Physical and chemical effects on crystalline H_2O_2inducedby 20 keV protons

摘要

We present laboratory studies on radiation chemistry, sputtering, and amorphization of crystallineH202 induced by 20 keV protons at 80 K. We used infrared spectroscopy to identify H_2O, O_3, andpossibly HO_3, measure the fluence dependence of the fraction of crystalline and amorphous H_2O_2and of the production of H_2Oand destruction of H_2O_2. Furthermore, using complementarytechniques, we observe that the sputtering yield depends on fluence due to the buildup of O_2radiation products in the sample. In addition, we find that the effective cross sections for thedestruction of hydrogen peroxide and the production of water are very high compared to radiationchemical processes in water even though the fluence dependence of amorphization is nearly thesame for the two materials. This result is consistent with a model of fast cooling of a liquid trackproduced by each projectile ion rather than with the disorder produced by the formation of radiolyticproducts.