J. Andrew Spencer, PhD
Andrew Spencer
I’m a computational physicist. I spent thirteen years building and testing the numerical methods behind plasma simulations, and I now bring that same care to custom software, technical writing, and creative projects.
This field is live. About 3,000 scattered points and no mesh — the kind of point cloud my 2025 wave solver works on. Move your cursor or use the ← → keys to steer the antenna; click to launch a pulse.Tilt your phone or drag to steer the antenna; tap to launch a pulse. An illustration, not a physics solution.
The point cloud. Each point builds its derivatives from a 13-point “star”: itself plus its three nearest neighbours in each of four sectors, the stencil used in my 2025 paper. Points pack densely along the resonance, where the waves get short. Hover to move the star.Tap to move the star.
Selected work
Each card opens the full story: what the problem was, what I built, and where to read more.
How I can help
I take on independent projects, large and small. Currently taking on new work.
Scientific computing
Numerical methods, solvers and research code in Fortran, C++ and Python, from first prototype to verified, parallel runs.
Custom tools and automation
Small web apps and pipelines that take repetitive work off your plate, built to be dependable and easy to hand over.
Technical writing and explanation
Documentation, explainers and teaching material that make hard ideas clear, for students, clients or specialists.
Scripts and digital media
Scripts and story-driven content for video and social, with AI-assisted production where it genuinely helps.
Publications
Fourteen papers from 2011 to 2025 and my dissertation, on collision operators, kinetic closures and radio-frequency waves, plus an early excursion into the geometry of time. Download BibTeX
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2025
An implementation of a high-order generalized finite difference method for solving the time-harmonic cold plasma wave equation in toroidal geometry
Physics of Plasmas 32, 063902First authorOpen access
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2025
An analysis and successful benchmarking of the Chapman-Enskog-like (CEL) continuum kinetic closure approach algorithm in NIMROD
Computer Physics Communications 306, 109382
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2023
Moment-Fourier approach to ion parallel fluid closures and transport for a toroidally confined plasma
Plasma Physics and Controlled Fusion 65, 035018
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2022
Accurate numerical, integral methods for computing drift-kinetic Trubnikov-Rosenbluth potentials
Journal of Computational Physics 450, 110862First author
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2021
Benchmarking NIMROD continuum kinetic formulations through the steady-state poloidal flow
Physics of Plasmas 28, 082503
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2021
Potential, field, and interactions of multipole spheres: Coated spherical magnets
Journal of Magnetism and Magnetic Materials 529, 167861
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2020
Exact irreducible moments of the Landau collision operator in the random-velocity moment expansion
Plasma Research Express 2
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2018
Hybrid iterative approach for simulation of radio-frequency fields in plasma
Physics of Plasmas 25, 082509
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2016
Hot plasma dielectric response to radio-frequency fields in inhomogeneous magnetic field
Physics of Plasmas 23, 112101
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2015
Electron-beam-ion-source (EBIS) modeling progress at FAR-TECH, Inc.
AIP Conference Proceedings 1640, 44
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2014
Modeling multiple-frequency electron cyclotron resonance heating
Review of Scientific Instruments 85, 02A914First author
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2014
Analytical and numerical modeling of radio frequency electron cyclotron resonance power absorption within the cold plasma picture
Review of Scientific Instruments 85, 02A503
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2012
A finite element/Fourier treatment of the Fokker-Planck equation
Journal of Computational Physics 231, 6192First author
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2012
A 2D finite element/1D Fourier solution to the Fokker-Planck equation
PhD dissertation, Utah State UniversityFirst authorDissertationOpen access
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2011
The existence of time
International Journal of Geometric Methods in Modern Physics 8, 273–301
Authors listed alphabetically, following the convention in mathematical physics.
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About
I earned my PhD in physics at Utah State University in 2012, with a dissertation on a finite-element and Fourier solver for the Fokker–Planck equation. My advisor was Eric Held.
Most of my career has been on the numerical side of plasma physics. At FAR-TECH, Inc. I modeled ion sources and radio-frequency heating. Back at Utah State, as a research scientist, I developed kinetic physics and solvers for the NIMROD code and was a co-PI on a SciDAC project for tokamak edge optimization.
Today I work independently. I take on scientific computing, custom web tools and automation, and technical writing, and I’m building a practice in scripts and digital media.
- 2025–nowIndependent consultantCreative-studio and research clients, including FAR-TECH, Inc. (2025–2026)
- 2017–2025Research scientistUtah State University
- 2012–2017Staff scientistFAR-TECH, Inc.
- 2012PhD, physicsUtah State University; earlier BS degrees in mathematics (magna cum laude) and physics (summa cum laude)
- Languages
- Fortran, Python, C++
- Parallel computing
- MPI, OpenMP, GPUs, Slurm, Spack
- Numerical libraries
- PETSc, SuperLU, MUMPS
- Methods
- Finite elements, meshless finite differences, particle-in-cell, moment expansions, implicit schemes