Acceleron Fusion
🇺🇸 Cambridge, US · Active
Acceleron Fusion is a startup in Cambridge, Massachusetts, working on muon-catalysed fusion. A muon is an unstable particle about 207 times heavier than an electron; when it takes an electron's place in a hydrogen molecule it pulls the nuclei close enough to fuse without extreme heat, but making muons has so far cost more energy than the fusion returns. Acceleron says it is developing a cheaper muon source and a high-density fuel cell so that each muon catalyses more reactions, and that its fuel would run at 500 to 1,000 °C. In September 2024 it tested its machine with compressed deuterium–tritium fuel at the Paul Scherrer Institute's High Intensity Proton Accelerator. In December 2024 it closed a $24 million Series A round co-led by Lowercarbon Capital and Collaborative Fund.
- Sector
- Fusion
- Technology
- Muon-catalysed fusion
- Fuel
- Deuterium–tritium
- Role
- Fusion developer
Its recorded equity, $24m, is the 24th largest of the 25 organisations with a priced round here. Not every round is on record, so this is not its total raised.
Terms
- Muon-catalysed fusion
- A negative muon temporarily replaces an electron in a D-T (or D-D) molecule, pulling the nuclei roughly 200 times closer together than an electron would, so fusion happens at room temperature without confining a hot plasma at all. Added as its own branch of the fusion tree rather than filed under magnetic or inertial confinement, because it confines nothing: the muon does the work electromagnetically at the molecular scale. No net-energy device has been built: a muon typically catalyses only 100-150 fusions before it is captured by a helium nucleus and lost, and the main open problem is extending that cycle count, or cutting the cost of producing muons, enough to get more energy out than went into making them.
- Deuterium–tritium
- Lowest ignition threshold; 80% of energy in 14.1 MeV neutrons. The reference fuel for every near-term net-gain claim.
Funding
- 2024-12Equity round · Series ASeries A led by Lowercarbon Capital and Collaborative Fund.$24m