NeXus Viewer

A browser app for exploring 3-D neutron and X-ray scattering volumes: reciprocal-space slices, line cuts and I(Q) of reduced data, with nothing to install and files that never leave your machine.

What it does

• Slices and line cuts of Mantid MDHistoWorkspace, NXdata and NEBULA3D files, drawn in the true lattice geometry, with nothing smoothed or interpolated.
• Symmetry averaging and artifact masks, applied exactly on the bin grid, with a check that the operations fit the cell.
• Up to four datasets compared (temperatures, or X-ray next to neutron), with I(Q) and a 3-D view.
• UB refinement against the volume's Bragg peaks, with the cell constrained to a crystal system, reindexing with a new UB (a resampling, which smooths), and reduction of raw Rigaku XRD frames to an HKL volume.
• Hand-off to NEBULA3D for a 3D-ΔPDF.

Quick start

Open drthyang.github.io/neutron-nexus-viewer and drop a .nxs file on the page, or open the example, a synthetic hexagonal crystal at 300 K and 10 K. To run it locally, serve the folder (python3 -m http.server 8000). A first session, step by step, is in Features.

Agent tools

npm install && npm run mcp serves the analysis to AI agents as 10 MCP tools (Claude Code, Claude Desktop, any MCP client), computed by the viewer's own code. The tool list and setup are in docs/AGENT.md; scattering-agent-tools installs them together with the other apps' tools.

Status

No tagged releases yet: the live app is deployed from main on every push, and CI runs the tests, which check the slice engine against the reference Python implementation, on every push.

Documentation

• Features: the goals, everything the viewer does, and a first session
• User guide: every control, supported files, comparison, reindexing, Rigaku reduction, export
• Method: how each result is computed, and how it is validated
• Agent tools: the MCP server, its tools and their conventions
• Development: code layout, tests and fixtures, dependencies, deployment

License

GNU Affero General Public License v3.0 © 2026 Tsung-Han Yang. If you run a modified version on a network server, you must make its complete source available to its users (AGPL §13).

This project is personal work, developed and maintained in my personal capacity.