We report the experimental observation of cavitons a in an Argon plasma, produced and heated by an rf field and confined by a magnetic mirror system. The cavitons are simultaneously observed in the electron density Ne (dip), the electron temperature Te (peak), the floating potential Vf (dip) and in the rf fields (peak). They are stable in time, sharply localized and stationary in space and there is equilibrium between the ponderomotive and the thermokinetic forces. Their widths is of the order 2.0 to 4.0 cm, ?Ne/Ne* ? 100% and ?Te/Te*?200%.
