Fusion world

EAST achieves 403-second H-mode plasma

Experiments performed this month on the EAST superconducting tokamak in Hefei, China, have demonstrated record sustainment of high temperature plasmas in the so-called H-mode confinement regime, surpassing 400 seconds. 
ASIPP_EAST_403.jpg
At 9 p.m. on 12 April 2023, EAST set a new record by operating for 403 seconds in steady-state, high-performance mode (H-mode). Image courtesy of the EAST team.
H‐mode describes the sudden improvement of plasma confinement in the magnetic field of tokamaks by approximately a factor of two, and is the high confinement regime that all modern tokamaks, including ITER, rely on.

Scientists at EAST had broken the 100-second barrier for steady-state H-mode plasmas in 2017. Nearly 50,000 plasma shots later, on 12 April 2023, the team achieved a 403-second stationary H-mode plasma, and repeated the performance in a second shot the next day. 

Research at EAST on physics and technology issues under steady-state operational conditions is directly relevant to ITER. Song Yuntao, director of ASIPP, celebrated the milestone. "The EAST team has worked together closely with their collaborators at home and abroad over the past decades," in order to solve frontier physics and technical issues with long-pulse operation, he said. This includes "plasma configuration control, high efficiency radio frequency heating and current drive, plasma-wall interactions, and real-time diagnostics for key plasma parameters."

The latest achievement at EAST is an important milestone in the exploration of plasmas that will be required for ITER and for future fusion reactors. 

See more about the technical characteristics of the record shot in English or Chinese.