A major problem with fusion is solved leading us closer to a perpetual energy source

The dynamics inside a fusion reactor are so complex sometimes the walls melt.

Oct 12, 2022

Without a doubt someday it is possible to have fusion power plants providing sustainable energy resolving our long-standing energy problems. This is the main reason so many scientists throughout the world are carrying out research on this power source. The generation of power from this method actually mimics the sun.

For the method to work, plasmas must be heated to 100 million degrees Celsius in reactors. Magnetic fields enclose the plasma keeping the walls of the reactor from melting. The shell that forms around the plasma can only work because the outermost centimeters of the edge of that shell, called the magnetically formed plasma edge, are extremely well insulated.

There is however a problem with this way of enclosing the sun-level heat of the plasma. In that edge region, there are plasma instabilities, called edge localized modes (ELMs). ELMs occur frequently, during the fusion reaction. During an ELM, energetic particles from the plasma may hit the wall of the reactor, potentially damaging it.

In a move that would remind anyone of offering an original of something after many trials of different methods, only to find out the original is the right one, the researchers went back to a mode of operation that had been discarded previously.

Instead of large destructive instabilities potentially damaging the walls of the reactor. There can be many small instabilities that do not pose a risk of damaging the reactor’s walls.

"Our work represents a breakthrough in understanding the occurrence and prevention of large Type I ELMs," says Elisabeth Wolfrum, research group leader at IPP in Garching, Germany, and professor at TU Wien. "The operation regime we propose is probably the most promising scenario for future fusion power plant plasmas." The results have now been published in the journal Physical Review Letters.

The reactor is called a toroidal tokamak fusion reactor. In this reactor, ultra-hot plasma particles move at high speeds. Powerful magnetic coils ensure that the particles remain confined instead of hitting the reactor walls damaging it.

How a fusion reactor works is complicated, and the dynamics inside are also complex. The motion of the particles depends on the plasma density, temperature and magnetic field. How these parameters are chosen dictates how the reactor will function. When the smaller particles of plasma hit the walls or the reactor, instead of a round shape, the reactor takes on a triangular shape with rounded corners, but the shape is far less damaged then with a large ELM.

"It's a bit like a cooking pot with a lid, where the water starts to boil," Georg Harrer lead author of the paper explains. "If the pressure keeps building up, the lid will lift and rattle heavily due to the escaping steam. But if you tilt the lid slightly, then steam can continuously escape, and the lid remains stable and doesn't rattle."

This is a big step to having a continuous fusion reaction with huge energy potential. A perpetual energy source

https://interestingengineering.com/science/a-major-problem-with-fusion-is-solved...

https://www.counterpunch.org/2022/12/16/fusion-really/

December 16, 2022



by Karl Grossman






“Nuclear fusion technology has been around since the creation of the hydrogen bomb,” noted a CBS News article covering the announcement. “Nuclear fusion has been considered the holy grail of energy creation.” And “now fusion’s moment appears to be finally here,” said the CBS piece.

But, as Dr. Daniel Jassby, for 25 years principal research physicist at the Princeton Plasma Physics Lab working on fusion energy research and development, concluded in a 2017 article in the Bulletin of the Atomic Scientists, fusion power “is something to be shunned.”

His article was headed “Fusion reactor: Not what they’re cracked up to be.”

“Fusion reactors have long been touted as the ‘perfect’ energy source,” he wrote. And “humanity is moving much closer” to “achieving that breakthrough moment when the amount of energy coming out of a fusion reactor will sustainably exceed the amount going in, producing net energy.”

“As we move closer to our goal, however,” continued Jassby, “it is time to ask: Is fusion really a ‘perfect’ energy source?” After having worked on nuclear fusion experiments for 25 years at the Princeton Plasma Physics Lab, I began to look at the fusion enterprise more dispassionately in my retirement. I concluded that a fusion reactor would be far from perfect, and in some ways close to the opposite.”

“Unlike what happens” when fusion occurs on the sun, “which uses ordinary hydrogen at enormous density and temperature,” on Earth “fusion reactors that burn neutron-rich isotopes have byproducts that are anything but harmless,” he said.


A key radioactive substance in the fusion process on Earth would be tritium, a radioactive variant of hydrogen.

Thus there would be “four regrettable problems”—“radiation damage to structures; radioactive waste; the need for biological shielding; and the potential for the production of weapons-grade plutonium 239—thus adding to the threat of nuclear weapons proliferation, not lessening it, as fusion proponents would have it,” wrote Jassby.

“In addition, if fusion reactors are indeed feasible…they would share some of the other serious problems that plague fission reactors, including tritium release, daunting coolant demands, and high operating costs. There will also be additional drawbacks that are unique to fusion devices: the use of a fuel (tritium) that is not found in nature and must be replenished by the reactor itself; and unavoidable on-site power drains that drastically reduce the electric power available for sale.”

“The main source of tritium is fission nuclear reactors,” he went on. Tritium is produced as a waste product in conventional nuclear power plants. They are based on the splitting of atoms, fission, while fusion involves fusing of atoms.

The article goes on...............