Calculate charged-particle stopping powers (dE/dx) and CSDA ranges directly in the browser — no installation required. Select a particle, a target material, and an energy range; get numerical results and interactive plots instantly. Based on the libdedx library, running fully client-side via WebAssembly.
Open beta candidate — Stage 7 complete; Stage 8 user-feedback cycle active. Deployed continuously from master.
Last stable release — fully functional but based on the old React stack. Released 1 April 2022.
v1.1.0 (April 2022) has several limitations: no unit handling, React 17 class components with no TypeScript, and plots that do not meet the needs of typical physics workflows.
v2 is a ground-up rewrite addressing all of the above. It is also an experiment in AI-assisted (vibe-coded) development — the codebase is written by AI agents (GitHub Copilot, Claude Code, opencode) guided by spec-driven prompts, with human review. Stage 7 (E2E tests, UI polish, WASM error handling, and external .webdedx data) is complete; the app is now entering Stage 8 open beta and user feedback. v2.0.0 will replace the stable site on first production release.
- PSTAR (NIST) — proton stopping powers
- ATIMA — similar scope, different library
Prerequisites: Docker (for the WASM build), Node.js 24+, pnpm.
Build the WASM module (requires Docker; pulls emscripten/emsdk:5.0.5, ~2 min on first run):
(cd wasm && ./build.sh)Install dependencies and start the dev server:
pnpm install && pnpm devOpen http://localhost:5173.
Full technical documentation — architecture, WASM API, build pipeline, testing strategy, and developer guides — is available at:
aptg.github.io/web_dev/docs/technical
v1 was developed by Piotr Połeć and Marek Ślązak under supervision of Leszek Grzanka.
v2 is led by Leszek Grzanka with AI assistants (GitHub Copilot, Claude Code, opencode).