Result archives

Result.save_to_disk("case.morana-result") writes a portable result archive; Result.load_from_disk(...) restores it as a new, checked Result. The format retains a completed calculation for later inspection, plotting, export, or provenance review.

The conventional suffix is .morana-result, but save and load use the exact path supplied by the caller. Thus result.save_to_disk("case") writes an archive named exactly case; the manifest, rather than the filename, identifies the format. The maintained result_archive.py example demonstrates a round trip.

Contents and compatibility

An archive is a standard DEFLATE-compressed ZIP container containing an explicit UTF-8 JSON manifest and named NumPy .npy payloads. It records flux and typed balance diagnostics, configuration provenance, tagged mode-specific solve settings, and the typed execution report. A criticality archive always records one physical normalization: either a fission-source rate or recoverable power. Fixed-source archives have no normalization. Configuration provenance retains whether each material uses the compact null or explicit-array scattering-multiplicity representation, along with its fission data. Fission data are null for a nonfissile material; otherwise their neutron_production object is explicitly tagged separable or transfer. A separable record retains nu_sigma_f, chi, and its normalization tolerance, while a transfer record retains only the canonical event-oriented fission_transfer[g_from, g_to] array. Thus an archive restores the representation the caller selected instead of converting it to a flattened or alternate form. solve_mode is derived from the retained values when the result is reconstructed; it is not stored separately.

Archives use pre-release schema version 8, which has no backward-compatibility guarantee. Readers accept only this representation and reject every other schema version or malformed tagged record.

Integrity and consistency checks

Payloads are loaded with allow_pickle=False. The manifest records every payload’s name, shape, dtype, and SHA-256 checksum. The loader checks the ZIP member list before reconstruction, verifies payloads as they are read, and rejects unreferenced payloads before returning the result. Duplicate, encrypted, missing, unexpected, and checksum-mismatched members are rejected, as are members with unsafe paths.

Stored flux must be finite and nonnegative, and its energy-group count must match the active materials in the retained configuration. Criticality reports must satisfy their recorded outer-iteration limit and final convergence tolerances, in addition to the linear residual checks.

When completing or loading a criticality result, Morana recomputes the declared physical normalization from the retained flux and configuration snapshot. A fission-source target must agree with the integrated fission-production response within a relative tolerance of 1e-10 (with zero absolute tolerance). A power target must meet the same tolerance against the integrated kappa_sigma_f * flux response after conversion from eV/s to W, and every fissionable active material must retain kappa_sigma_f. A mismatch is rejected. Loading checks the stored result’s structure and normalization; it does not rerun the solve or independently recompute every stored balance or execution-report value.

The restored result owns fresh read-only arrays and a configuration snapshot. It can therefore be plotted or exported in the same way as an in-memory solve; see inspection and output for those artifacts and modeling and solver workflow for result interpretation.