Understanding Helium 3 And Helium 4

When understanding or at least trying to understand the whole concept of super fluidity in physics it is important to first understand the two most basic core components of the experiments therein. In the case of Helium 3 it is interesting to note that it is not found largely on the planet earth, but it is a requirement in the research of nuclear fusion. This rare element helium 3 is found in abundance on the moon. It is found in the upper layer of the regolith, on the moon and since billions of years, the solar winds have been responsible for embedding helium 3 on the moon.

Gas giants of the solar system were responsible for leaving a gas such as helium 3, which is proposed by scientists to be used as a power source for nuclear fusion. The element Tritium in its 12 ½ years life is supposed to decay into Helium 3. In a nuclear reactor, when lithium goes through a process of irradiation many kilos of radioactive hydrogen called tritium can be produced, while helium 3 is produced after the decay of tritium. This important isotope called helium 3 plays an important part in the instrumentation of neutron detection

It is used as a converter gas in the neutron detectors as it has a high absorption for beams of thermal neutrons. During the nuclear reaction the neutron is converted in particles of tritium that are charged, as well as proton. In the case of Helium 4, it becomes a super fluid when it is cooled down to -271 degrees centigrade. When this process is observed, the properties of helium 4 are very different from other ordinary liquids. When helium 4 is kept in a metal vessel that is kept open, what you will see is that, a thin film climbs up the walls of the container and will slowly start overflowing.

This phenomenal behavior is difficult to be understood. Out of the eight known isotopes of the helium element, only helium 4 as well as helium 3 is known to be stable. Helium 4 is the most common isotope produced by alpha decay of radio active elements that are heavier. Alpha particles of helium 4 have nuclei that are fully ionized. Nucleus of helium 4 is unusually stable as the nucleons of this element are arranged in complete shells.

By using evaporative cooling liquid helium 4 can be cooled in a 1-K pot, to 1 Kelvin. Physicist L. D. Landau's experiments on these two naturally available core components of super fluidity revealed that the excitations generated during the experiment arose from the velocity of flow and the momentum observed during the experiment. It is on this basis that he came up with the definition of the density of any normal fluid. He gives us to understand that this density stands at zero and at temperature. It gradually and most certainly does increase with temperature. The important occurrence at this point remains that helium 4 does not exists as a super fluid!