FEL2013 - List of Keywords (synchrotron)

Paper	Title	Other Keywords	Page
MOPSO06	Paraxial Approximation in CSR Modeling Using the Discontinuous Galerkin Method	impedance, vacuum, simulation, radiation	32
	D. A. Bizzozero, J.A. Ellison, K.A. Heinemann, S.R. Lau UNM, Albuquerque, New Mexico, USA
	Funding: This work was primarily supported by DOE under DE-FG-99ER41104. The work of DB and SL was partially supported by NSF grant PHY 0855678 to the University of New Mexico. We continue our study* of CSR from a bunch moving on an arbitrary curved trajectory. In that study we developed an accurate 2D CSR Vlasov-Maxwell code (VM3@A) and applied it to a four dipole chicane bunch compressor. Our starting point now is the well-established paraxial approximation** with boundary conditions for a perfectly conducting vacuum chamber with uniform cross-section. This is considerably different from our previous approach* where we calculated the fields from an integral over history, using parallel plate boundary conditions. In this study, we present a Discontinuous Galerkin (DG) method for the paraxial approximation equations. Our basic tool is a MATLAB DG code on a GPU using MATLAB's gpuArray; the code was developed by one of us (DB). We discuss our results in the context of previous work and outline future applications for DG, including a Vlasov-Maxwell study. * See PRST-AB 12 080704 (2009) and Proceedings from ICAP2012 TUSDC2. ** See PRST-AB 7 054403 (2004), PRST-AB 12 104401 (2009) and Jpn. J. Appl. Phys. 51 016401 (2012).

TUPSO76	In Situ Characterization of ALKALI Antimonide Photocathodes	cathode, scattering, emittance, brightness	403
	J. Smedley, K. Attenkofer, S.G. Schubert BNL, Upton, Long Island, New York, USA I. Ben-Zvi, X. Liang, E.M. Muller, M. Ruiz-Osés Stony Brook University, Stony Brook, USA M. DeMarteau Fermilab, Batavia, USA H.A. Padmore, J.J. Wong LBNL, Berkeley, California, USA A.R. Woll Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA J. Xie ANL, Argonne, USA
	Funding: The authors wish to acknowledge the support of the US DOE, under Contract No. KC0407-ALSJNT-I0013, DE-AC02-98CH10886 and DE-SC0005713. Use of CHESS is supported by NSF award DMR-0936384. Alkali antimonide photocathodes are a prime candidate for use in high-brightness photoinjectors of free electron lasers and 4th generation light sources. These materials have complex growth kinetics - many methods exist for forming the compounds, each with different grain size, roughness, and crystalline texture. These parameters impact the performance of the cathodes, including efficiency, intrinsic emittance and lifetime. In situ analysis of the growth of these materials has allowed investigation of correlations between cathode structure and growth parameters and the resulting quantum efficiency (QE). The best cathodes have a QE at 532 nm in excess of 6% and are structurally textured K2CsSb with grain sizes in excess of 20 nm. X-ray reflection (XRR) has been used to characterize the roughness evolution of the cathode, while X-ray Diffraction (XRD) has been used to characterize the texture, grain size and stoichometry.

WEPSO43	EEHG and Femtoslicing at DELTA	electron, undulator, radiation, laser	594
	R. Molo, H. Huck, M. Huck, M. Höner, S. Khan, A. Schick, P. Ungelenk DELTA, Dortmund, Germany
	The ultrashort-pulse facility at DELTA (a 1.5-GeV synchrotron light source operated by the TU Dortmund University) based on the coherent harmonic generation (CHG) technique will be upgraded using echo-enabled harmonic generation (EEHG) in order to reach shorter wavelengths. A laser-induced energy modulation is employed in the CHG and EEHG schemes to create a periodic electron density modulation, but can also be used to generate ultrashort pulses of incoherent radiation at arbitrary wavelengths by transversely displacing the off-energy electrons(femtoslicing). A new storage-ring lattice for DELTA will be presented that not only offers enough free straight sections for an EEHG and femtoslicing setup, but also allows to operate both radiation sources simultaneously.

WEPSO58	Status Report of the Short-pulse Facility at the Delta Storage Ring	radiation, laser, electron, klystron	642
	A. Schick, H. Huck, M. Huck, M. Höner, S. Khan, R. Molo, P. Ungelenk DELTA, Dortmund, Germany
	Funding: * Work supported by DFG, BMBF and by the Federal State NRW. At DELTA, a 1.5-GeV synchrotron light source operated by the TU Dortmund university, a short-pulse facility employing the CHG (Coherent Harmonic Generation) principle is in operation. Here, the interaction of an intense, ultrashort laser pulse and electrons in an undulator leads to microbunching of a small fraction of the electrons in the bunch. As a consequence, ultrashort, coherent synchrotron-radiation pulses in the VUV regime are emitted at harmonics of the incident laser wavelength. In addition, coherent THz pulses on the sub-ps timescale are generated. In this paper, the latest improvements of the facility and recent measurements are presented, including investigation of the transverse coherence and detection of the CHG radiation using photoemission spectroscopy in a VUV beamline.

Paper

Title

Other Keywords

Page

MOPSO06

Paraxial Approximation in CSR Modeling Using the Discontinuous Galerkin Method

impedance, vacuum, simulation, radiation

32

D. A. Bizzozero, J.A. Ellison, K.A. Heinemann, S.R. Lau
UNM, Albuquerque, New Mexico, USA

Funding: This work was primarily supported by DOE under DE-FG-99ER41104. The work of DB and SL was partially supported by NSF grant PHY 0855678 to the University of New Mexico.
We continue our study* of CSR from a bunch moving on an arbitrary curved trajectory. In that study we developed an accurate 2D CSR Vlasov-Maxwell code (VM3@A) and applied it to a four dipole chicane bunch compressor. Our starting point now is the well-established paraxial approximation** with boundary conditions for a perfectly conducting vacuum chamber with uniform cross-section. This is considerably different from our previous approach* where we calculated the fields from an integral over history, using parallel plate boundary conditions. In this study, we present a Discontinuous Galerkin (DG) method for the paraxial approximation equations. Our basic tool is a MATLAB DG code on a GPU using MATLAB's gpuArray; the code was developed by one of us (DB). We discuss our results in the context of previous work and outline future applications for DG, including a Vlasov-Maxwell study.
* See PRST-AB 12 080704 (2009) and Proceedings from ICAP2012 TUSDC2.
** See PRST-AB 7 054403 (2004), PRST-AB 12 104401 (2009) and Jpn. J. Appl. Phys. 51 016401 (2012).

TUPSO76

In Situ Characterization of ALKALI Antimonide Photocathodes

cathode, scattering, emittance, brightness

403

J. Smedley, K. Attenkofer, S.G. Schubert
BNL, Upton, Long Island, New York, USA
I. Ben-Zvi, X. Liang, E.M. Muller, M. Ruiz-Osés
Stony Brook University, Stony Brook, USA
M. DeMarteau
Fermilab, Batavia, USA
H.A. Padmore, J.J. Wong
LBNL, Berkeley, California, USA
A.R. Woll
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
J. Xie
ANL, Argonne, USA

Funding: The authors wish to acknowledge the support of the US DOE, under Contract No. KC0407-ALSJNT-I0013, DE-AC02-98CH10886 and DE-SC0005713. Use of CHESS is supported by NSF award DMR-0936384.
Alkali antimonide photocathodes are a prime candidate for use in high-brightness photoinjectors of free electron lasers and 4th generation light sources. These materials have complex growth kinetics - many methods exist for forming the compounds, each with different grain size, roughness, and crystalline texture. These parameters impact the performance of the cathodes, including efficiency, intrinsic emittance and lifetime. In situ analysis of the growth of these materials has allowed investigation of correlations between cathode structure and growth parameters and the resulting quantum efficiency (QE). The best cathodes have a QE at 532 nm in excess of 6% and are structurally textured K2CsSb with grain sizes in excess of 20 nm. X-ray reflection (XRR) has been used to characterize the roughness evolution of the cathode, while X-ray Diffraction (XRD) has been used to characterize the texture, grain size and stoichometry.

WEPSO43

EEHG and Femtoslicing at DELTA

electron, undulator, radiation, laser

594

R. Molo, H. Huck, M. Huck, M. Höner, S. Khan, A. Schick, P. Ungelenk
DELTA, Dortmund, Germany

The ultrashort-pulse facility at DELTA (a 1.5-GeV synchrotron light source operated by the TU Dortmund University) based on the coherent harmonic generation (CHG) technique will be upgraded using echo-enabled harmonic generation (EEHG) in order to reach shorter wavelengths. A laser-induced energy modulation is employed in the CHG and EEHG schemes to create a periodic electron density modulation, but can also be used to generate ultrashort pulses of incoherent radiation at arbitrary wavelengths by transversely displacing the off-energy electrons(femtoslicing). A new storage-ring lattice for DELTA will be presented that not only offers enough free straight sections for an EEHG and femtoslicing setup, but also allows to operate both radiation sources simultaneously.

WEPSO58

Status Report of the Short-pulse Facility at the Delta Storage Ring

radiation, laser, electron, klystron

642

A. Schick, H. Huck, M. Huck, M. Höner, S. Khan, R. Molo, P. Ungelenk
DELTA, Dortmund, Germany

Funding: * Work supported by DFG, BMBF and by the Federal State NRW.
At DELTA, a 1.5-GeV synchrotron light source operated by the TU Dortmund university, a short-pulse facility employing the CHG (Coherent Harmonic Generation) principle is in operation. Here, the interaction of an intense, ultrashort laser pulse and electrons in an undulator leads to microbunching of a small fraction of the electrons in the bunch. As a consequence, ultrashort, coherent synchrotron-radiation pulses in the VUV regime are emitted at harmonics of the incident laser wavelength. In addition, coherent THz pulses on the sub-ps timescale are generated. In this paper, the latest improvements of the facility and recent measurements are presented, including investigation of the transverse coherence and detection of the CHG radiation using photoemission spectroscopy in a VUV beamline.