Finally the tequila sunrise plasma

This plasma may be reminiscent of summer or tequila sunrise, but is beautiful bright plasma always a good thing?  The unique spectral emission of a gas or vapor plasma results from the relaxation of electrons from their excited states.  Electrons form discreet orbits around the nucleus of an element or compound.  Energy is released in the form of light when an electron falls from a higher energy state to a lower energy state.  The distance the electron fell governs the wavelength of the light that is emitted.   But how important is the intensity of the glow? The more energy you put into a system the greater the intensity of the glow and the concentration of reactive species.  But this does not necessarily mean a greater degree of surface modification.  Ions generate friction and if the mean free path is not sufficiently small then heat may disrupt or reorient the polymeric surface that is being modified.  Too much energy is also responsible for ablation and fragmentation of compounds and/or larger molecules.  Too much fragmentation of a surface may leave you with a weak boundary layer.  Pulsed power and low duty cycles make for less interesting plasma.  But in a lot of situations this helps preserve the chemical structure of the matter being constructed.  Controlling the energy and energy delivery is often important when it comes to custom polymerization of ultra thin coatings.