A friendly front end for serious plasma physics.
JC-PIC is a 1D3V Particle-In-Cell / Monte Carlo Collision code for low-pressure, weakly ionized plasmas — the discharges of plasma processing and gaseous electronics.
Set up a discharge, click Run, and watch the plasma evolve through a dozen live viewers. No code to write. A validated Fortran engine behind a friendly interface — and it's completely free.
Windows desktop · No account, no telemetry, no internet required · Bundled with a library of ready-to-run cases
Particle-In-Cell / Monte Carlo Collision (PIC-MCC) solvers have been used extensively over the last two decades to study the physics of low-temperature plasmas. Thanks to these kinetic models, many complex phenomena central to practical plasma applications — electron power absorption in capacitively and inductively coupled discharges, instabilities in the magnetized plasmas of electric thrusters and magnetrons, the influence of secondary electron emission on wall sheaths and plasma potential, pattern formation and striations in plasma columns, and more — are now far better understood.
JC-PIC was built with three goals in mind:
Revisit the physics of low-temperature plasmas through the lens of the PIC-MCC simulations published over recent years — reproducing and summarizing the key conclusions of many of these papers (here, in one dimension).
Offer a fully user-friendly PIC-MCC code, usable by anyone — including non-experts in modelling: experimentalists, students, researchers and teachers — to reproduce and understand a large body of published results, with no programming required.
Meet the challenge of developing the code and its unusually complete graphical interface entirely with the help of Anthropic's Claude AI — the route that made a tool of this scope feasible at all.
The physics is the well-established PIC-MCC method, shared with many codes. What's unusual is the door built around it — and the way that door came to exist.
JC-PIC is meant for everyone — students meeting kinetic plasmas for the first time, experimentalists with no simulation background, and researchers reproducing a published result. They can also pursue their own studies and have them folded into the bundled test cases, shared with the whole community — so JC-PIC can grow into a genuinely collaborative tool. A graphical, tabbed interface asks for no programming at all. The same physics the pioneers taught; the door simply made wider.
An interface this complete — a tabbed dialog over dozens of parameters, a curated case browser, a dozen viewers, persistent state — would normally cost a scientist many months of tedious work. JC-PIC was instead written almost entirely by Anthropic's Claude Opus under the scientific direction of the author — sitting on top of a modern Fortran engine parallelized with OpenMP. The power of the tool and the way it was built are inseparable.
One spatial dimension, three velocity components, electrostatic fields with an external magnetic field, and Monte Carlo collisions with the neutral gas — covering a broad range of low-temperature discharge configurations. Each ships as a ready-to-run, openly extensible bundled case: pick one close to your problem, reproduce it, then vary the parameters from there.
Single- and multi-frequency capacitively coupled plasmas driven by prescribed voltage waveforms, including the dual-frequency electrical asymmetry effect and electron power-absorption analysis.
Direct-current glow discharges with secondary emission, with or without a superimposed RF component, plus pulsed plasma-immersion ion implantation with fast sheath expansion.
The axial structure of a long discharge in periodic mode: ionization waves (striations) in DC and RF columns, radial non-equilibrium, and the Hall effect.
A weak external magnetic field, and Hall-thruster-style azimuthal E×B configurations exhibiting the electron-cyclotron drift instability.
Space-charge-limited current (Child–Langmuir), virtual-cathode oscillations, thermionic emission and self-sustained thermionic discharge regimes.
The classic two-stream, Buneman and beam–plasma instabilities in their cleanest periodic form.
Secondary electron emission, cathode emission (cold, beam, thermionic), and full electron & ion Monte Carlo collisions (elastic, excitation, ionization, charge exchange) are all built in, using cross-section tables loaded at startup.
Most cases ship with a precomputed snapshot, so you can visualize them the moment they load — and the library is collaborative and extensible: a case you build can later be folded into the shared library for the whole community.
Everything is organized so you interact with the plasma the way you would with a piece of laboratory hardware.
Dozens of physical and numerical parameters — gas, pressure, voltages, frequency, fields, diagnostics — organized into intuitive categories instead of a cryptic input file.
Walk a tree of preconfigured cases, read its Markdown description, and load it into your own working directory in one click. The recommended entry point.
Density profiles, position–time diagrams, phase space, EEPF (1D & 2D), ion/electron energy distributions, current histories, the Schulze power decomposition, and more.
Results are written to disk continuously and survive restarts. Pause, stop, and resume a run at any later time — even on another machine pointing to the same folder.
The simulation core is modern Fortran parallelized with OpenMP, automatically using every core. A typical capacitive-RF case runs in a few hours on an ordinary desktop.
No cloud, no telemetry, no account. Plain-text namelists, Markdown descriptions, JSON metadata and documented binary snapshots — your data stays fully accessible.
The friendly interface delivers physics that is quantitatively correct, not merely plausible.
Cross-checked against J-PIC, the author's own earlier particle-in-cell code, used and verified in several published studies.
Reproduces the four-case capacitively-coupled RF benchmark of Turner et al. (Phys. Plasmas, 2013) — the reference test every modern low-temperature PIC code is expected to pass.
Reproduces a large body of published PIC-MCC results — emissive cathodes, DC and RF discharges, striations, magnetized E×B plasmas and beam instabilities — most of them bundled and ready to run.
Phase-space and profile animations exported straight from JC-PIC's diagnostic viewers — each from a bundled case you can load and reproduce.
Counter-streaming beams wind phase space into cat's-eye vortices.
A beam above the space-charge limit traps and reflects electrons.
A dilute fast beam destabilizes against a dense background.
JC-PIC has the unusual distinction of having been written, in its entirety, by an artificial intelligence — Anthropic's Claude Opus (versions 4.7 and 4.8 as the models evolved) — working under the scientific direction of the author.
The Fortran/OpenMP engine, the Python/Tkinter interface, the dozen viewers, the case browser, the build pipeline and even the user manual were produced from natural-language specifications. The human contribution stayed focused on the physics requirements, the validation against benchmarks, and the iterative refinement of the user experience.
Months of development effort were compressed into a few weeks — and the physics itself (the Boris pusher, the null-collision MCC algorithm, the Poisson solver, the secondary-emission model) was implemented accurately, close to its final form on the first attempt.
This approach extends beyond plasma physics: with the same AI-assisted method, the author also built LibrAIry ↗, a desktop reference manager and private AI assistant for organizing and analyzing scientific PDFs.
A complete walkthrough — from loading a bundled case to running it and reading the diagnostics in the viewers.
The walkthrough video will be embedded here. Replace this placeholder with the YouTube / archive.org embed once recorded.
A single installer bundles the simulation engine, the graphical interface, the cross-section data files and the full test-case library. No administrator privileges needed.
New to JC-PIC? See the quick-start steps just below.
From a fresh install to a running plasma in four steps. The bundled case library is the recommended entry point — no blank configuration to fill in.
Run the installer, open JC-PIC, and choose a working folder where your runs will live. Each simulation is just a self-contained folder on your disk.
Open Input → Load Test Cases…, browse the library, and pick a case close to what you have in mind. JC-PIC copies it into your working folder.
Click Run to start from t = 0, or open the bundled snapshot for an instant quasi-steady view. Results are written to disk as it goes.
Open the live viewers — density profiles, phase space, EEPF, wall fluxes — then vary the pressure, voltage, frequency or field and see how the discharge responds.
A paused or stopped run can be resumed at any later time — even on another machine pointing to the same folder. The full procedure is covered in the user manual.
