{
  "title": "Generic Hall-effect thruster teaching cutaway",
  "source_reference": {
    "document": "NASA SmallSat State of the Art 2026, In-Space Propulsion",
    "figure": "Figure 4.30, physical PDF page 36 / printed page 91",
    "sha256": "a5b2aa5843f4b8c09e2eb855f30f4038ad7ff2b588171dee2755932c8253e81c",
    "use": "Figure informed component roles and one central-cathode arrangement; dimensions and CAD geometry are original teaching proportions."
  },
  "coordinate_convention": {
    "axis": "+Z downstream through channel",
    "radial": "XY plane",
    "open_cutaway": "90-degree sector removed where X >= 0 and Y >= 0; explanatory only"
  },
  "units": "mm used solely for CAD exchange; all lengths are arbitrary visualization proportions, not scale, tolerances, or engineering dimensions.",
  "parameters": {
    "axis": "+Z downstream along the annular discharge channel",
    "removed_sector_degrees": 90,
    "channel_inner_radius": 12.0,
    "channel_outer_radius": 20.0,
    "channel_axial_start": 0.0,
    "channel_axial_exit": 25.0,
    "inner_wall_inner_radius": 10.5,
    "inner_wall_outer_radius": 12.0,
    "outer_wall_inner_radius": 20.0,
    "outer_wall_outer_radius": 21.5,
    "wall_back_z": -2.0,
    "wall_exit_z": 27.0,
    "outer_case_inner_radius": 21.5,
    "outer_case_outer_radius": 25.0,
    "case_back_z": -7.0,
    "case_exit_z": 27.0,
    "manifold_inner_radius": 11.0,
    "manifold_outer_radius": 21.5,
    "manifold_back_z": -7.0,
    "manifold_front_z": -2.0,
    "anode_inner_radius": 12.0,
    "anode_outer_radius": 20.0,
    "anode_back_z": -2.0,
    "anode_front_z": 0.0,
    "cathode_stem_radius": 1.15,
    "cathode_stem_back_z": -5.0,
    "cathode_stem_front_z": 14.0,
    "cathode_body_radius": 3.1,
    "cathode_body_back_z": 14.0,
    "cathode_body_front_z": 33.0,
    "cathode_emitter_radius": 2.0,
    "cathode_emitter_back_z": 33.0,
    "cathode_emitter_front_z": 37.0
  },
  "component_count": 8,
  "included_components": [
    "Outer casing",
    "Inner channel wall",
    "Outer channel wall",
    "Rear annular propellant manifold",
    "Annular anode",
    "Central cathode support stem",
    "Central cathode body",
    "Cathode emitter tip"
  ],
  "schematic_glyphs": {
    "stored_in_cad": false,
    "items": [
      "E axial +Z",
      "B radial +X at the +X exit location",
      "local E×B electron drift +Y there",
      "ion outflow +Z"
    ],
    "limits": "PNG arrows are explanatory direction glyphs only; no field map, field magnitude, electron/ion trajectory, speed, or operating point is computed. The +Y E×B direction follows +Z cross +X at the indicated location."
  },
  "not_modeled": [
    "magnet hardware or its placement",
    "magnetic/electric field magnitude",
    "voltage or electrical circuit",
    "propellant feed internals beyond conceptual annular manifold",
    "plasma or ionization",
    "particle trajectories",
    "thrust",
    "power",
    "efficiency",
    "thermal behavior",
    "erosion",
    "lifetime",
    "structural strength",
    "manufacturing tolerances",
    "flight or performance validation"
  ],
  "configuration_boundary": "Central cathode is one arrangement shown in the source example; other Hall-thruster designs may locate the cathode externally. The quarter cut is a visualization opening, not a physical aperture. No acceleration grids are included.",
  "validation": {
    "model_solids": 8,
    "all_original_solids_valid_positive_volume": true,
    "step_roundtrip_solids": 8,
    "all_step_roundtrip_solids_valid_positive_volume": true,
    "step_bytes": 112989,
    "stl_bytes": 331284
  }
}