French scientists breakthrough: Fusion reactor hits sun's core heat

The potential of nuclear fusion technology to transform our energy landscape is immense. Experts are honing the process of fusing atomic nuclei. In the case of the French WEST fusion reactor, as National Geographic reports, scientists managed to keep plasma at a staggering 122 million degrees Fahrenheit for six minutes, far outstripping the core temperature of the Sun, which sits at around 27 million degrees Fahrenheit.

The team at the Princeton Plasma Physics Laboratory reached this milestone. While setting a new record marks significant progress in nuclear fusion technology, it's essential to recognize that developing power plants based on this tech will likely take many years. Achieving stable plasma maintenance for extended periods, not just a few minutes, is crucial.

Nuclear fusion emulates the natural processes at the core of the Sun, where hydrogen atoms merge to form helium, releasing enormous energy in the process, vastly exceeding that from nuclear fission.

National Geographic highlights that a kilogram of fusion fuel — primarily a mixture of hydrogen isotopes deuterium and tritium — can produce energy fourteen million times greater than a kilogram of fossil fuel, all while avoiding greenhouse gas emissions. These impressive figures underline nuclear fusion's potential as an inexhaustible, clean energy source.

Luis Delgado-Aparicio, leading advanced projects at PPPL, describes nuclear fusion as akin to creating an "artificial Sun on Earth." This is a formidable challenge, as it requires reaching temperatures higher than the Sun's core amidst lower pressure levels to facilitate fusion.

Another significant hurdle is sustaining the nuclear fusion reaction, which is prone to quick extinguishment, particularly with fuel contamination. Additionally, for fusion to be viable, it must produce more energy than the amount used to heat the plasma to such extreme temperatures. The latest experiments have generated 15% more power despite not achieving net energy production.

Tokamaks, characterized by their donut shape with a central hole, are a specific type of fusion reactor where plasma is contained by a strong magnetic field. The choice of material for the reactor walls is a critical design consideration.

Initially, the WEST reactor used carbon for its walls due to its ease of handling, but it absorbed tritium from the fuel mixture. In 2012, this was switched to tungsten, which, despite its challenges such as melting and plasma contamination at high temperatures, will also feature in the ITER reactor, the most significant experimental fusion reactor project in southern France.

PPPL scientists have also developed an enhanced diagnostic tool for precise plasma temperature monitoring and tracking tungsten movement within the reactor. These insights will inform the ongoing work on the ITER reactor.