Experimental Advanced Superconducting Tokamak (EAST) Exceeds Greenwald Limit and Breaks Nuclear Fusion Density Record

Key facts

• The breakthrough was performed at the Experimental Advanced Superconducting Tokamak (EAST), nicknamed the 'Artificial Sun', which is China’s cutting-edge fusion reactor.
• EAST has already broken a variety of records, including the longest sustained ultra-hot plasma for 1,066 seconds – that’s 17 minutes and 46 seconds of plasma well beyond 100 million degrees Celsius.
• Nuclear fusion reactors work by reproducing what goes on inside the Sun where hydrogen atoms merge, turning into helium atoms and releasing a lot of energy.
• By tweaking the initial parameters, such as the gas pressure and the heating resonance of the electrons in the plasma – how the particles respond to microwaves – the team was able to get densities with no instabilities at 1.3 to 1.65 times the Greenwald limit.
• The findings suggest a practical and scalable pathway for extending density limits in tokamaks and next-generation burning plasma fusion devices, said study co-lead author Ping Zhu, a professor in the School of Electrical and Electronic Engineering at the University of Science and Technology in China.
• The study is published in the journal Science Advances.