General Atomics (GA) reached another key milestone in the fabrication of the ITER Central Solenoid as engineers and technicians at GA’s facility officially completed heat treatment of the first module. The Central Solenoid – an integral component of ITER’s unprecedented fusion facility – will stand over five stories tall and will be the world’s most powerful pulsed superconducting magnet.
“The heat treatment is what ultimately creates the solenoid’s superconducting material, and completion of this process demonstrates that we are continuing to make good, consistent progress on this project,” said John Smith, GA’s program manager.
The process required to create the superconducting material inside the module windings is exacting. The temperature within the furnace can only change at a rate of five or six degrees Fahrenheit per hour, making both the heating and cooling processes very time consuming – it required more than one week for each.
In order to complete the critical heat treatment process, GA engineers and technicians positioned the first module in a massive one-and-a-half-megawatt furnace, which functions in a manner similar to that of convection ovens found in many kitchens. The benefit of the convection oven is the ability to shorten the overall process while maintaining uniform “cooking” of the module.
Inside the furnace, the module spent approximately ten-and-a-half days at 1,060 degrees Fahrenheit and an additional four days at 1,200 degrees Fahrenheit.
“After spending weeks carefully monitoring and controlling the temperature in the furnace, we will now begin the first of the module’s multiple insulation processes, called turn insulation. Simultaneously, samples that were heat treated along with the first module will be sent to the National High Magnetic Field Laboratory in Florida to be tested, proving the heat treatment successfully created the superconducting material needed for ITER’s solenoid,” Smith said. “GA is pleased with our progress on the Central Solenoid fabrication to date, and we are proud of each successive milestone that we reach.”