Hollywood has made us wary of the last day before retirement, but for the MIT’s fusion reactor its final 24 hours of operation were some of its best. The reactor was able to produce plasma with 2.05 atmospheres of pressure for the first time, a major breakthrough in nuclear fusion research.
The Alcator C-Mod reactor has been in operation for 23 years and it had set the previous record of plasma pressure (1.77 atmospheres) in 2005. The plasma in the record-breaking event reached a temperature of 35 million °C (63 million °F) and was contained by a magnetic field 144,000 times stronger than the magnetic field of our planet.
Nuclear fusion reactors aim to govern the power that makes stars shine. To get the energy, it is necessary to trap, in a modest volume, a large enough number of atoms for a long enough period of time at an incredibly high temperature.
Out of these three parameters, density, temperature, and time, the plasma pressure is directly linked to the first two. The power you can extract from a fusion reactor increases as the square of the pressure. If you double the pressure, you get four times the power.
Alacator C-Mod is a tokamak, one of the two approaches in nuclear reactor designs (the other is the stellarator). Tokamaks have donut-shaped chambers where the plasma is trapped by strong magnetic fields. They are considered the most promising fusion reactor designs for their safety and reliability.
"Compact, high-field tokamaks provide another exciting opportunity for accelerating fusion energy development, so that it's available soon enough to make a difference to problems like climate change and the future of clean energy – goals I think we all share," Professor Dennis Whyte, director of the Plasma Science and Fusion Center and head of the Department of Nuclear Science and Engineering at MIT, said in a statement.
While the breakthrough, presented at the International Atomic Energy Agency (IAEA) Fusion Energy Conference, is significant, we are still far away from commercial nuclear fusion power stations, although progress is being made.
Right now, 35 nations are collaborating to build ITER in France, a prototype nuclear fusion power station. ITER will push our current technological limits, and hopefully open the road to safe, clean, and abundant energy. It is expected to start operations in December 2025, so Alacator’s record is safe for the next decade.