Magnetic mirror — the magnetic bottle
Open-field-line linear devices confined axially by magnetic mirror forces: the single-cell mirror governed by its loss cone, the tandem mirror with electrostatic end plugs, and the gas-dynamic mirror in the high-collisionality regime. SCPN-MIRROR-CORE owns the device truth of the simple_magnetic_mirror, tandem_mirror and gas_dynamic_mirror configurations.
What the configuration is
A magnetic mirror is a straight solenoid whose field is stronger at both ends: particles spiralling toward an end are reflected by the rising field unless their velocity is too nearly parallel to it, and those escape through the loss cone. The simple mirror therefore leaks, on the ion–ion scattering time, the fraction of its ions that scatter into the cone. The tandem mirror plugs the ends electrostatically with denser end cells; the gas-dynamic mirror accepts a collisional plasma and confines it for the time a sound wave takes to traverse the cell, times the mirror ratio. Axisymmetric high-field mirrors, the subject of the WHAM physics basis the core anchors on, rely on finite-Larmor-radius effects and sheared flow for the interchange stability the axisymmetric field cannot provide by itself.
What the core owns
- the device geometry and its 3D and CAD models: the mechanical envelope of the assembly and the ten bodies derived from it at both tiers, on the shared geometry and CAD kernels;
- the analytic device physics models: closed-form and 0-D models from the mirror literature evaluated on the validated configuration (no solver code, no FUSION seam); the transcendental kernels are the shared library's, pinned here;
- the device boundary: plant and experiment truth, lifecycle and configuration policy for the single-cell, tandem and gas-dynamic mirror; axial-confinement semantics — loss-cone population, end-plug and thermal-barrier potential declarations, expander and end-tank boundary conditions;
- the declared configuration: throat and midplane field; central-cell length and end-plug cell count;
- 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
- Magnetic cusp confinement: SCPN-MAGNETIC-CUSP-CORE; electrostatic confinement (gridded IEC and Polywell-style devices): SCPN-IEC-CORE; levitated dipole: SCPN-LEVITATED-DIPOLE-CORE; toroidal systems: the closed-field cores.
- 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
Mirror ratio and loss boundary (Endrizzi eq. 3.6, Frank eqs. 2.3–2.5); collisional time-scales (eqs. 3.1–3.3) with the engineering forms at unit inputs (5 ms, 1/8 ms, 5.8 µs) and the identity \(\tau_s = \tau_{ii}\) at \(T_e = E_i/40^{2/3}\); confinement scalings (eqs. 3.4–3.5) with the 250 ms reference point, the exact "only 50 %" gain from beta, and the gas-dynamic coefficient 5.2 within 3 %; the FLR criterion (eq. 3.7) with the worked case \(m_{\mathrm{crit}} = 0.8\); adiabaticity (§3.6) with the threshold 10; tandem confinement (Frank eqs. 3.2–3.7, 4.3) with \(G(1) = \sqrt2\ln(3 + 2\sqrt2)\). Numerics through the pinned shared kernel library; a Rust crate mirrors every kernel with float64 bit patterns compared over a 72-point grid.
Anchored on two CC BY 4.0 papers: Endrizzi et al., Physics basis for the Wisconsin HTS Axisymmetric Mirror (WHAM), J. Plasma Phys. 89 (2023); Frank et al., Confinement performance predictions for a high field axisymmetric tandem mirror, J. Plasma Phys. 91 (2025). The typography of the printed eq. 2.5b is resolved by the source's own statement (ADR 0005 item 3). No printed numerical anchor exists for eq. 3.3 or for adiabaticity; those records are pinned as immutability fixtures.
Load the mirror fixture in the explorer →
Non-claims
- Every number is a closed-form evaluation of published scalings on a synthetic configuration; no Fokker–Planck, ambipolar, equilibrium or stability equation is solved.
- The anchors reproduce numbers and statements printed in the sources; they are not correlations with experimental data; the gas-dynamic coefficient is matched only to the stated 3 %.
- No fusion power, gain, breakeven, reactivity or \(m = 1\) stability statement is made; the plug electron potential and the field-gradient scale length are declared inputs, not results.
- No value describes, approximates or validates any real machine; cell-count, plugging-scheme 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), the device 3D model and the device CAD model. No parameter set or channel describes any real machine or diagnostic.