Secondary ion emission from CO2-H2O ice irradiated by energetic heavy ions

Projectile-ice direct coulomb interaction leads to the production in the track of the H+, C+, O+, O2+, CO+ and CO2+ primarily ions, which react in the highly energized nuclear track plasma mainly with CO2 and H2O or H2CO3. The positive molecular hybrid ions formed are identified as organic species like COH+, COOH+, CHn = 1-3+, Hn = 1,2COOH+ and cluster ions. Similarly, the negative primarily ions O− and OH− formed by electron capture produce negative hybrid ions such as (CO2)nOH−, the four ions (CO4Hm = 0-3)− and the corresponding cluster ions. By far, most of the molecular ions have been formed by one-step reactions; exceptions are eventually the CO4Hm− ions created by a reaction between CO3− and water molecules. An intense mass line corresponding to HCO3+ has been observed, but not the one due to formaldehyde ion. Weak signals of ionic ketene, hydrogen peroxide and carbonic acid were seen.