{
  "meta": {
    "key": "fusion_energy_gain",
    "title": "Fusion Energy Gain",
    "unit": "Q",
    "category": "Energy",
    "source": "Wurzel & Hsu, Lawson-criterion compilation",
    "sourceUrl": "https://arxiv.org/abs/2505.03834",
    "verified": "2026-10-20",
    "url": "https://exponentialtracker.com/curve/fusion_energy_gain",
    "csv": "https://exponentialtracker.com/data/fusion_energy_gain.csv",
    "json": "https://exponentialtracker.com/data/fusion_energy_gain.json",
    "retrievedFrom": "Compiled by Exponential Tracker and re-derived from the source named above. Rebuilt on every deploy, so re-fetch rather than trusting a saved copy to be current.",
    "rights": "The underlying data belongs to Wurzel & Hsu, Lawson-criterion compilation. This compilation may be reused with attribution to Exponential Tracker. No licence is claimed or implied over the source data.",
    "citation": "Exponential Tracker, \"Fusion Energy Gain\", exponentialtracker.com/curve/fusion_energy_gain, data verified 2026-10-20. Underlying source: Wurzel & Hsu, Lawson-criterion compilation."
  },
  "data": [
    {
      "year": 1991.86,
      "value": 0.12,
      "label": "JET: the first compiled D-T gain"
    },
    {
      "year": 1994.4,
      "value": 0.28
    },
    {
      "year": 1997.83,
      "value": 0.63,
      "label": "JET: the last tokamak record (power basis)"
    },
    {
      "year": 2021.6,
      "value": 0.69,
      "label": "NIF: burning plasma — the metric changes hands (energy basis)"
    },
    {
      "year": 2022.93,
      "value": 1.51,
      "label": "NIF: scientific breakeven — more energy out than laser in"
    },
    {
      "year": 2023.58,
      "value": 1.89
    },
    {
      "year": 2024.12,
      "value": 2.36
    },
    {
      "year": 2025.15,
      "value": 2.44
    },
    {
      "year": 2025.27,
      "value": 4.13,
      "label": "NIF: 8.6 MJ from 2.08 MJ, the standing record"
    }
  ]
}