Magnetic field triples energy yield in nuclear fusion
The energy yield from inertial fusion could be tripled through the use of magnets. Inertial fusion is a type of nuclear fusion that is also used to detonate hydrogen bombs.
Livermore (USA). Scientists at the National Ignition Facility (NIF), part of the Lawrence Livermore National Laboratory (LLNL), are researching what is known as inertial fusion. It is a form of nuclear fusion in which a tiny pellet of fuel is heated so much that the outer layer explodes. The pressure of this explosion compresses the fuel inside the sphere so much that a fusion reaction begins.
This method is already used when detonating hydrogen bombs. As the researchers led by John Moody published in the Physical Review Letters , it is also suitable for igniting the hydrogen isotope deuterium in millimeter-sized gold jars.
Nuclear fusion in a gold box
To ignite the fuel in the gold box, the researchers fired 192 lasers at the inside. This caused the inside to emit X-ray waves, which in turn heated a point on the fuel pellet so intensely that the fusion reaction ignited.
Generating such a hotspot used to be extremely complex. Even the smallest bumps on the surface of the fuel bead caused the reaction to fail.
Strong magnetic field helps with hotspot
The NIF researchers have now significantly simplified the creation of the hotspot using a strong magnetic field . In their experiment, the magnetic field served as an insulator, holding the excited particles in place. It was thus possible to increase the temperature of the hotspot by 40 percent without melting the gold case.
“The field is like a thick styrofoam sleeve that keeps my coffee hot without burning your hand.”
Tripled the energy yield of inertial fusion
The higher temperature of the hotspot has resulted in inertial fusion firing three times better, thus tripling the energy yield . In their next experiments, the physicists want to test whether what they call a “remarkable result” can also be achieved with a deuterium-tritium mix as fuel.
Physical Review Letters, doi: 10.1103/PhysRevLett.129.195002