A novel ultra-cold plasma produced in the expansion region of a supersonic jet shows very intriguing properties that can be explained by electron degeneracy and possible formation of an electron Wigner crystal. The consequences of electron degeneracy on the crystallisation of the ions in the plasma is discussed. The experimental observation of plasma compression show that the plasma does not behave as a gas but it has condensed phase properties, in line with theoretical predictions. This novel plasma could open the perspective of obtaining a Bose-Einstein condensate of molecular cations.
