Comment by opticfluorine

Minor nit, Joule-Thomson is not just the ideal gas law - it is a separate thermodynamic effect entirely. Case in point, for certain gases the change in temperature due to Joule-Thomson has the opposite sign that you would predict from the ideal gas law alone.

This has interesting applications. For example, you can exploit this with dilute metal vapor in an expanding helium gas to cool the metal vapor to very low temperature - the Joule-Thomson expansion of helium increases the helium's temperature by converting the energy of the intermolecular forces into heat. This draws out energy from the metal vapor. If done in a vacuum chamber, then in the region before the shockwave formed by the helium, the supercooled metal atoms will form small van der Waals clusters that can be spectroscopically probed in the jet. This was an interesting area of study back in the 80s that advanced our understanding of van der Waals forces.