Athena by Xcimer Energy: status and timeline

Milestones

Next · Vulcan laser engineering demonstration

DOE approves pre-conceptual designJun 2026Complete.
Vulcan laser engineering demonstrationTarget 2031Not yet reached.
Final power plant design completedTarget 2033Not yet reached.
Construction beginsTarget 2034Not yet reached.
First fusion electricity to gridTarget 2035Not yet reached.

Most important updates

Department of Energy approves Xcimer Athena fusion power plant pre-conceptual designJun 2026

Upcoming

2031Vulcan laser engineering demonstration (next)
2033Final power plant design completed
2034Construction begins
2035First fusion electricity to grid

Current obstacles

Scaling from prototype to 400 MW plant1000–10000x increase in complexity and reliability from Phoenix and Vulcan.
Molten salt erosion at commercial powerHigh-energy fusion produces intense flux; salt must survive years without degradation.
Economic competitiveness with gas plantsMust match natural gas peaking plants on cost per MWh for market adoption.

Physics limits

Molten salt thermal properties are fixedHeat capacity, conductivity, melting point are immutable; scaling requires more salt/temperature.
Laser efficiency near physics limitExcimer lasers already among most efficient; major gains require revolutionary physics.

How it works

3 parts

Multi-beam compression

Multiple Vulcan lasers on one target

Multiple Vulcan systems focus beams on single fuel pellet, compressing to fusion.

Energy capture

Molten salt captures fusion heat

Salt absorbs neutrons and heat; carries energy to heat exchanger for electricity.

Steam generation

Turbine drives electricity generation

Heat drives conventional steam cycle to generate 400 MW grid power continuously.

Spec sheet

Spec	Athena
Power plant output	400 MW^R (reported)
Vulcan laser energy	4–12 MJ^R (reported)
Laser cost target	Under $100/joule^R (reported)

^R reported by the company

Update log

1 update

Jun 2026

Major: Department of Energy approves Xcimer Athena fusion power plant pre-conceptual designRegulatorRegulatory

About Xcimer Energy

The team behind Athena

Xcimer Energy

Excimer laser fusion, KrF laser, molten salt

Laser inertial confinement fusion startup founded 2022, Denver. Uses KrF excimer lasers and molten salt chambers. DOE approved Athena 400 MW power plant design June 2026.

Phoenix laser operational June 2026: world's largest privately owned laser, 1 kJ.
DOE approved Athena pre-conceptual design June 2026: 400 MW power plant mid-2030s.
Molten salt chamber self-renews, no first-wall replacement; laser cost <$100/joule.

Company profile →

Founded: 20224 yrs
Headquarters: United States
Status: Private
Valuation: private
Works in: EnergyFusion
Coverage: 2 programs · 3 updateslatest 1 Jun 2026checked 11 Oct
Partners: U.S. Department of Energy
People: Conner GallowayFounder, CEO & Chief Scientific OfficerAlexander ValysFounder, President & Chief Technology Officer

Spec

Athena

Power plant output

400 MW^R (reported)

Vulcan laser energy

4–12 MJ^R (reported)

Laser cost target

Under $100/joule^R (reported)