Divergence study and emittance measurements for the electron beam emitted from a diamond pyramid

Journal Article · 31 October 2019 · Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment

DOI: https://doi.org/10.1016/j.nima.2019.163055 · OSTI ID:1574002

Kim, Dongsung  ^[1]; Andrews, Heather Lynn  ^[1]; Choi, Bo Kyoung ^[2]; Fleming, Ryan Lee  ^[1]; Huang, C. -K.  ^[1]; Kwan, Thomas J. T.  ^[1]; Lewellen, IV, John W.  ^[1]; Nichols, Kimberley  ^[1]; Pavlenko, Vitaly  ^[1]; Simakov, Evgenya Ivanovna  ^[1]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. Cheju Halla Univ., Jeju-si (South Korea)

This paper reports the results of a divergence study and emittance measurements for an electron beam emitted from a single diamond pyramid in a sparse diamond field-emitter array (DFEA) cathode. DFEA cathodes are arrays of micrometer scale diamond pyramids with nanometer scale tips. A single diamond pyramid produces currents as high as 10 μA from a small surface area. DFEA cathodes are expected to be a good beam source for compact dielectric laser accelerators. For the electron beam divergence experiment, we have designed and assembled a test stand consisting of a DFEA cathode, a mesh anode, and a screen. We measured current and the size of the beam on the screen as functions of the distance between the cathode and the anode, the size of a pyramid’s base, and applied voltage on the cathode. In order to perform beam emittance measurements, we designed and fabricated a magnetic lens to be placed between the mesh and the screen. By measuring the size of the beam for different distances between the lens and the screen, we estimate the beam’s emittance. Here, we also simulated the electron beam dynamics with Computer Simulation Technology Studio and General Particle Tracer codes. Experimentally measured divergence angles and normalized transverse emittance show good agreement with simulations.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE Laboratory Directed Research and Development (LDRD) Program
• Grant/Contract Number: 89233218CNA000001
• OSTI ID: 1574002
• Alternate ID(s): OSTI ID: 1702596
• Report Number(s): LA-UR-19-30904; TRN: US2001440
• Journal Information: Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 953, Issue C; ISSN 0168-9002
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
Accelerator Design, Technology, and Operations
Diamond field-emitter array
Cathode
Divergence
Emittance