NAPAC2016 - List of Authors (Padmore, H.A.)

Paper	Title	Page
TUB1CO03	ALS-U: A Soft X-Ray Diffraction Limited Light Source	263
	C. Steier, A. Anders, J.M. Byrd, K. Chow, S. De Santis, R.M. Duarte, J.-Y. Jung, T.H. Luo, H. Nishimura, T. Oliver, J.R. Osborn, H.A. Padmore, G.C. Pappas, S. Persichelli, D. Robin, F. Sannibale, D. Schlueter, C. Sun, C.A. Swenson, M. Venturini, W.L. Waldron, E.J. Wallén, W. Wan, Y.C. Yang LBNL, Berkeley, California, USA
	Funding: This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Improvements in brightness and coherent flux of about two orders of magnitude over operational storage ring based light sources are possible using multi bend achromat lattice designs. These improvements can be implemented as upgrades of existing facilities, like the proposed upgrade of the Advanced Light Source (ALS-U). The upgrade proposal will reuse much of the existing infrastructure, thereby reducing cost and time needed to reach full scientific productivity on a large number of beamlines. We will report on the accelerator design progress as well as the details of the ongoing R+D program.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUB1CO03
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THPOA42	3D Modeling and Simulations of Electron Emission From Photocathodes With Controlled Rough Surfaces	1187
	D.A. Dimitrov, G.I. Bell, D.N. Smithe, C.D. Zhou Tech-X, Boulder, Colorado, USA I. Ben-Zvi, J. Smedley BNL, Upton, Long Island, New York, USA S.S. Karkare, H.A. Padmore LBNL, Berkeley, California, USA
	Funding: This work is supported by the US DOE Office of Science, department of Basic Energy Sciences under grant DE-SC0013190. Developments in materials design and synthesis have resulted in photocathodes that can have a high quantum efficiency (QE), operate at visible wavelengths, and are robust enough to operate in high electric field gradient photoguns, for application to free electron lasers and in dynamic electron microscopy and diffraction. However, synthesis often results in roughness, ranging from the nano to the microscale. The effect of this roughness in a high gradient accelerator is to produce a small transverse accelerating gradient, which therefore results in emittance growth. Although analytical formulations of the effects of roughness have been developed, a full theoretical model and experimental verification are lacking, and our work aims to bridge this gap. We report results on electron emission modeling and 3D simulations from photocathodes with controlled surface roughness similar to grated surfaces that have been fabricated by nanolithography. The simulations include both charge carrier dynamics in the photocathode material and a general electron emission modeling that includes field enhancement effects at rough surfaces. The models are being implemented in the VSim code.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THPOA42
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

ALS-U: A Soft X-Ray Diffraction Limited Light Source

263

C. Steier, A. Anders, J.M. Byrd, K. Chow, S. De Santis, R.M. Duarte, J.-Y. Jung, T.H. Luo, H. Nishimura, T. Oliver, J.R. Osborn, H.A. Padmore, G.C. Pappas, S. Persichelli, D. Robin, F. Sannibale, D. Schlueter, C. Sun, C.A. Swenson, M. Venturini, W.L. Waldron, E.J. Wallén, W. Wan, Y.C. Yang
LBNL, Berkeley, California, USA

Funding: This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
Improvements in brightness and coherent flux of about two orders of magnitude over operational storage ring based light sources are possible using multi bend achromat lattice designs. These improvements can be implemented as upgrades of existing facilities, like the proposed upgrade of the Advanced Light Source (ALS-U). The upgrade proposal will reuse much of the existing infrastructure, thereby reducing cost and time needed to reach full scientific productivity on a large number of beamlines. We will report on the accelerator design progress as well as the details of the ongoing R+D program.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUB1CO03

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOA42

3D Modeling and Simulations of Electron Emission From Photocathodes With Controlled Rough Surfaces

1187

D.A. Dimitrov, G.I. Bell, D.N. Smithe, C.D. Zhou
Tech-X, Boulder, Colorado, USA
I. Ben-Zvi, J. Smedley
BNL, Upton, Long Island, New York, USA
S.S. Karkare, H.A. Padmore
LBNL, Berkeley, California, USA

Funding: This work is supported by the US DOE Office of Science, department of Basic Energy Sciences under grant DE-SC0013190.
Developments in materials design and synthesis have resulted in photocathodes that can have a high quantum efficiency (QE), operate at visible wavelengths, and are robust enough to operate in high electric field gradient photoguns, for application to free electron lasers and in dynamic electron microscopy and diffraction. However, synthesis often results in roughness, ranging from the nano to the microscale. The effect of this roughness in a high gradient accelerator is to produce a small transverse accelerating gradient, which therefore results in emittance growth. Although analytical formulations of the effects of roughness have been developed, a full theoretical model and experimental verification are lacking, and our work aims to bridge this gap. We report results on electron emission modeling and 3D simulations from photocathodes with controlled surface roughness similar to grated surfaces that have been fabricated by nanolithography. The simulations include both charge carrier dynamics in the photocathode material and a general electron emission modeling that includes field enhancement effects at rough surfaces. The models are being implemented in the VSim code.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THPOA42

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)