# Hefei Fusion (DD-738)

> On June 27, 2026, the Institute of Plasma Physics in Hefei (ASIPP) completed and accepted a toroidal field superconducting magnet for CRAFT, China's Comprehensive Research Facility for Fusion Technology. The magnet weighs 582.4 t, measures 21 × 12 × 3.3 m, operates at 98 kA and stores 120 GJ. Sixteen such coils would produce 6.5 T at the plasma center and a 14.5 T peak. ASIPP says it has 1.3 times the volume and three times the stored energy of an ITER TF magnet, making it the world's largest fusion-reactor superconducting magnet.

- Department: Tech (also Science)
- First published: 2026-09-11
- Last updated: 2026-09-11
- Permalink: https://detailenjoyer.com/case/hefei-fusion/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## On the timeline

- **June 27, 2026**: CRAFT toroidal field magnet passes acceptance in Hefei

Full timeline: https://detailenjoyer.com/timeline/?case=hefei-fusion

## Quick facts

- **DD-738-F01**: The Hefei TF magnet operates at 98 kA and stores 120 GJ. _(Write-up · Exhibit B (The numbers))_
- **DD-738-F02**: ASIPP says it has three times the stored energy of an ITER TF magnet. _(Write-up · Exhibit C (Compared with ITER))_

## Write-up

A 582-ton superconducting magnet built for fusion research. Built in Hefei for China's CRAFT fusion test facility.

1. **Completed in June 2026**: On June 27, 2026, the toroidal field (TF) magnet, the largest component of CRAFT, completed its final manufacturing steps and passed acceptance testing. CRAFT is a national research facility in Hefei for testing key fusion-reactor systems.
2. **The numbers**: A single TF magnet measures 21 m long, 12 m wide and 3.3 m high and weighs 582.4 t. It operates at 98 kA and stores 120 GJ. Sixteen such magnets would produce 6.5 T at the plasma center and 14.5 T at the coils.
3. **Compared with ITER**: According to ASIPP, the magnet has 1.3 times the volume and three times the stored energy of an ITER TF magnet. The institute describes it as the world's largest fusion-reactor superconducting magnet.
4. **What it does**: Toroidal field magnets create the field that confines plasma at hundreds of millions of degrees and reduces particle damage to the vessel walls. They must run reliably for 60 years at very low temperatures, high currents and high radiation.
5. **How it was tested**: The project took six years. Conductor samples were tested thousands of times at 4.2 K, with cycles at 100 kA and 12 T. A high-temperature-superconducting central solenoid coil also completed full-parameter testing the same day.

## Related case files

- [(Z) Pinch Me (DD-741)](https://detailenjoyer.com/case/z-pinch-me/): Another approach to confining fusion plasma: a Z-pinch squeezes it with its own current's magnetic field.
- [Quantum Infrastructure (DD-012)](https://detailenjoyer.com/case/quantum-cryogenics/): More superconducting hardware: quantum computers chilled to 10–20 thousandths of a degree above absolute zero.

## Reel vs. record

- **Missing context**: the magnet was built for CRAFT, China's fusion-technology test facility in Hefei, not an operating reactor. It passed acceptance on June 27, 2026.
- **Precision**: 98 kA is the magnet's operating current rather than an 'up to' maximum. Conductor samples were tested at 100 kA and 12 T.
- **Attribution**: 'world's largest' and the comparison with ITER (1.3 times the volume, three times the stored energy) are claims made by the developer, ASIPP.
- **Missing context**: sixteen such TF coils would produce 6.5 T at the plasma center and a 14.5 T peak field.
- **Missing context**: the coil is designed for a 60-year life under extreme cold, high current and radiation. A high-temperature-superconducting central solenoid coil passed full-parameter testing the same day.

## Video: Hefei Fusion: A 582-Ton Superconducting Magnet Built for Fusion Research

- Duration: 24.2 s · Published: 2026-09-11
- File: https://detailenjoyer.com/assets/videos/DdJzplpRxjT.mp4

### Transcript

DID YOU KNOW? China has completed a 582.4-ton superconducting toroidal field magnet, designed for next generation fusion research. Built by the Institute of Plasma Physics in Hefei, this enormous D-shaped structure measures about 21 m long, 12 m wide, and 3.3 m high. It carries up to 98,000 amps and stores roughly 120 GJ of magnetic energy. NOW YOU KNOW!

## Questions & answers

**Q: How much does the Hefei TF magnet weigh?**  
A: 582.4 t. _(Source: Write-up · Exhibit B (The numbers) · ASIPP (Chinese): 国际最大的聚变堆超导磁体研制成功 (June 27, 2026); China News Service via CAS: 全球尺寸最大聚变堆超导磁体在合肥下线)_

**Q: What is its operating current?**  
A: It operates at 98 kA. _(Source: Write-up · Exhibit B (The numbers) · ASIPP (Chinese): 国际最大的聚变堆超导磁体研制成功 (June 27, 2026); China News Service via CAS: 全球尺寸最大聚变堆超导磁体在合肥下线)_

**Q: Which facility is it for?**  
A: CRAFT, China's fusion-technology research facility in Hefei. _(Source: Write-up · Exhibit A (Completed in June 2026) · ASIPP (Chinese): 国际最大的聚变堆超导磁体研制成功 (June 27, 2026); China News Service via CAS: 全球尺寸最大聚变堆超导磁体在合肥下线)_

**Q: How does its stored energy compare with an ITER TF magnet, per ASIPP?**  
A: ASIPP says three times the energy storage. _(Source: Write-up · Exhibit C (Compared with ITER) · ASIPP (Chinese): 国际最大的聚变堆超导磁体研制成功 (June 27, 2026); ASIPP (English): Two core superconducting magnet systems for fusion reactors (July 2026); Chinese Academy of Sciences: World's Largest Superconducting Magnet for Fusion Reactor Unveiled in Hefei)_

**Q: What design life is the magnet built for?**  
A: It must run reliably for 60 years. _(Source: Write-up · Exhibit D (What it does) · Chinese Academy of Sciences: World's Largest Superconducting Magnet for Fusion Reactor Unveiled in Hefei)_

## Sources

- [ASIPP (Chinese): 国际最大的聚变堆超导磁体研制成功 (June 27, 2026)](https://ipp.cas.cn/xwdt/ttxw/202606/t20260627_847049.html)
- [ASIPP (English): Two core superconducting magnet systems for fusion reactors (July 2026)](http://english.ipp.cas.cn/news/202607/t20260702_848383.html)
- [Chinese Academy of Sciences: World's Largest Superconducting Magnet for Fusion Reactor Unveiled in Hefei](https://english.cas.cn/newsroom/cas-in-media/202606/t20260629_1175003.shtml)
- [China News Service via CAS: 全球尺寸最大聚变堆超导磁体在合肥下线](https://www.cas.cn/cm/202606/t20260629_5113864.shtml)

## Cite this case file

Easterling, Marcus. "Hefei Fusion." The Detail Department (DetailEnjoyer), case file DD-738, last updated Sep 11, 2026. https://detailenjoyer.com/case/hefei-fusion/