In a bid to solve the planet’s clean energy needs, Chinese scientists have built a fusion reactor device meant to imitate a star. During a four month long experiment, the Experimental Advanced Superconducting Tokamak (EAST), nicknamed the “Chinese artificial sun”, achieved an electron temperature of over 100 million degrees in its core plasma, which is seven times hotter than the sun.
The EAST team at the Hefei Institutes of Physical Science of the Chinese Academy of Sciences collaborated with a team of Chinese and international scientists to reach this milestone. Their method involved optimizing the reactor’s current density profile through the effective integration and synergy of four kinds of heating power: lower hybrid wave heating, electron cyclotron wave heating, ion cyclotron resonance heating and neutral beam ion heating. This led to the EAST’s power injection exceeding 10 MW, and boosting stored plasma energy to 300 kJ.
The scientists carried out experiments on plasma equilibrium and instability, confinement and transport, plasma-wall interaction and energetic particle physics to demonstrate long-time scale, steady-state High confinement mode (H-mode) operation with sufficient control of impurity, core/edge magnetohydrodynamics (MHD) stability, and heat exhaust using a tungsten divertor similar to the one used in the International Thermonuclear Experimental Reactor (ITER), a notable energy project in France. This led to EAST achieving a fully non-inductive steady-state scenario with extension of fusion performance at high density, high temperature and high confinement.
To resolve the particle and power exhaust, which is imperative for high-performance steady-state operations, the EAST team employed numerous techniques to control the edge-localized modes and tungsten impurity with metal walls, along with active feedback control of the divertor heat load.
Operating scenarios created by the EAST team including the steady-state high-performance H-mode and electron temperatures over 100 million degrees on EAST have made unique contributions towards ITER, the Chinese Fusion Engineering Test Reactor (CFETR) and DEMO.
This experiment is a follow up to the milestone the EAST team achieved last year when it set a new world record in “long-pulse H mode operation”. The team explained that highlight as “achieving a stable 101.2-second steady-state high confinement plasma.” The next step was raising the temperature of the plasma to star-like levels, which the EAST team has now done. This could go a long way towards helping humankind create an almost unlimited supply of clean energy through nuclear fusion.
The EAST experiments are carried out at the Hefei Institutes of Physical Science of the Chinese Academy of Science.