CONTRIBUTION OF EXCITED STATES IN THE HEAVY ION RADIOLYSIS OF CYCLOOCTANE

摘要

The yields of the major end products produced in cyclooctane have been used to probe the effects of the track structure on radiation chemical processes induced by γ-rays, 1-15 MeV protons (LET 50-10 eVm), 5-20 MeV helium ions (LET 150-70 eVm), 7-29 MeV carbon ions (LET 800-660 eVm) and 10 MeV oxygen ions (LET 1150 eVm). There is a gradual decrease in the yields of cyclooctene, bicyclooctyl, and bicyclo octane (pentalane) with increasing LET and there appears to be a considerable change in the yields of individual primary decomposition channels with varying LET. Shifting from γ-radiolysis to proton radiolysis results in an increase in product formation through the triplet state with a concomitant decrease in the singlet excited state, probably due to the enhanced probability of cross combination reactions of electrons and cations in the high density region of heavy particle tracks. It appears that the yield of both the triplet and singlet excited states of cyclooctane slowly decrease with increasing LET.