WHAM is a high-field (17 T HTS) axisymmetric magnetic mirror experiment built by UW-Madison with Realta Fusion and CFS-made magnets, which achieved first plasma in July 2024. It underpins Realta's tandem-mirror plant concept; in 2026 Realta partnered with utility MGE to explore a ≥200 MWe Wisconsin fusion plant by the mid-2030s.
New to fusion? Nuclear fusion, explained: three ways to bottle a star
Current state
| Status | Operating |
| Country | United States |
| Location | Wisconsin Plasma Physics Laboratory, Stoughton, Wisconsin |
| Developer | University of Wisconsin-Madison / Realta Fusion |
| Developer type | Public-private |
| Concept | Magnetic mirror |
| Fuel | D-D |
| Purpose | Research |
| First plasma | 2024-07-16 |
| Public funding | ARPA-E funding for WHAM; Realta is a DOE Milestone program awardee; Wisconsin/Madison up to $55m for Realta Forge HQ |
Notes
Realta's cumulative funding not confirmed (launched with $12M in 2022; $36M Series A 2025), so private funding raised not recorded. The MGE plant (≥200 MWe, mid-2030s) is exploratory and has no separate record.
Timeline
- 2024-07-16 — WHAM achieved first plasma with 17 T HTS mirror magnets. (source)
- 2025-05-13 — Realta Fusion raised an oversubscribed $36 million Series A. (source)
- 2026-09-03 — Realta and Madison Gas and Electric announced a partnership, including MGE equity, to explore a fusion plant of at least 200 MWe in Wisconsin. (source)
The timeline is append-only: corrections are added as new entries. Stated targets appear in the current-state table, never as milestones.
Related projects
- ARC (Commonwealth Fusion Systems) Design · United States
- Athena (Xcimer Energy) Concept · United States
- Century (Zap Energy) Operating · United States
- Copernicus (TAE Technologies) Under construction · United States
- Da Vinci / first utility-scale plant (TAE Technologies) Concept · United States
- Demonstration System (Pacific Fusion) Under construction · United States
- Eos (Thea Energy) Design · United States
- FLARE fusion neutron source (SHINE Technologies) Operating · United States
See all 51 projects in the Fusion Energy Companies & Projects Tracker →
Sources
- First plasma marks major milestone in UW-Madison fusion energy research — Universities of Wisconsin (primary), checked 2026-10-11
- WHAM: Realta gets first plasma with 17 Tesla magnets in mirror fusion test — ANS Nuclear Newswire, checked 2026-10-11
- Realta Fusion Raises $36 Million Series A — PR Newswire / Realta Fusion (primary), checked 2026-10-11
- Realta Fusion's utility partnership boosts fusion energy in Wisconsin — ANS Nuclear Newswire, checked 2026-10-11