ERL2019 - List of Authors (Maxson, J.M.)

Paper	Title	Page
WECOWBS02	High Current Polarized Electron Source Development
	L. Cultrera, J. Bae, I.V. Bazarov, A. Galdi, F. Ikponmwen, J.M. Maxson Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: DOE DE-SC0019122 We report on negative electron affinity (NEA) of GaAs using robust layers based on the use of Cs, Sb and Oxygen. A detailed parametric study has been performed on the growth conditions and using the equivalent Sb thickness as main parameter. Our results confirm that dark lifetime (measured as 1/e decay of the quantum efficiency as function of time) of the GaAs activated using this method is improved by a factor 10. More importantly the operating lifetime (measured as 1/e decay of the quantum efficiency as function of the extracted charge) is improved by a factor 40 with respect to Cs-O activated GaAs operated under similar conditions. Such improvements on the lifetime are achieved at expenses of a slightly reduced QE and electron spin polarization.
	Slides WECOWBS02 [36.273 MB]
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WEPNEC21	Decoupling Cathode and Lattice Emittance Contributions from a 100 pC, 100 MeV Electron Injector System	112
	N.P. Norvell SLAC, Menlo Park, California, USA M.B. Andorf, I.V. Bazarov, C.M. Gulliford, J.M. Maxson Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	We present simulation results to decouple the emittance contributions that are intrinsic from the injector lattice versus emittance contributions due to the quality of the cathode out of a 100 MeV electron injector system. Using ASTRA driven by the NSGA-II genetic algorithm, we optimized the LCLS-II injector system with a zero emittance cathode. We then imposed FEL specific energy constraints and show how the Pareto Front solution shifts. Lastly, we reoptimized at various cathode emittances to map out the dependence of cathode emittance versus final emittance out of the injector system. We then determined the cathode quality needed to hit a 0.1 mm mrad 95% rms transverse emittance specification out of the current LCLS-II injector system.
	Poster WEPNEC21 [3.227 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ERL2019-WEPNEC21
About •	paper received ※ 01 October 2019 paper accepted ※ 07 November 2019 issue date ※ 24 June 2020
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

WECOWBS02

High Current Polarized Electron Source Development

L. Cultrera, J. Bae, I.V. Bazarov, A. Galdi, F. Ikponmwen, J.M. Maxson
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: DOE DE-SC0019122
We report on negative electron affinity (NEA) of GaAs using robust layers based on the use of Cs, Sb and Oxygen. A detailed parametric study has been performed on the growth conditions and using the equivalent Sb thickness as main parameter. Our results confirm that dark lifetime (measured as 1/e decay of the quantum efficiency as function of time) of the GaAs activated using this method is improved by a factor 10. More importantly the operating lifetime (measured as 1/e decay of the quantum efficiency as function of the extracted charge) is improved by a factor 40 with respect to Cs-O activated GaAs operated under similar conditions. Such improvements on the lifetime are achieved at expenses of a slightly reduced QE and electron spin polarization.

Slides WECOWBS02 [36.273 MB]

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WEPNEC21

Decoupling Cathode and Lattice Emittance Contributions from a 100 pC, 100 MeV Electron Injector System

112

N.P. Norvell
SLAC, Menlo Park, California, USA
M.B. Andorf, I.V. Bazarov, C.M. Gulliford, J.M. Maxson
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

We present simulation results to decouple the emittance contributions that are intrinsic from the injector lattice versus emittance contributions due to the quality of the cathode out of a 100 MeV electron injector system. Using ASTRA driven by the NSGA-II genetic algorithm, we optimized the LCLS-II injector system with a zero emittance cathode. We then imposed FEL specific energy constraints and show how the Pareto Front solution shifts. Lastly, we reoptimized at various cathode emittances to map out the dependence of cathode emittance versus final emittance out of the injector system. We then determined the cathode quality needed to hit a 0.1 mm mrad 95% rms transverse emittance specification out of the current LCLS-II injector system.

Poster WEPNEC21 [3.227 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ERL2019-WEPNEC21

About •

paper received ※ 01 October 2019 paper accepted ※ 07 November 2019 issue date ※ 24 June 2020

Export •

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