Electronic Sputtering from H2O:C2H6 ice bombarded by energetic heavy ions.

H 2 O:C 2 H 6 ice mixture, in a proportion of approximately 1:10 and at 60 K in average, is irradiated by energetic multicharged ions (≈ 65 MeV 252Cf fission fragments). The sputtered positive and negative secondary ions are analyzed by time-of-flight plasma desorption mass spectrometry (PDMS-TOF). Several ionic species are identified, indicating strong surface fragmentation and clusterization. The bombardment induces the formation of the ion cluster series: (CH 2) n X, where X = CH 3 + , C 2 H 6 + or CH + , and the carbon cluster series (C) n X, where X = CH 3 + or CH −. It is found that, in general, the yield distributions exhibit exponential decays, Y = Y 0 F e x p (− k F n) + Y 0 S e x p (− k S n) , where k F =1.11 u−1 and k S =0.11 u−1. Such finding may be useful to understand the processes by which, in cosmic space, ionized molecular species of hydrocarbons are delivery to the gas phase. [ABSTRACT FROM AUTHOR]