Author: Hall, C.C.
Paper Title Page
SUPAF07 High-Fidelity Three-Dimensional Simulations of Thermionic Energy Converters 59
 
  • N.M. Cook, J.P. Edelen, C.C. Hall, M.V. Keilman, P. Moeller, R. Nagler
    RadiaSoft LLC, Boulder, Colorado, USA
  • J.-L. Vay
    LBNL, Berkeley, California, USA
 
  Funding: This work is supported the US DOE Office of Science, Office of High Energy Physics: DE-SC0017162.
Thermionic energy converters (TEC) are a class of thermoelectric devices, which promise improvements to the efficiency and cost of both small- and large-scale electricity generation. A TEC is comprised of a narrowly-separated thermionic emitter and an anode. Simple structures are often space-charge limited as operating temperatures produce currents exceeding the Child-Langmuir limit. We present results from 3D simulations of these devices using the particle-in-cell code Warp, developed at Lawrence Berkeley National Lab. We demonstrate improvements to the Warp code permitting high fidelity simulations of complex device geometries. These improvements include modeling of non-conformal geometries using mesh refinement and cut-cells with a dielectric solver. We also consider self-consistent effects to model Schottky emission near the space-charge limit for arrays of shaped emitters. The efficiency of these devices is computed by modeling distinct loss channels, including kinetic losses, radiative losses, and dielectric charging. We demonstrate many of these features within an open-source, browser-based interface for running 3D electrostatic simulations with Warp, including design and analysis tools, as well as streamlined submission to HPC centers.
 
slides icon Slides SUPAF07 [6.097 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-ICAP2018-SUPAF07  
About • paper received ※ 01 November 2018       paper accepted ※ 19 November 2018       issue date ※ 26 January 2019  
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WEPAF03
Magnetized Electron Cooling Simulations for JLEIC  
 
  • I.V. Pogorelov, D.T. Abell, D.L. Bruhwiler, J.A. Carlsson, Y.I. Eidelman, C.C. Hall, S.D. Webb
    RadiaSoft LLC, Boulder, Colorado, USA
  • J. Gerity, P.M. McIntyre
    Texas A&M University, College Station, USA
  • H. Zhang, Y. Zhang
    JLab, Newport News, Virginia, USA
 
  Funding: This work is supported by the U.S. DOE Office of Science, Office of Nuclear Physics, under Award Number DE-SC0015212.
Relativistic magnetized electron cooling in untested parameter regimes is essential to achieve the ion luminosity requirements of proposed electron-ion collider (EIC) designs. Therefore, accurate calculations of magnetized dynamic friction are required, with the ability to include all relevant physics that might increase the cooling time, including space charge forces, field errors and complicated phase space distributions of imperfectly magnetized electron beams. We present simulations relevant to the JLEIC design, using the BETACOOL and JSPEC codes. We also present recent work on Warp simulations of the electron beam through the solenoid field. Space charge neutralization is provided by impact ionization of a background hydrogen gas. For optimal cooling it is essential that space charge be sufficiently neutralized. We also present recent work on a new analytic treatment of momentum transfer from a single magnetized electron to a drifting ion, and its use for calculations of dynamic friction.
 
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