I have been blogging about nuclear fusion lately. There are a lot of different projects being carried out by governments and private companies dedicated to the development of a safe, inexpensive, and non-polluting commercial fusion reactor that could provide for the world’s energy needs. While there are some popular approaches such as tokamaks that confine superhot plasmas with magnetic fields and other approaches called inertial confinement that use laser bursts to cause fusion pulses, some researchers have been working on more esoteric ways of triggering fusion for energy production.
     NASA is currently researching something called “lattice confinement” to produce nuclear fusion. In this approach, deuterium is loaded into narrow channels between the atoms of a solid metal. The metal lattice is held at ambient temperature as the deuterium is loaded. While the system is at room temperatures, the individual deuterium atoms experience an environment where they are subject to high energies.
      When deuterium atoms which are also called deuterons are loaded into a metal like erbium, they are packed a billion times denser that even the most power magnetic confinement systems can achieve. In this new approach, a neutron source is used to accelerate the deuterons in the metal lattice so that they collide with neighboring deuterons with sufficient energy for deuterium – deuterium fusion to take place.
     Because the deuterons are packed so densely inside the metal lattice, the energy necessary to trigger fusion is much, much lower than the energy needed for magnetic confinement or inertial confinement. The lattice aids the process by acting as a filter to determine which particles pass through the lattice. It even pushes the deuterons together. Obviously, there is a huge gap between individual atoms at energy rates that resemble fusion and an actual commercial scale application of nuclear fusion.
     NASA says that this research is only a first step that offers an alternative to the enormous cost and complexity of magnetic and inertial confinement being studied. Even the smallest magnetic confinement reactors require temperatures equivalent to those found in the center of the Sun. Generating and maintaining the high temperatures and huge pressures for these prototype fusion reactors is very difficult. While these conditions may be attained in the laboratory, whether or not they would ever be practical for a commercial nuclear fusion reactor is a question that remains to be answered.
      There are many types of fusion reactor designs being researched, but if a way could be found to create fusion reactions without the need for extreme temperatures and pressures, it would be much simpler and cheaper. Such reactors would be much smaller than the big magnetic confinement systems and might be suitable for applications that big fusion reactors would not be. However, before such lattice confinement systems can be the basis of commercial nuclear fusion reactors, the researcher have to find a way to increase the rate of fusion reactions in the lattice far beyond the rate currently displayed in the initial experiments. The NASA team says that they do have some solid ideas about how to do that.