The 3D engine renders the plasma as a full instanced-particle volume you orbit around. This 2D companion solves the identical energy-balance physics independently and instead shows the true axisymmetric side-view cross-section — the natural 2D projection of a device that is symmetric about its axis — plus a second panel most 3D views can't show clearly: the live thrust/Isp trade-off curve.
v_e = √(2 · η_nozzle · P_ICH / ṁ)
F = ṁ · v_e
Isp = v_e / g₀
η = (½ · ṁ · v_e²) / P_total
η_nozzle = 0.55 + 0.35·(1 − e^(−B/0.4))
Verified against the 3D engine's own formulas (same constants, same functional forms) — no discrepancy found, so this build keeps the identical rate law rather than an approximation. Raising the ICH power split sends more of the fixed total power into ion heating instead of ionization, raising exhaust velocity and Isp at fixed mass flow. Raising the magnetic field strengthens the magnetic-mirror conversion η_nozzle, reclaiming more perpendicular ion energy as directed thrust. Raising mass flow at fixed power trades Isp for thrust — the same lever real VASIMR concepts (Ad Astra VX-200) use to fly high-Isp cruise legs and high-thrust burns on one engine.
- Cross-section view — ions drift left→right through the helicon source, ICH heater and diverging magnetic nozzle; their vertical spread is the true perpendicular (gyration) radius, not a decorative wobble.
- Trade-off curve — sweeps the ICH split from 30–90% at your current power/flow/field and plots the resulting Isp vs thrust family; the dot is your exact operating point.
- Drag to pan, scroll/pinch to zoom the cross-section — the engine is longer than the frame at high zoom.