The Contribution of The Joule-Thomson Effect To Solar Coronal Heatin

Two of the three gases that display isenthalpic Joule-Thomson (JT) warming under laboratory conditions are hydrogen and helium, the main constituents of the solar plasma, as the inversion point at which expansion results in heating is only ~51 K for helium and ~193 K for hydrogen, but the temperatures that are attained by this route are at most a few hundred K. Increases in ion temperature by several orders of magnitude are claimed for hydrogen plasmas subject to expansion into a vacuum; modest increases are reported for the short lived tests of this effect that have been carried out in space in the wakes of artificial satellites and of the Moon.