IPAC2018 - List of Authors (Pierce, C. M.)

Paper	Title	Page
TUPML027	Barium Tin Oxide Ordered Photocathodes: First Measurements and Future Perspectives	1597
	A. Galdi, E. B. Lochocki, H. Paik, C.T. Parzyck, D. G. Schlom, K.M. Shen Cornell University, Ithaca, New York, USA G. Adhikari, W.A. Schroeder UIC, Chicago, Illinois, USA I.V. Bazarov, L. Cultrera, W. H. Li, J.M. Maxson, C. M. Pierce Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: This work was supported by the U.S. National Science Foundation under Award PHY-1549132, the Center for Bright Beams. Single crystalline photocathodes with small electron effective mass are supposed to enable ultra-low emittance beams, by taking advantage of the conservation of transverse (crystal) momentum. We present a preliminary study on photoemission from epitaxial films of La-doped BaSnO₃ with (100) orientation. We demonstrate here the possibility of generating and characterizing electron beams by exciting photoelectrons solely from the conduction band. We report quantum efficiency and mean transverse energy meaurements as a function of photon energy from the bare and Cs-activated La-doped BaSnO₃ surface.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML027
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TUPML028	Photocathodes R&D for High Brightness and Highly Polarized Electron Beams at Cornell University	1601
	L. Cultrera, J. Bae, A.C. Bartnik, I.V. Bazarov, R. Doane, A. Galdi, C.M. Gulliford, W. H. Li, J.M. Maxson, S.A. McBride, T.P. Moore, C. M. Pierce, C. Xu Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Cornell University is a leader in the development of photocathode materials for the production of high brightness electron beam sources for applications in large scale accelerators and small scale electron scattering experiments. During the last year we have also included Mott polarimetry to investigate long lifetime spin-polarized photocathodes materials. Another thrust of our laboratory is the exploration of ultra low emittance photocathodes at cryogenic temperatures, for which we are building a novel LHe cryogenic electron source. We will review updates from our lab across each of these areas.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML028
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THPAF024	Understanding and Compensating Emittance Diluting Effects in Highly Optimized Ultrafast Electron Diffraction Beamlines	3004
	C. M. Pierce, I.V. Bazarov, C.M. Gulliford, J.M. Maxson Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA S. Baturin Enrico Fermi Institute, University of Chicago, Chicago, Illinois, USA M.A. Gordon, Y.K. Kim University of Chicago, Chicago, Illinois, USA
	Funding: This work was supported by the Center for Bright Beams, NSF PHY-1549132 and Department of Energy grant DE-SC0014338. The application of Multiobjective Genetic Algorithm optimization (MOGA) to photoemission based ultrafast electron diffraction (UED) beamlines featuring extremely low cathode mean transverse energies has lead to designs with emittances as low as 1 nm for sub-picosecond bunches with 10⁵ electrons*. Analysis of these results shows significant emittance growth during transport: with emittance dilution as high as a factor of 200-4000% for various designs and optics settings. In this study we quantify and model the individual sources of emittance growth (slice mismatches and space charge), and explore the use of the core emittance as a strong invariant. C. Gulliford, A. Bartnik, and I. Bazarov. Multi- objective optimizations of a novel cryocooled dc gun based UED beam line. Phys. Rev. Ac- celerators and Beams, 19(9):093402, 2016.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF024
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Paper

Title

Page

Barium Tin Oxide Ordered Photocathodes: First Measurements and Future Perspectives

1597

A. Galdi, E. B. Lochocki, H. Paik, C.T. Parzyck, D. G. Schlom, K.M. Shen
Cornell University, Ithaca, New York, USA
G. Adhikari, W.A. Schroeder
UIC, Chicago, Illinois, USA
I.V. Bazarov, L. Cultrera, W. H. Li, J.M. Maxson, C. M. Pierce
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: This work was supported by the U.S. National Science Foundation under Award PHY-1549132, the Center for Bright Beams.
Single crystalline photocathodes with small electron effective mass are supposed to enable ultra-low emittance beams, by taking advantage of the conservation of transverse (crystal) momentum. We present a preliminary study on photoemission from epitaxial films of La-doped BaSnO₃ with (100) orientation. We demonstrate here the possibility of generating and characterizing electron beams by exciting photoelectrons solely from the conduction band. We report quantum efficiency and mean transverse energy meaurements as a function of photon energy from the bare and Cs-activated La-doped BaSnO₃ surface.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML027

Export •

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

TUPML028

Photocathodes R&D for High Brightness and Highly Polarized Electron Beams at Cornell University

1601

L. Cultrera, J. Bae, A.C. Bartnik, I.V. Bazarov, R. Doane, A. Galdi, C.M. Gulliford, W. H. Li, J.M. Maxson, S.A. McBride, T.P. Moore, C. M. Pierce, C. Xu
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Cornell University is a leader in the development of photocathode materials for the production of high brightness electron beam sources for applications in large scale accelerators and small scale electron scattering experiments. During the last year we have also included Mott polarimetry to investigate long lifetime spin-polarized photocathodes materials. Another thrust of our laboratory is the exploration of ultra low emittance photocathodes at cryogenic temperatures, for which we are building a novel LHe cryogenic electron source. We will review updates from our lab across each of these areas.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML028

Export •

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

THPAF024

Understanding and Compensating Emittance Diluting Effects in Highly Optimized Ultrafast Electron Diffraction Beamlines

3004

C. M. Pierce, I.V. Bazarov, C.M. Gulliford, J.M. Maxson
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
S. Baturin
Enrico Fermi Institute, University of Chicago, Chicago, Illinois, USA
M.A. Gordon, Y.K. Kim
University of Chicago, Chicago, Illinois, USA

Funding: This work was supported by the Center for Bright Beams, NSF PHY-1549132 and Department of Energy grant DE-SC0014338.
The application of Multiobjective Genetic Algorithm optimization (MOGA) to photoemission based ultrafast electron diffraction (UED) beamlines featuring extremely low cathode mean transverse energies has lead to designs with emittances as low as 1 nm for sub-picosecond bunches with 10⁵ electrons*. Analysis of these results shows significant emittance growth during transport: with emittance dilution as high as a factor of 200-4000% for various designs and optics settings. In this study we quantify and model the individual sources of emittance growth (slice mismatches and space charge), and explore the use of the core emittance as a strong invariant.
C. Gulliford, A. Bartnik, and I. Bazarov. Multi-
objective optimizations of a novel cryocooled dc gun based
UED beam line. Phys. Rev. Ac-
celerators and Beams, 19(9):093402, 2016.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF024

Export •

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