2011 Particle Accelerator Conference - List of Authors (Dunning, M.P.)

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.

MOP015

An X-band Gun Test Area at SLAC

133

C. Limborg-Deprey, C. Adolphsen, T.S. Chu, M.P. Dunning, C. Hast, R.K. Jobe, E.N. Jongewaard, A.E. Vlieks, D.R. Walz, F. Wang
SLAC, Menlo Park, California, USA
S.G. Anderson, F.V. Hartemann, T.L. Houck, R.A. Marsh
LLNL, Livermore, California, USA

Funding: Work supported by the U.S. DOE Contract No. DE-AC03-76SF00515
The XTA (X-Band Test Area) is being assembled in the NLCTA tunnel of the SLAC National Laboratory to serve as a test facility for new RF guns. The first gun to be tested will be an upgraded version of the 5.6 cell, 200MV/m peak field X-band designed at SLAC in 2003 for the Compton Scattering experiment run in ASTA. This new version includes some features implemented in 2006 on the LCLS gun such as racetrack couplers, increased mode separation and elliptical irises. These upgrades were discussed in collaboration with LLNL since the same gun will be used as a driver for the LLNL Gamma-ray Source. Our beamline includes an X-band accelerating section which takes the electron beam up to 100 MeV and an electron beam measurement station. Other X-Band guns such as the UCLA Hybrid gun will be characterized at our facility.

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]

THP170

Observation and Characterization of Coherent Optical Radiation and Microbunching Instability in the SLAC Next Linear Collider Test Accelerator

2426

S.P. Weathersby, M.P. Dunning, C. Hast, R.K. Jobe, D.J. McCormick, J. Nelson, D. Xiang
SLAC, Menlo Park, California, USA

The NLC Test Accelerator (NLCTA) at SLAC is currently configured for a proof-of-principle echo-enabled harmonic generation (EEHG) experiment using a 120 MeV beam. During commissioning, unexpected coherent optical undulator radiation (CUR) and coherent optical transition radiation (COTR) was observed when beam is accelerated off-crest and compressed after the chicanes. The CUR and COTR is likely due to a microbunching instability where initial small modulations in the cathode drive laser pulse are compressed and amplified. In this paper we present the observation and characterization of the CUR, COTR and microbunching instability at NLCTA.
* D. Xiang et al., "Demonstration of the Echo-Enabled Harmonic Generation Technique for Short-Wavelength Seeded Free Electron Lasers", PRL 105, 114801, 2010.

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.

MOP015	An X-band Gun Test Area at SLAC	133
	C. Limborg-Deprey, C. Adolphsen, T.S. Chu, M.P. Dunning, C. Hast, R.K. Jobe, E.N. Jongewaard, A.E. Vlieks, D.R. Walz, F. Wang SLAC, Menlo Park, California, USA S.G. Anderson, F.V. Hartemann, T.L. Houck, R.A. Marsh LLNL, Livermore, California, USA
	Funding: Work supported by the U.S. DOE Contract No. DE-AC03-76SF00515 The XTA (X-Band Test Area) is being assembled in the NLCTA tunnel of the SLAC National Laboratory to serve as a test facility for new RF guns. The first gun to be tested will be an upgraded version of the 5.6 cell, 200MV/m peak field X-band designed at SLAC in 2003 for the Compton Scattering experiment run in ASTA. This new version includes some features implemented in 2006 on the LCLS gun such as racetrack couplers, increased mode separation and elliptical irises. These upgrades were discussed in collaboration with LLNL since the same gun will be used as a driver for the LLNL Gamma-ray Source. Our beamline includes an X-band accelerating section which takes the electron beam up to 100 MeV and an electron beam measurement station. Other X-Band guns such as the UCLA Hybrid gun will be characterized at our facility.

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]

THP170	Observation and Characterization of Coherent Optical Radiation and Microbunching Instability in the SLAC Next Linear Collider Test Accelerator	2426
	S.P. Weathersby, M.P. Dunning, C. Hast, R.K. Jobe, D.J. McCormick, J. Nelson, D. Xiang SLAC, Menlo Park, California, USA
	The NLC Test Accelerator (NLCTA) at SLAC is currently configured for a proof-of-principle echo-enabled harmonic generation (EEHG) experiment using a 120 MeV beam. During commissioning, unexpected coherent optical undulator radiation (CUR) and coherent optical transition radiation (COTR) was observed when beam is accelerated off-crest and compressed after the chicanes. The CUR and COTR is likely due to a microbunching instability where initial small modulations in the cathode drive laser pulse are compressed and amplified. In this paper we present the observation and characterization of the CUR, COTR and microbunching instability at NLCTA. * D. Xiang et al., "Demonstration of the Echo-Enabled Harmonic Generation Technique for Short-Wavelength Seeded Free Electron Lasers", PRL 105, 114801, 2010.