POSSIBILITY OF A CHARGE-EXCHANGE INDUCED COLLAPSE OF THE HELIOSHEATH

We investigate a possibility of the post-termination shock solar wind being cooled by interaction with neutral hydrogen atoms of interstella r origin. The efficiency of cooling depends critically on the ratio of the cooling time scale (proportional to neutral hydrogen density n(H) ) to the effective flow time of the plasma fluid element through the h eliosheath layers. We find out, basing on the hydrodynamical model wit hout magnetic field, that the cooling leads to formation of a thin, co ld and hence compressed plasma layer lining the inner side of the heli opause. For n(H) greater than or equal to 0.1 cm(-3) and the heliopaus e radius greater than or equal to 100 A.U. the thickness of the layer with the effective compression over the immediate post-shock value of the order of 5 may attain approximate to 0.5-2 A.U.. We discuss the im plication of this mechanism for entrapment of VLF radiation in the hel iospheric cavity and filtering of neutral interstellar atoms.