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

Paper

Title

Page

Status and Upgrades of the NLCTA for Studies of Advanced Beam Acceleration, Dynamics, and Manipulation

130

M.P. Dunning, C. Adolphsen, T.S. Chu, E.R. Colby, A. Gilevich, C. Hast, R.K. Jobe, C. Limborg-Deprey, D.J. McCormick, B.D. McKee, J. Nelson, T.O. Raubenheimer, K. Soong, G.V. Stupakov, Z.M. Szalata, D.R. Walz, F. Wang, S.P. Weathersby, M. Woodley, D. Xiang
SLAC, Menlo Park, California, USA

The Next Linear Collider Test Accelerator (NLCTA) is a low-energy electron accelerator (120 MeV) at SLAC that is used for ultra-high gradient X-band RF structure testing and advanced accelerator research. Here we give an overview of the current program at the facility, including the E-163 direct laser acceleration experiment, the echo-enabled harmonic generation (EEHG) FEL experiment, narrow-band THz generation, coherent optical transition radiation (COTR) studies, microbunching instability studies, and X-band structure testing. We also present the upgrades that are currently underway and some future programs utilizing these upgrades, including extension of the EEHG experiments to higher harmonics, and an emittance exchange experiment.

MOP242

Evaluation of Temporal Diagnostic Techniques for Two-bunch FACET Beam

568

M.D. Litos, M.R. Bionta, V.A. Dolgashev, R.J. England, D. Fritz, A. Gilevich, P. Hering, M.J. Hogan
SLAC, Menlo Park, California, USA

Funding: Work supported by the U.S. Department of Energy under contract number DE-AC02-76SF00515
Three temporal diagnostic techniques are considered for use in the FACET facility at SLAC, which will incorporate a unique two-bunch beam for plasma wakefield acceleration experiments. The results of these experiments will depend strongly on the the inter-bunch spacing as well as the longitudinal profiles of the two bunches. A reliable, single-shot, high resolution measurement of the beam’s temporal profile is necessary to fully quantify the physical mechanisms underlying the beam driven plasma wakefield acceleration. In this study we show that a transverse deflecting cavity is the diagnostic which best meets our criteria.

TUODS3

Experimental Demonstration of the Echo-enabled Harmonic Generation Technique for Seeded FELs

D. Xiang, E.R. Colby, M.P. Dunning, A. Gilevich, C. Hast, R.K. Jobe, D.J. McCormick, J. Nelson, T.O. Raubenheimer, K. Soong, G.V. Stupakov, Z.M. Szalata, D.R. Walz, S.P. Weathersby, M. Woodley
SLAC, Menlo Park, California, USA

Funding: This work was supported by the US DOE under Contract No. DE-AC02-76SF00515.
Recently the scheme of echo-enabled harmonic generation (EEHG*) was proposed for short wavelength seeded FELs. This scheme allows far higher harmonic numbers to be accessed and makes the generation of coherent soft x-ray directly from a UV seed laser in a single stage possible**. In this paper we present the experimental demonstration*** of this echo harmonic technique at the Next Linear Collider Test Accelerator (NLCTA) at SLAC, where the coherent radiation at the harmonic frequency of the seed laser is generated using the 120 MeV electron beam. The experiment confirms the physics behind this technique and paves the way for applying it for seeded x-ray FELs.
* G. Stupakov, Phys. Rev. Lett, ZeHn2, 074801 (2009).
** D. Xiang and G. Stupakov, Phys. Rev. ST Accel. Beams 12, 030702 (2009).
*** D. Xiang, at al, Phys. Rev. Lett, ZeHn5, 114801 (2010).

Slides TUODS3 [3.936 MB]

THP168

FEL Beam Stability in the LCLS*

2423

J.L. Turner, R. Akre, A. Brachmann, F.-J. Decker, Y.T. Ding, P. Emma, Y. Feng, A.S. Fisher, J.C. Frisch, A. Gilevich, P. Hering, K. Horovitz, Z. Huang, R.H. Iverson, D. Kharakh, A. Krasnykh, J. Krzywinski, H. Loos, M. Messerschmidt, S.P. Moeller, H.-D. Nuhn, D.F. Ratner, T.J. Smith, J.J. Welch, J. Wu
SLAC, Menlo Park, California, USA

Funding: *This work was supported by U.S. Department of Energy, Office of Basic Energy Sciences, under Contract DE-AC02-76SF00515
During commissioning and operation of the Linac Coherent Light Source (LCLS) x-ray Free Electron Laser (FEL) at the SLAC National Accelerator Center electron and x-ray beam size, shape, centroid motion have been studied. The studies, sources, and remediation are summarized in this paper.

THP184

Tuning of the LCLS Linac for User Operation

2462

H. Loos, R. Akre, A. Brachmann, F.-J. Decker, Y.T. Ding, P. Emma, A.S. Fisher, J.C. Frisch, A. Gilevich, P. Hering, Z. Huang, R.H. Iverson, N. Lipkowitz, H.-D. Nuhn, D.F. Ratner, J.A. Rzepiela, T.J. Smith, J.L. Turner, J.J. Welch, W.E. White, J. Wu, G. Yocky
SLAC, Menlo Park, California, USA

Funding: This work was supported by U.S. Department of Energy, Office of Basic Energy Sciences, under Contract DE-AC02-76SF00515.
With the Linac Coherent Light Source (LCLS) now in its third user run, reliable electron beam delivery at various beam energies and charge levels has become of high operational importance. In order to reduce the beam tuning time required for such changes, several diagnostics and feed-forward procedures have been implemented. We report on improved lattice diagnostics to detect magnet, model, and diagnostics errors as well as on measurements of transverse RF kicks and static field contributions and corresponding correction procedures to facilitate beam energy changes.

Paper	Title	Page
MOP014	Status and Upgrades of the NLCTA for Studies of Advanced Beam Acceleration, Dynamics, and Manipulation	130
	M.P. Dunning, C. Adolphsen, T.S. Chu, E.R. Colby, A. Gilevich, C. Hast, R.K. Jobe, C. Limborg-Deprey, D.J. McCormick, B.D. McKee, J. Nelson, T.O. Raubenheimer, K. Soong, G.V. Stupakov, Z.M. Szalata, D.R. Walz, F. Wang, S.P. Weathersby, M. Woodley, D. Xiang SLAC, Menlo Park, California, USA
	The Next Linear Collider Test Accelerator (NLCTA) is a low-energy electron accelerator (120 MeV) at SLAC that is used for ultra-high gradient X-band RF structure testing and advanced accelerator research. Here we give an overview of the current program at the facility, including the E-163 direct laser acceleration experiment, the echo-enabled harmonic generation (EEHG) FEL experiment, narrow-band THz generation, coherent optical transition radiation (COTR) studies, microbunching instability studies, and X-band structure testing. We also present the upgrades that are currently underway and some future programs utilizing these upgrades, including extension of the EEHG experiments to higher harmonics, and an emittance exchange experiment.

MOP242	Evaluation of Temporal Diagnostic Techniques for Two-bunch FACET Beam	568
	M.D. Litos, M.R. Bionta, V.A. Dolgashev, R.J. England, D. Fritz, A. Gilevich, P. Hering, M.J. Hogan SLAC, Menlo Park, California, USA
	Funding: Work supported by the U.S. Department of Energy under contract number DE-AC02-76SF00515 Three temporal diagnostic techniques are considered for use in the FACET facility at SLAC, which will incorporate a unique two-bunch beam for plasma wakefield acceleration experiments. The results of these experiments will depend strongly on the the inter-bunch spacing as well as the longitudinal profiles of the two bunches. A reliable, single-shot, high resolution measurement of the beam’s temporal profile is necessary to fully quantify the physical mechanisms underlying the beam driven plasma wakefield acceleration. In this study we show that a transverse deflecting cavity is the diagnostic which best meets our criteria.

TUODS3	Experimental Demonstration of the Echo-enabled Harmonic Generation Technique for Seeded FELs
	D. Xiang, E.R. Colby, M.P. Dunning, A. Gilevich, C. Hast, R.K. Jobe, D.J. McCormick, J. Nelson, T.O. Raubenheimer, K. Soong, G.V. Stupakov, Z.M. Szalata, D.R. Walz, S.P. Weathersby, M. Woodley SLAC, Menlo Park, California, USA
	Funding: This work was supported by the US DOE under Contract No. DE-AC02-76SF00515. Recently the scheme of echo-enabled harmonic generation (EEHG) was proposed for short wavelength seeded FELs. This scheme allows far higher harmonic numbers to be accessed and makes the generation of coherent soft x-ray directly from a UV seed laser in a single stage possible. In this paper we present the experimental demonstration** of this echo harmonic technique at the Next Linear Collider Test Accelerator (NLCTA) at SLAC, where the coherent radiation at the harmonic frequency of the seed laser is generated using the 120 MeV electron beam. The experiment confirms the physics behind this technique and paves the way for applying it for seeded x-ray FELs. * G. Stupakov, Phys. Rev. Lett, ZeHn2, 074801 (2009). D. Xiang and G. Stupakov, Phys. Rev. ST Accel. Beams 12, 030702 (2009). * D. Xiang, at al, Phys. Rev. Lett, ZeHn5, 114801 (2010).
	Slides TUODS3 [3.936 MB]

THP168	FEL Beam Stability in the LCLS*	2423
	J.L. Turner, R. Akre, A. Brachmann, F.-J. Decker, Y.T. Ding, P. Emma, Y. Feng, A.S. Fisher, J.C. Frisch, A. Gilevich, P. Hering, K. Horovitz, Z. Huang, R.H. Iverson, D. Kharakh, A. Krasnykh, J. Krzywinski, H. Loos, M. Messerschmidt, S.P. Moeller, H.-D. Nuhn, D.F. Ratner, T.J. Smith, J.J. Welch, J. Wu SLAC, Menlo Park, California, USA
	Funding: *This work was supported by U.S. Department of Energy, Office of Basic Energy Sciences, under Contract DE-AC02-76SF00515 During commissioning and operation of the Linac Coherent Light Source (LCLS) x-ray Free Electron Laser (FEL) at the SLAC National Accelerator Center electron and x-ray beam size, shape, centroid motion have been studied. The studies, sources, and remediation are summarized in this paper.

THP184	Tuning of the LCLS Linac for User Operation	2462
	H. Loos, R. Akre, A. Brachmann, F.-J. Decker, Y.T. Ding, P. Emma, A.S. Fisher, J.C. Frisch, A. Gilevich, P. Hering, Z. Huang, R.H. Iverson, N. Lipkowitz, H.-D. Nuhn, D.F. Ratner, J.A. Rzepiela, T.J. Smith, J.L. Turner, J.J. Welch, W.E. White, J. Wu, G. Yocky SLAC, Menlo Park, California, USA
	Funding: This work was supported by U.S. Department of Energy, Office of Basic Energy Sciences, under Contract DE-AC02-76SF00515. With the Linac Coherent Light Source (LCLS) now in its third user run, reliable electron beam delivery at various beam energies and charge levels has become of high operational importance. In order to reduce the beam tuning time required for such changes, several diagnostics and feed-forward procedures have been implemented. We report on improved lattice diagnostics to detect magnet, model, and diagnostics errors as well as on measurements of transverse RF kicks and static field contributions and corresponding correction procedures to facilitate beam energy changes.