IEC and polywell — a well deep enough to fuse
Devices whose reaction workflow is an electrostatic potential well accelerating and recirculating ions toward a dense core: the gridded fusor with its transparent cathode grid, and the polywell with a virtual cathode formed by electrons injected into a magnetic-cusp trap. SCPN-IEC-CORE owns the device truth of the gridded_iec and polywell configurations.
What the configuration is
Hirsch built the first inertial-electrostatic fusors in 1967: a spherical wire cathode inside a spherical anode, a potential well of tens of kilovolts, ions falling to the centre and passing through to the far side again and again. The grid is the device's limit — every pass risks a wire — and the polywell's answer is to make the cathode out of electrons held in a magnetic cusp so that nothing solid stands in the ions' way. The registry files the polywell under the open-magnetic family for its cusp topology; the portfolio standard assigns it here because what it does with energy and reactions is an electrostatic well. The core carries the grid's geometry, the one part of the device a filed open-access source prints in closed form.
What the core owns
- the device boundary: plant and experiment truth, lifecycle and configuration policy for gridded fusors and polywells;
- potential-well and recirculation semantics as device truth: well-depth declarations, grid-transparency or electron-confinement budgets, core-convergence declarations, continuous-discharge operation facets;
- the declared configuration: confinement kind, cathode grid transparency, polyhedral coil count; well voltage;
- diagnostic semantics, reference frames and clock identity declarations; the CONTROL adapter specification; the registry binding (version 1.0.0) and the domain manifest.
What it explicitly excludes
- Purely magnetic cusp confinement: SCPN-MAGNETIC-CUSP-CORE; magnetic mirrors: SCPN-MIRROR-CORE; beam-target fusion with externally accelerated beams: SCPN-BEAM-TARGET-CORE — the IEC's recirculating-ion reactions are device truth here.
- Solver mathematics and validation evidence: SCPN-Fusion-Core, until an exact surface passes the reactor family migration gate; no solver code exists in, or was copied into, the device core.
- Typed signal semantics and comparability: SCPN-Phase-Orchestrator (review-only output, never actuation). Control admission and action formation: SCPN-Control. Machine protection: independent systems retain the final veto. Portfolio presentation and gating: SCPN-Studio.
Level-0 physics and its anchor
The closed-form geometry of a spherical cathode grid as Wulfkühler et al. (Scientific Reports, 2024, open access) print it: the bridge half-angle \(\arctan(t/D)\), the globe-grid aperture count \(2n_{\mathrm{long}}(n_{\mathrm{lat}}+1)\), the four permissible symmetric grids with the crossing rule \(360^\circ/2n\), the geometric transparency as aperture area over sphere area, the circular transparency of the largest circles the apertures admit, and their ratio; the pass-count bound \(\eta/(1-\eta^2)\), refused outside \((0,1)\); a composed record that requires a grid declaration for the gridded class and refuses one for the polywell, and that recomputes the geometric transparency beside the declared one without deriving either from the other. Anchors: all four printed bridge angles to three decimals; the 50 apertures of Figure 11; both endpoints of the 8-to-220 family; every row of the symmetric-grid table, two of them corroborated from other laboratories; the nine-ring cathode Radel (UWFDM-1325, 2007) reports as built and operated at Wisconsin, giving the 48 apertures the other source tabulates. Measured: the bridge-angle table cannot settle the arctangent in its own equation; the pass-count denominator is evaluated factored; composed and single-step transparency forms agree to \(8.4\times10^{-15}\); a spherical cap whose base is the sphere radius falls one ulp below half the sphere because \(\cos(\arcsin 1)\) is not zero.
Build the Wisconsin cathode in the explorer →
Non-claims
- No value describes, approximates or validates any real machine; an anchor reproduces a number a filed source prints and nothing further.
- The pass-count bound rests on transparency alone: it sees no pressure, charge exchange, scattering or ion energy, and the source states most devices operate where an ion makes only a few passes. It is an upper bound set by geometry, never a predicted pass count.
- Aperture areas and neighbour half-angles are declared inputs measured off a grid model the repository does not build; the polywell's virtual cathode is a declaration, not a field calculation; no magnetic geometry is computed.
- No fusion rate, neutron yield, sheath, space-charge or transport result is computed; grid-geometry, electron-injection and fuel choices (including aneutronic ambitions) are configuration facets, not separate claims.
Capabilities and evidence
Evidence maturity computational_prototype, three implemented capabilities, each with its evidence record in VALIDATION.md: the device configuration model, the diagnostic and clock semantics model and level-0 device physics (the closed forms on this page). No parameter set or channel describes any real machine or diagnostic.