Atom Probe Tomography (APT) L1-128
Unclaimed Principle — open for contribution
This Principle is declared in the catalog but has no reference solver, no pinned dataset, and is not registered on-chain. There is no reward pool. Submitting a cert against this Principle today will record the cert for reproducibility but pay zero PWM.
To claim it as a Bounty #7 contribution: open a PR adding (1) a reference solver, (2) ≥1 dataset pinned to IPFS, (3) updates to the L3 manifest with dataset CIDs. After verifier-agent triple-review, the founders' 3-of-5 multisig signs PWMRegistry.register() and the Principle becomes mineable.
Forward model E
A needle-shaped sample (apex radius 30-100 nm) is cooled (30-80 K) and biased to high voltage; a laser or voltage pulse triggers field-evaporation of surface ions one at a time. A position-sensitive time-of-flight detector records (x,y,t); x,y maps to 3D atom position, t to m/z. Reconstruction yields atom-by-atom chemical composition with ~0.2 nm spatial resolution.
L-DAG
Well-posedness W
- Existence:
- true
- Uniqueness:
- element ID unique from m/z; spatial position subject to trajectory-model assumptions
- Stability:
- conditional
- κ:
- 1000
Reconstruction is ill-posed due to hemispherical projection approximation — fails at multi-phase tips (different evaporation fields per phase). Field-ion trajectories assumed ideal; local magnification errors of 10-30% at interfaces.
Solvability C
- Solver class:
- IVAS/APSuite point-projection reconstruction, direct field-density, posterior-sampling (Wei et al.), learned (APT-Net), FIM-assisted priors
- Convergence rate q:
- 2
- Complexity:
- IVAS O(N_events * log); ML priors iterative