Nuclear Fusion Switch: Tungsten Ions to Replace Sodium

While advocates of healthy eating look for options of substituting sodium in salt, nuclear physicists working on making nuclear fusion a reality are also looking for substitutes of their own. They have thus far discovered that sodium-like tungsten ions could successfully replace the troublesome element, and that they could also provide a convenient method of monitoring the hot plasma required for attaining nuclear-fusion reactions.

Vast amounts of clean power are hypothetically available from nuclear fusion, a process very much different from nuclear fission, on which today's nuclear power plants function. In fusion, the nuclei of atoms are not broken apart, but rather fused together. This requires a lot of energy to perform, and the only documented instances of this happening can be found in stars, which sustain this type of reactions naturally. On the Earth, fusion can only be obtained through a hydrogen-bomb explosion, but the reaction is uncontrollable and, therefore, useless for energy production.

The International Thermonuclear Experimental Reactor (ITER) will most likely be the immediate beneficiary of the new find. The international magnetic confinement fusion (tokamak) project will undoubtedly have some of its high-strength structural components made up with the tungsten ions, rather than the sodium ones, as planned. The thinking goes that, as the super-hot plasma in the ITER reactor starts eroding electrons off its containment structure, it would strip some of tungsten as well. When 63 of the tungsten's 74 electrons are removed, it becomes virtually the same chemical as sodium – an atom surrounded by 11 electrons.

The major differences appear when it comes to the light the two elements emit. Sodium gas spews yellow-orange light, 99 percent of it in visible wavelengths – the “D” spectral lines. Sodium-like tungsten ions emit the same lines in the extreme ultraviolet wavelengths, because the electrons are more energetic. By analyzing the emitted light, experts could get a clue of what is happening inside the reactor, and monitor the plasma mix more closely.