The dream of limitless fusion energy is one step closer to being realised. Chinese scientists claim to have developed the first heat-resistant panels engineered for the International Thermonuclear Experimental Reactor (ITER).
Officially the world’s largest fusion reactor, ITER is a global collaborative project involving several countries, including the UK, EU member states, India, Russia, Japan and Switzerland.
Sandwiched between Nice and Marseille in the south of France, ITER’s construction began in 2013, with the first reactor assembled seven years later in 2020.
Estimates of the project’s cost are between $22 and $65 billion, making the complex one of the most expensive scientific endeavours ever.
China is tasked with manufacturing 54 of the 440 panels that will line the inside wall of the reactor, known as the “first wall”. Measuring 1 x 1.5 metres, each tile is made from an amalgam of beryllium, stainless steel and copper alloy.
They must endure temperatures close to 4.7 megawatts per square metre. To put this into context, the sun radiates roughly 1 370 watts per square meter or 0.00137 megawatts, according to the Australian Government Bureau of Meteorology.
Panels that make up the first wall will be subjected to plasma pulses, with temperatures in excess of 100 million degrees Celsius, and will remain functional for two decades – the entire planned operating window for ITER.
Despite the intense heat of the plasma, the wall’s surface remains relatively cool by comparison, explained Director General of ITER, Pietro Barabaschi.
Barabaschi said that the superheated plasma was confined by a powerful electromagnetic field, preventing the plasma from unwanted contact with the first wall that dissipates heat.
The Italian-born ITER chief said the Chinese panels were critical to the success of the entire project as they defined the plasma boundary.
Chief scientist at China’s National Nuclear Corporation, Chen Jiming, said incorporating the beryllium and copper alloy into the panels proved to be a significant stumbling block for the research team.
If the panels fail, molten copper and beryllium could fall into the plasma and cause the reactor to fail. Chen told Sichuan Online that, after multiple unsuccessful efforts, laser welding the materials together provided the best results.
Several EU nations and Russia are charged with developing first wall panels too and are making good progress, according to the South China Morning Post.
A prototype of the reactor was completed and has undergone tests as recently as last year. Once operation approval is granted, the reactor could start producing plasma by 2025.