Chapter 4

Phase 1: Data Format

Standardized data formats for plasma state, diagnostics, and energy output enable interoperability across fusion devices worldwide.

The Need for Standardization

Today, every fusion facility uses its own data formats, naming conventions, and units. A "shot" at KSTAR might be called a "pulse" at JET and a "discharge" at DIII-D. Temperature might be in keV, eV, Kelvin, or degrees Celsius. This fragmentation makes it difficult to compare results, share analysis tools, or train AI models on data from multiple devices.

WIA-FUSION Phase 1 defines a universal data format based on JSON Schema, with clear definitions for all plasma parameters. This enables plug-and-play interoperability while remaining flexible enough to accommodate device-specific extensions.

Plasma State Schema

The core of the WIA-FUSION data format is the plasma state schema, which captures the complete instantaneous state of a fusion plasma:

{
  "$schema": "https://wialive.smilestory.ai/schemas/fusion/v1.0.0",
  "plasma_state": {
    "shot_id": "KSTAR-20240415-001",
    "timestamp": "2024-04-15T10:30:00.150Z",
    "reactor": "KSTAR",

    "core_parameters": {
      "temperature_keV": { "ion": 10.2, "electron": 9.8 },
      "density_m3": { "value": 1.05, "unit": "1e20/m3" },
      "confinement_time_s": 3.2,
      "triple_product": { "value": 34.3, "unit": "keV·s·1e20/m3" }
    },

    "performance": {
      "q_factor": 1.18,
      "fusion_power_mw": 0,
      "plasma_current_ma": 1.8,
      "beta_percent": 2.5
    },

    "stability": {
      "disruption_risk": { "value": 0.15, "confidence": 0.92 },
      "elm_frequency_hz": 50,
      "mhd_activity": ["m=2,n=1"]
    },

    "control": {
      "heating_power_mw": {
        "ohmic": 0.5, "nbi": 12, "icrh": 3, "ecrh": 2
      },
      "magnetic_field_t": 3.5,
      "divertor_heat_mw_m2": 8
    }
  }
}

Core Parameters

Field	Type	Units	Description
temperature_keV	object	keV	Ion and electron temperatures (1 keV ≈ 11.6 M°C)
density_m3	object	10²⁰/m³	Plasma particle density
confinement_time_s	number	seconds	Energy confinement time
triple_product	object	keV·s·10²⁰/m³	n × T × τ fusion metric

Performance Metrics

Field	Type	Description
q_factor	number	Fusion gain (P_fusion / P_input)
fusion_power_mw	number	Total fusion power output
plasma_current_ma	number	Plasma current in mega-amperes
beta_percent	number	Ratio of plasma to magnetic pressure

Diagnostic Data Format

Fusion devices use dozens of diagnostic systems to measure plasma properties. WIA-FUSION standardizes how this data is represented:

{
  "diagnostic_data": {
    "diagnostic_id": "thomson_scattering_core",
    "timestamp": "2024-04-15T10:30:00.150Z",
    "sampling_rate_hz": 100,
    "data": [10.2, 10.1, 9.8, 9.5, 9.0, 8.2, 7.0, 5.5, 3.2, 1.5],
    "radial_positions": [0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9],
    "units": "keV",
    "calibration_version": "2024-01-15",
    "quality_flag": "good"
  }
}

Energy Output Schema

For power plant applications, the energy output schema tracks electricity generation:

{
  "energy_output": {
    "gross_fusion_power_mw": 500,
    "thermal_power_mw": 550,
    "net_electric_power_mw": 165,
    "plant_efficiency_percent": 33,
    "availability_factor": 0.85,
    "tritium_breeding_ratio": 1.1,
    "neutron_wall_loading": { "value": 1.5, "unit": "MW/m2" }
  }
}

Validation

All data must pass JSON Schema validation before being accepted. The schema enforces:

• Required fields are present
• Values are within physical limits
• Units are correct
• Timestamps are valid ISO8601 format