Z-pinch — the current is the confinement
A linear plasma column confined by the azimuthal magnetic field of its own axial current, with sheared axial flow as the stabilising variant. SCPN-Z-PINCH-CORE owns the device truth of the Z-pinch configurations, the classical static column and its sheared-flow class.
What the configuration is
The Z-pinch is the oldest fusion idea: pass a large current along a column of plasma and the magnetic field the current makes squeezes the column. Bennett wrote its equilibrium in 1934; Kruskal, Shafranov and Kadomtsev showed why the static column tears itself apart on the Alfvén time through sausage and kink modes. Two ideas keep the family alive — a sheared axial flow that Shumlak and Hartman showed stabilises the modes above a threshold, and the radiative collapse above the Pease–Braginskii current that makes the pinch a radiation source before it is a reactor.
What the core owns
- the analytic device physics models: closed-form and 0-D models from the z-pinch literature evaluated on the validated configuration (no solver code, no FUSION seam);
- the device geometry and its 3D model: the coaxial mechanical envelope (electrodes, acceleration and assembly regions, chamber, end walls), the analytic-surface model and the tier-G2 B-rep CAD model with a normalised deterministic STEP export;
- the device boundary: plant and experiment truth, shot lifecycle and configuration policy for linear columns confined by their own azimuthal field, including the Bennett-type pressure balance, the sausage/kink instability structure and sheared-axial-flow stabilisation as the family's second registry configuration;
- the declared configuration: column radius and length; peak current and ion line density; pulsed-power driver semantics (capacitor banks, pulse lines, electrode assemblies) as configuration facets;
- 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
- Theta pinch (azimuthal induced current, axial field compression): SCPN-THETA-PINCH-CORE; dense plasma focus (coaxial-gun rundown and focus dynamics): SCPN-DENSE-PLASMA-FOCUS-CORE.
- Magnetised liner inertial fusion (MagLIF-class premagnetised, preheated liner implosion): SCPN-MIF-MAGLIF-CORE; reversed-field pinch (toroidal relaxed-state confinement): SCPN-RFP-CORE.
- 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 Bennett equilibrium (Bennett 1934; Haines 2011 §2): the integral pressure balance, the Bennett density and pressure profiles, the azimuthal field of that profile, the enclosed current, and the Alfvén speed and transit time at the on-axis density; tests close the balance to machine precision, integrate the profile back to the line density, verify Ampère's law at sampled radii and check the \(I^2\), \(1/N\) and \(m_i^{-1/2}\) scalings. Ideal-MHD estimates (Haines 2011 §5; Kadomtsev 1966): \(\gamma \sim k v_A\) for a declared wavenumber and the \(m = 0\) criterion on the Bennett profile in closed form, reproducing the published conclusion that the profile is sausage-unstable at every radius for \(\gamma_{\mathrm{ad}} = 5/3\) and that the reduced criterion flips exactly at \(\gamma_{\mathrm{ad}} = 2\). Sheared-flow stabilisation (Shumlak & Hartman 1995): the threshold \(0.1\,k v_A\) and the disposition of the declared shear; the static class reports no stabilisation. The Pease–Braginskii current in Klíř's closed form (eq. 2.20) with the NRL Formulary coefficients in SI: 1.37 MA against the literature's ≈ 1.4 MA at \(\ln\Lambda = 10\).
Load the hydrogenic column at the Pease–Braginskii current in the explorer →
Non-claims
- Every number is a closed-form evaluation of a cited published model on a synthetic configuration; no equilibrium, stability or transport equation is solved, and no linear eigenvalue problem exists.
- No reactivity, yield, gain, breakeven or confinement-time statement is made; the Pease–Braginskii regime label is an energy-balance disposition of the cited model, not a prediction.
- No value describes, approximates or validates any real machine; the benchmark measures per-point evaluation cost, not physics. Electrode-geometry, driver-class and fuel-cycle choices are configuration facets, not separate claims.
Capabilities and evidence
Evidence maturity computational_prototype, five implemented capabilities, each with its evidence record in VALIDATION.md: the device configuration model, the diagnostic and clock semantics model, level-0 device physics (the closed forms on this page, with a Rust crate mirroring every kernel in identical operation order, float64 bit patterns compared, and a per-point evaluation benchmark), the device 3D model and the device CAD model. No parameter set or channel describes any real machine or diagnostic.