physics

Helion Energy

Helion Energy is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Helion Energy rather than just read about it. In short: Helion Energy, Inc. is an American fusion research company located in Everett, Washington. It is developing a magneto-inertial fusion technology to produce fusion power by combining deuterium with helium-3 via aneutronic fusion.

Key takeaways

Helion Energy belongs to physics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Helion Energy to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Helion Energy from memory before moving on to harder problems.

Reference excerpt

Helion Energy, Inc. is an American fusion research company located in Everett, Washington. It is developing a magneto-inertial fusion technology to produce fusion power by combining deuterium with helium-3 via aneutronic fusion.

History The company was founded in 2013 by David Kirtley, John Slough, Chris Pihl, and George Votroubek. In 2013, Helion was selected as a finalist in the Clean Tech Open, a nonprofit accelerator program supporting early-stage clean technology companies. The recognition highlighted the company's early work in magneto-inertial fusion and its potential applications for commercial electricity generation. In 2015, Helion participated in the Y Combinator startup accelerator as part of its Summer 2013 (S14) batch. The management team were awarded a 2015 ARPA-E ALPHA contract, "Staged Magnetic Compression of FRC Targets to Fusion Conditions". Helion Energy has been named a finalist for multiple GeekWire Awards, including Innovation of the Year (2022), Workplace of the Year (2023), and Sustainable Innovation of the Year (2025 and 2026). On May 10, 2023, Helion Energy announced that it had agreed to provide 50-MWe to Microsoft starting in 2028. This is the first commercial agreement for fusion energy. Commentators are skeptical. In October 2023, Helion and Nucor Corporation, the largest steel producer and recycler in North America, agreed to develop a 500-MWe fusion power plant at one of Nucor's manufacturing facilities. Their target for beginning operations is 2030. In 2026, Time named Helion to its TIME100 Most Influential Companies list, citing the company's progress toward commercial fusion power through its planned Orion power plant and Polaris fusion milestones. In February its Polaris prototype achieved two firsts for private fusion:

Demonstrated measurable deuterium-tritium (D-T) fusion. Reached record plasma temperatures of 150 million degrees Celsius In June, Helion became the first to clear key Washington state regulatory licenses for handling radioactive materials in preparation for its Orion power plant in Malaga and raised $465M in Series G funding, led by Thrive Capital, valuing the company at $15.5 billion.

Technology Helion's approach uses a linear fusion system with pulsed magnetic compression and differs from the traditional design for fusion reactions, which relies on tokamaks. The system is intended to operate at 1 Hz, injecting plasma, compressing it to fusion conditions, expanding it, and recovering the energy to produce electricity. The pulsed-fusion system used is said to be theoretically capable of running 24/7 for electricity production. Due to its compact size, the systems would be able to replace current fossil fuel infrastructure without major needs for investment.

Fuel Helion uses a combination of deuterium and Helium-3 (3He) as fuel. Deuterium and 3He allows mostly aneutronic fusion, releasing only 5% of its energy in the form of fast neutrons. Commercial 3He is rare and expensive. Instead Helion plans to produce 3He by deuteron–deuteron (D–D) side reactions to the D–3He reactions. D–D fusion has an equal chance of producing a 3He atom and of producing a tritium (3H) atom plus a proton. Tritium beta decays into more 3He with a half-life of 12.32 years. Helion plans to capture the 3He produced this way and reuse it as fuel. Helion has a patent on this process.

Development history The company's fusion generator is based on the inductive plasmoid accelerator (IPA) experiments performed from 2005 through 2012. These experiments used deuterium–deuterium fusion, which produced a 2.45-MeV neutron in half of the reactions. The IPA experiments claimed 300 km/s velocities, deuterium neutron production, and 2-keV deuterium ion temperatures. Helion and MSNW LLC published articles describing a deuterium–tritium (D–T) implementation that is the easiest to achieve but generates 14 MeV neutrons. The Helion team published peer-reviewed research demonstrating D–D neutron production in 2011.

5th prototype, 'Venti' In 2018, the 5th prototype, Venti, had magnetic fields of 7 T and at high density, an ion temperature of 2 keV. Helion detailed D–D fusion experiments producing neutrons in an October 2018 report at the United States Department of Energy's ARPA-E's annual ALPHA program meeting. Experiments that year achieved plasmas with multi-keV temperatures and a triple product of 6.4 × 1018 keV·s/m3.

6th prototype, 'Trenta' In 2021, the firm announced that after a 16-month test cycle with more than 10,000 pulses, its sixth prototype, Trenta, had reached 100 million degrees C, the minimum temperature where a commercial generator could run. This made Helion the first private fusion company to reach these temperatures. Magnetic compression fields exceeded 8 T, ion temperatures surpassed 8 keV, and electron temperatures exceeded 1 keV. The company further reported ion densities up to 3 × 1022 ions/m3 and confinement times of up to 0.5 ms.

7th prototype, 'Polaris'

Helion's seventh-generation prototype, Polaris, started in 2011 and completed in 2024. The device is expected to increase the pulse rate from one pulse every 10 minutes to one pulse per second for short periods. This prototype is expected to be able to heat fusion plasma up to temperatures greater than 100 million degrees C. Polaris is planned to be 25% larger than Trenta to ensure that ions do not damage the vessel walls. In August 2024, Helion received a Large Broad Scope license from Washington State Department of Health. This allowed Helion to possess and use necessary quantities of byproduct material to support the operation of Polaris. Helion completed construction of its seventh-generation prototype, Polaris, in late 2024 and began initial operations. While the company's original 2021 target was to demonstrate net electricity production in 2024, this milestone was not met. As of mid-2025, Helion reported that Polaris was operational and successfully forming the largest field reversed configuration (FRC) plasmas the company had created to date, with the goal of demonstrating net electricity production by the end of the year. As of December 2025, Helion had not announced that Polaris has achieved net production. Helion achieved 150 million degrees C D–T fusion as of February 13, 2026.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Helion Energy

Start with the simplest possible case. Write down what Helion Energy claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Helion Energy before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Helion Energy ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Helion Energy

In research: Helion Energy appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Helion Energy in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Helion Energy is common in secondary-school and first-year university syllabi. It links to neighbouring topics Accelerator physics, American companies established in 2013, Engineering companies of the United States, so understanding it makes those chapters shorter.
In everyday life: Look for Helion Energy outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Helion Energy in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Helion Energy means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Helion Energy out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Helion Energy in simple terms?

Why does Helion Energy matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Helion Energy?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Helion Energy.