Nuclear Fusion·Vanderbilt University·Est. 2022
Built by undergraduates.
First plasma in 2025.
Fusion next.
HELIOS Mk. 1 — our student-built inertial electrostatic confinement reactor — achieved plasma under fusion operating conditions in Spring 2025. With Vanderbilt EH&S approval secured, we're preparing first deuterium fusion runs in Fall 2026.
- I.
Achieved
First plasma · Spring 2025
- II.
Approved
Vanderbilt EH&S · Spring 2025
- III.
Planned
D-D fusion · Fall 2026
To spark innovation by doing what looks impossible — and to train the engineers who'll do it next.
The Mission · 2022—2026
Timeline · 2022 — 2026
Four milestones. One arc.
Each step represents real hardware, an approval granted, or a commitment on the record.
- [01]2022
Founded & Funded
A dorm-room conversation becomes a project — and an institutional one. Vanderbilt University and a founding circle of major donors commit early backing through the V150 Dare to Grow campaign.
- [02]2024
Assembled
HELIOS Mk. 1 fully built. Every pump, wire, and line of control code — student-fabricated.
- [03]Spring 2025
Plasma
First plasma under fusion operating conditions. Vanderbilt EH&S approval granted.
- [04]Fall 2026
Fusion
First deuterium fusion runs with an off-campus partner facility.
Specifications · Mk. 1
Measurements.
Every number is a parameter the team designed for, validated, or aimed at. Achieved values are measured results; design targets are labeled as such.
Equivalent plasma temperature at peak operation — roughly 25 × the core of the sun.
Fig. 02 · Temperature scale · log K
Maximum operating voltage — key-armed, telemetry-monitored HV supply.
Ultimate vacuum pressure — roughly ten billion times below atmospheric.
Stable particle beam current into the cathode cage.
Fusion events at peak operation.
Deuterium gas purity during operation.
0
Undergraduates on the team.
0+
Majors represented — engineering to history.
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System teams, from mechanical to ML controls.
1st
Student-built IEC reactor to achieve plasma under fusion operating conditions in the U.S.
The Reactor · HELIOS Mk. 1
High Energy, Low Input
Operating Source.
A compact inertial electrostatic confinement reactor, designed and built by undergraduates at Vanderbilt. First plasma: Spring 2025. Hover a part on the schematic — or pick from the list — to see what it does.
Build · 2024
Installing the high-voltage feedthrough on HELIOS Mk. 1.
[01] · Star-in-a-jar · D⁺ recirculation
Plasma core
Deuterium ions accelerate inward through the cathode grid, focus near the geometric center, then recirculate outward through the open cage geometry — forming the iconic magenta lobes you see in any operating fusor.
- What it is
- A compact, modular IEC reactor — plasma achieved under fusion operating conditions.
- What's next
- First deuterium fusion runs, Fall 2026, with an off-campus partner facility.
- Why it matters
- Low-cost access to an extreme plasma environment previously gated by national labs.
Origin · 2022
It started
in a dorm room.
Late one night in 2022, a group of first-year students at Vanderbilt was brainstorming projects in a residence-hall lounge. Most of the ideas evaporated by morning. One didn't.
“What if we built a nuclear fusion reactor?”
Three years later, the lights are red and the reactor is live. HELIOS Mk. 1 sits in a darkened operations room at Vanderbilt — a Spellman high-voltage rack, a control console with a key-armed E-stop, a yellow safety chain, and a small team watching the chamber glow.
HELIOS Mk. 1 has now achieved plasma under fusion operating conditions, and the team has grown from eight founders to sixty students across twenty majors — the country's first fully student-driven nuclear reactor initiative, on track for deuterium fusion in 2026.
Research pillars · Eight system teams
Four fronts. One reactor.
Engineering, physics, computer science, biomed, chemistry — plus political science and history. The interdisciplinary mix is the message.
- [01]
Mechanical Systems
Vacuum & flowing gas
Ultra-high vacuum chamber, two-stage pumping, and a mass-flow-controlled deuterium path engineered for clean, reproducible operation.
- Ø ~10 cm
- UHV · 8e−8 Torr
- D₂ mass-flow
- [02]
Electrical & Control
High-voltage power and mechatronics
Key-armed 50 kV supply with real-time telemetry. Every interlock is physically keyed — only trained safety officers arm the stack.
- ≤ 50,000 V
- 10 mA beam
- Telemetry → DAQ
- [03]
Computational Physics
Plasma modeling and applied ML
Live telemetry feeds plasma models and a machine-learning control layer. Closed-loop optimization — the reactor learns to tune itself.
- Closed-loop ML
- Plasma models
- Anomaly flags
- [04]
Advanced Concepts
Accelerators, materials, futures
From particle-beam deposition to neutron-exposure studies — the research adjacencies a compact, controllable plasma platform opens up.
- Nanomaterials
- Neutron studies
- Mk. 2 design
Two ways in
Build with us, or back us.
Join the team.
Applications open each semester. We recruit across every major at Vanderbilt — curiosity and commitment matter more than prior experience.
Apply nowSupport the project.
We're backed by the Office of the Chancellor and individual donors through Vanderbilt's V150 Dare to Grow campaign.
See sponsorsThe Logbook · Notes from the lab
How the work actually goes.
Long-form writing from the team — reactor progress, controls, safety, and what we're learning at the bench. Published when there's something worth saying.