Tokamak Energy ST80-HTS hailed as next step to grid fusion

According to the Oxford-based company, the ST80-HTS will be the world’s first high field spherical tokamak using high temperature superconducting (HTS) magnets. Planned for completion in 2026, the new reactor is the company’s latest step towards commercial fusion power and will inform the design of its ST-E1 fusion pilot plant, which will target up to 200MW of net fusion power in the early 2030s.   

Tokamak Energy says the ST80-HTS will aim to deliver a higher triple product than any previous fusion device. Widely accepted as a yardstick by which to gauge progress towards commercial fusion, triple product (nT𝝉𝝉E) combines measurements of plasma density, temperature and confinement. Dense plasma ensures better chances of particles collisions, high temperature plasma allows fusion reactions to take place, while longer confinement time provides a bigger window for sustained reactions.

Tokamak Energy has already achieved plasma temperatures in excess of 100m°C with its ST40 spherical tokamak. It will attempt to replicate these temperatures on the ST80-HTS, but extend the pulse duration significantly, targeting pulses up to 15 minutes. Combined with sufficient plasma density, this should deliver a triple product approaching what is required for a commercial fusion power plant.