PAC2013 - List of Authors (Schubert, S.G.)

Paper	Title	Page
THPAC12	Preparation and Investigation of Antimony Thin Films for Multi-Alkali Photocathodes	1163
	X. Liang, K. Attenkofer, T. Rao, S.G. Schubert, J. Smedley, E. Wang, Q. Wu BNL, Upton, Long Island, New York, USA I. Ben-Zvi, M. Ruiz-Osés Stony Brook University, Stony Brook, USA J. Jordan-Sweet IBM T. J. Watson Center, Yorktown Heights, New York, USA H.A. Padmore, J.J. Wong LBNL, Berkeley, California, USA
	Funding: Work is supported at BNL by Brookhaven Science Associates, LLC under Contract No. DEAC02-98CH10886 with the U.S. DOE. The work at Stony Brook is supported by the US DOE under grant DE-SC0005713. Multialikali antimonide cathodes provide high visible light quantum efficiency, with low thermal emittance and are excellent candidate materials for high average current next generation ERLs or high repetition rate FELs. Although these materials have some excellent characteristics, control of the growth mode of the thin film and ultimately the surface roughness is difficult and will effect the emittance that can be obtained in high gradient fields. To complement our growth studies of crystalline phases using x-ray diffraction studies, here we use the technique of grazing incidence small angle x-ray scattering (GI-SAXS) and atomic force microscopy (AFM) to measure the roughness as a function of film thickness. In this study, we demonstrate these techniques as applied to the growth of Sb, for a range of thicknesses, temperatures and growth rates, and show the wide range of moprphologies that can be formed with relatively minor changes in deposition conditions.

THPAC17	Alkali Antimonide Photocathodes for Everyone	1178
	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 J. DeFazio PHOTONIS USA PENNSYLVANIA, INC., Lancaster, USA H.A. Padmore, J.J. Wong LBNL, Berkeley, California, 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 have yielded the highest current on record for any photoinjector source (75 mA), with QE of ~10% for green light. However, traditional growth methods for these cathodes yield material that is inherently rough, leading to rise of the intrinsic emittance for high gradient injectors such as those for next-generation light sources. It this presentation we will explore the origin of roughness in these materials, as well as the growth dynamics, using in situ and in operando techniques, including Grazing Incidence X-ray Diffraction, Grazing Incidence Small Angle X-ray Scattering, X-ray reflectivity and in vacuum Atomic Force Microscopy.

Paper

Title

Page

Preparation and Investigation of Antimony Thin Films for Multi-Alkali Photocathodes

1163

X. Liang, K. Attenkofer, T. Rao, S.G. Schubert, J. Smedley, E. Wang, Q. Wu
BNL, Upton, Long Island, New York, USA
I. Ben-Zvi, M. Ruiz-Osés
Stony Brook University, Stony Brook, USA
J. Jordan-Sweet
IBM T. J. Watson Center, Yorktown Heights, New York, USA
H.A. Padmore, J.J. Wong
LBNL, Berkeley, California, USA

Funding: Work is supported at BNL by Brookhaven Science Associates, LLC under Contract No. DEAC02-98CH10886 with the U.S. DOE. The work at Stony Brook is supported by the US DOE under grant DE-SC0005713.
Multialikali antimonide cathodes provide high visible light quantum efficiency, with low thermal emittance and are excellent candidate materials for high average current next generation ERLs or high repetition rate FELs. Although these materials have some excellent characteristics, control of the growth mode of the thin film and ultimately the surface roughness is difficult and will effect the emittance that can be obtained in high gradient fields. To complement our growth studies of crystalline phases using x-ray diffraction studies, here we use the technique of grazing incidence small angle x-ray scattering (GI-SAXS) and atomic force microscopy (AFM) to measure the roughness as a function of film thickness. In this study, we demonstrate these techniques as applied to the growth of Sb, for a range of thicknesses, temperatures and growth rates, and show the wide range of moprphologies that can be formed with relatively minor changes in deposition conditions.

THPAC17

Alkali Antimonide Photocathodes for Everyone

1178

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
J. DeFazio
PHOTONIS USA PENNSYLVANIA, INC., Lancaster, USA
H.A. Padmore, J.J. Wong
LBNL, Berkeley, California, 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 have yielded the highest current on record for any photoinjector source (75 mA), with QE of ~10% for green light. However, traditional growth methods for these cathodes yield material that is inherently rough, leading to rise of the intrinsic emittance for high gradient injectors such as those for next-generation light sources. It this presentation we will explore the origin of roughness in these materials, as well as the growth dynamics, using in situ and in operando techniques, including Grazing Incidence X-ray Diffraction, Grazing Incidence Small Angle X-ray Scattering, X-ray reflectivity and in vacuum Atomic Force Microscopy.