Commonwealth Fusion Systems: HTS Magnet Performance Milestones
| Milestone | Date | Field Strength Achieved | Significance | |
|---|---|---|---|---|
| SPARC TFMC demonstration (industry-first commercial HTS tokamak magnet) | 2021-09 | 20 Tesla at 20 K | Nature paper Sep 2021; validated REBCO architecture at commercial scale; opened HTS-tokamak path | |
| MIT PSFC + CFS HTS tape supply chain build-out | 2022-Q2 to 2023-Q4 | N/A (manufacturing capacity scaling) | Established stable REBCO tape supply via Faraday Factory + Fujikura + AMSC + others | |
| SPARC TF Coil #1 manufactured + factory-tested | 2023-Q3 | Confirmed 20+ T performance at full coil scale | First production TF coil at full SPARC scale (~10 m tall) | |
| SPARC TF Coil #2-6 manufactured + tested | 2023-Q4 to 2024-Q4 | Confirmed performance per design | Scaling magnet production cadence through factory | |
| SPARC TF Coil #7-12 production | 2025-Q2 to 2025-Q4 | Performance per design | Continued production cadence | |
| SPARC TF Coil set complete (all 18 coils) | Target 2026-Q1 | Performance per design | Required for SPARC mechanical complete + first plasma | |
| Central solenoid + poloidal field coils complete | Target 2026-Q3 | Performance per design | Final magnet subsystems before SPARC first plasma | |
| ARC commercial magnet design freeze | Target 2028 | Higher field strength + duty cycle vs SPARC | ARC commercial scale-up; design improvements over SPARC magnets | |
| ARC magnet production begins | Target 2029 | Performance per ARC design | Following SPARC operational validation | |
| Editorial. Why this matters | Strategic context | HTS magnets are the structural enabler of compact + commercial-scale fusion tokamaks. CFS's 2021 TFMC demonstration established the company-unique competitive lead. Marquee question: does CFS maintain its HTS magnet lead vs Tokamak Energy (the only comparable HTS tokamak developer) + emerging Chinese + European programs, or does the HTS supply chain mature enough that the lead narrows? |
Updated at 2025-Q3
Commonwealth Fusion Systems: SPARC Construction Progress at Devens MA
| Subsystem | Status | Milestone Date | Significance | |
|---|---|---|---|---|
| Devens MA campus + tokamak hall | Operational | 2023-Q3 | Tokamak hall fully constructed; supporting facilities operational | |
| HTS magnet manufacturing (Tokamak Field Magnet Coils) | TFMC SPARC demonstration successful 2021 | 2021-09 (TFMC 20 T at 20 K) | Industry-first commercial-scale HTS tokamak magnet; validated REBCO architecture | |
| Central solenoid assembly | Manufacturing in progress at supplier | On track for 2025 delivery | REBCO-based; combined with TF coils provides plasma confinement | |
| Vacuum vessel fabrication | Manufacturing in progress at supplier | On track for 2025-2026 delivery | First-wall + neutron shielding integrated | |
| Toroidal Field (TF) coil set production | First 6 of 18 TF coils complete + tested | Production target complete 2026-Q1 | Each TF coil ~10 m tall + ~1.5 m wide; HTS REBCO tape | |
| Plasma diagnostics + control systems | Design phase complete; supplier procurement in progress | Target operational 2026-Q3 | Real-time plasma control + diagnostics for Q > 1 demonstration | |
| SPARC first plasma (mechanical complete) | Target 2026-Q4 to 2027-Q1 | On schedule (revised from original 2025 target) | Original Series B 2021 target was 2025; current target 2026 to 2027 H1 | |
| SPARC Q > 1 net energy gain demonstration | Target 2027 (revised from 2026) | On schedule per current commercial roadmap | The scientific milestone; required for ARC commercial commitments | |
| ARC commercial design freeze (Virginia) | Target 2028 | Design work in progress alongside SPARC operations | Google ARC Virginia PPA (Jun 2025; 200 MW) anchored on this milestone | |
| ARC FOAK commercial operation (Virginia) | Target 2030 | On schedule per Series B + Series B2 roadmaps | Marquee commercial-fusion target; on schedule vs original announcement | |
| Editorial. Why this matters | Strategic context | CFS + SPARC is the most aggressive credible commercial-fusion timeline + the only fusion developer with a binding commercial PPA tied to demonstration timelines (Google + ARC, Jun 2025). HTS magnet technology is the company-unique enabler. Marquee question: does SPARC achieve Q > 1 on schedule (2027) + does that validate the broader HTS-tokamak path that ARC depends on? |
Updated at 2025-Q3
