The evaporation of thin nonmetallic specimens under the effect of fission fragments

The authors have established that “thin” sources made from salts, and containing Cm242 and Cm244, are evaporated by fragments formed spontaneously in curium, the main role being played by fragments ments which pass along the surface of the source. The number of atoms evaporated from the Iatter per fragment varies with increasing source thickness h, reaching a maximum at h0=1.5·10−5 cm. This thickness corresponds to the effective radius of the thermal peak. With h≥h0, each fragment travelling along the surface evaporates ∼5·10−7 atoms, the other fragments ∼103 atoms. It is shown that the curve plotting the number of evaporated atoms versus source thickness reaches saturation at h≈7·10−6 cm.