: Work partially supported by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy Extension of near-field optical diffraction radiation (ODR) imaging to the 23 GeV beams at the proposed FACET facility at SLAC has been evaluated. The beam- size sensitivity at the 10- to 20- μm σ level based on a simple model will be reported. Polarization effects are also seen to be important and will be discussed. The comparisons to previous experimental results and the modeling results indicate sufficient feasibility for planning of the experiments in the coming year.

MOP225	Initial Characterization of a Commercial Electron Gun for Profiling High Intensity Proton Beams in Project X	525
	R.M. Thurman-Keup, A.S. Johnson, A.H. Lumpkin, J.C.T. Thangaraj, D.H. Zhang Fermilab, Batavia, USA W. Blokland ORNL, Oak Ridge, Tennessee, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. Measuring the profile of a high intensity proton beam is problematic in that traditional invasive techniques such as flying wires don't survive the encounter with the beam. One alternative is the use of an electron beam as a probe of the charge distribution in the proton beam as was done at the Spallation Neutron Source at ORNL. Here we present an initial characterization of the beam from a commercial electron gun from Kimball Physics, intended for use in the Fermilab Main Injector for Project X.

MOP226	Transverse Emittance and Phase Space Program Developed for Use at the Fermilab A0 Photoinjector	528
	R.M. Thurman-Keup, A.S. Johnson, A.H. Lumpkin, J. Ruan Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. The Fermilab A0 Photoinjector is a 16MeV high intensity, high brightness electron Linac developed for advanced accelerator R&D. One of the key parameters for the electron beam is the transverse beam emittance. Here we report on a newly developed MATLAB based GUI program used for transverse emittance measurements using the multi-slit technique. This program combines the image acquisition and post-processing tools for determining the transverse phase space parameters with uncertainties.

TUOCN4	Subpicosecond Electron Bunch Train Production Using a Phase-Space Exchange Technique	755
	Y.-E. Sun, A.S. Johnson, A.H. Lumpkin, J. Ruan, R.M. Thurman-Keup Fermilab, Batavia, USA T.J. Maxwell, P. Piot Northern Illinois University, DeKalb, Illinois, USA
	Funding: The work was supported by the Fermi Research Alliance, LLC under the DOE Contract No. DE-AC02-07CH11359, and by Northern Illinois University under the DOE Contract No. DE-FG02-08ER41532. Our recent experimental demonstration of a photoinjector electron bunch train with sub-picosecond structures is reported in this paper. The experiment is accomplished by converting an initially horizontal beam intensity modulation into a longitudinal phase space modulation, via a beamline capable of exchanging phase-space coordinates between the horizontal and longitudinal degrees of freedom. The initial transverse modulation is produced by intercepting the beam with a multislit mask prior to the exchange. We also compare our experimental results with numerical simulations.
	Slides TUOCN4 [1.761 MB]

WEP024	Near-ideal Emittance Exchange at the Fermilab Photoinjector	1543
	A.S. Johnson, H.T. Edwards, A.H. Lumpkin, J. Ruan, J.K. Santucci, R.M. Thurman-Keup Fermilab, Batavia, USA
	The A0 Photoinjector at Fermilab is presently home to an emittance exchange (EEX) experiment. The emittance exchange beamline consists of a 3.9 GHz normal conducting deflecting mode cavity flanked by two doglegs. Electron bunches with charges of 250 pC and energy of 14.3 MeV are routinely sent through the exchanger. Here we present results of a 1:1 transverse and longitudinal emittance exchange.