IPAC2018 - List of Authors (Kim, D.)

Paper	Title	Page
THPAL024	A Simple Variable Focus Lens for Field Emitter Cathodes	3677
	R.L. Fleming, H.L. Andrews, K. Bishofberger, D. Kim, J.W. Lewellen, K.E. Nichols, D.Y. Shchegolkov, E.I. Simakov LANL, Los Alamos, New Mexico, USA
	Funding: Los Alamos National Laboratory LDRD Program We present the design for a simple, variable-focus solenoidal lens with integrated emittance filtering. The design was developed as a first-iteration injection optics solution for transport of a beam from a field-emitter cathode into a dielectric laser accelerator structure. The design is easy to fabricate and, while based on permanent magnets, can readily be modified to allow for remote control of the focal length. The emittance is controlled via selection of collimating irises. The focal length can be changed by altering the spacing between two permanent ring magnets. Results from fabrication and initial testing will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL024
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THPML007	An Investigation of Electron Beam Divergence from a Single DFEA Emitter Tip	4662
	H.L. Andrews, B.K. Choi, R.L. Fleming, D. Kim, J.W. Lewellen, K.E. Nichols, D.Y. Shchegolkov, E.I. Simakov LANL, Los Alamos, New Mexico, USA
	Funding: We gratefully acknowledge the support of the U.S. Department of Energy through the LANL/LDRD Program for this work. Diamond Field-Emitter Array (DFEA) cathodes are arrays of micron-scale diamond pyramids with nanometer-scale tips. DFEAs can produce high emission currents with small emittance and energy spread. At LANL, we have an ongoing program to test DFEA cathodes for the purpose of using them to generate high-current, low-emittance electron beams for dielectric laser accelerators. We have recently upgraded our cathode test chamber to use a mesh anode in place of a solid luminescent anode. In addition to allowing for downstream beam transport, this arrangement may eliminate earlier problems with reduced cathode performance due to ion back-bombardment. We are measuring divergence of the electron beam past the mesh in an effort to characterize the inherent beam divergence off the diamond tip and divergence contribution from the mesh. We will compare these observations with theoretical and modeled values.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML007
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Paper

Title

Page

A Simple Variable Focus Lens for Field Emitter Cathodes

3677

R.L. Fleming, H.L. Andrews, K. Bishofberger, D. Kim, J.W. Lewellen, K.E. Nichols, D.Y. Shchegolkov, E.I. Simakov
LANL, Los Alamos, New Mexico, USA

Funding: Los Alamos National Laboratory LDRD Program
We present the design for a simple, variable-focus solenoidal lens with integrated emittance filtering. The design was developed as a first-iteration injection optics solution for transport of a beam from a field-emitter cathode into a dielectric laser accelerator structure. The design is easy to fabricate and, while based on permanent magnets, can readily be modified to allow for remote control of the focal length. The emittance is controlled via selection of collimating irises. The focal length can be changed by altering the spacing between two permanent ring magnets. Results from fabrication and initial testing will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL024

Export •

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

THPML007

An Investigation of Electron Beam Divergence from a Single DFEA Emitter Tip

4662

H.L. Andrews, B.K. Choi, R.L. Fleming, D. Kim, J.W. Lewellen, K.E. Nichols, D.Y. Shchegolkov, E.I. Simakov
LANL, Los Alamos, New Mexico, USA

Funding: We gratefully acknowledge the support of the U.S. Department of Energy through the LANL/LDRD Program for this work.
Diamond Field-Emitter Array (DFEA) cathodes are arrays of micron-scale diamond pyramids with nanometer-scale tips. DFEAs can produce high emission currents with small emittance and energy spread. At LANL, we have an ongoing program to test DFEA cathodes for the purpose of using them to generate high-current, low-emittance electron beams for dielectric laser accelerators. We have recently upgraded our cathode test chamber to use a mesh anode in place of a solid luminescent anode. In addition to allowing for downstream beam transport, this arrangement may eliminate earlier problems with reduced cathode performance due to ion back-bombardment. We are measuring divergence of the electron beam past the mesh in an effort to characterize the inherent beam divergence off the diamond tip and divergence contribution from the mesh. We will compare these observations with theoretical and modeled values.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML007

Export •

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