Temperature dependence of electron attachment to CHCl2Br - A crossed beams study

摘要

Dissociative electron attachment (DEA) to CHCl2Br has been studied in a crossed electron/ molecular beams experiment in the electron energy range between 0 and 8 eV and in the gas temperature range from 321 to 478 K. The two negative fragment ions Cl- and Br- are formed from a prominent low energy resonant feature close to zero eV and at comparatively weaker resonances at about 0.38 eV, 2.2 eV and 5.5 eV. In contrast to swarm experiments [7], the bihalogen ion Cl-2(-) was not detected in our experiment. The absolute partial cross-sections for Br- and Cl- reaction channels have been estimated. We find that in the low electron energy range (approximate to 0 eV) the overall DEA cross-section as well as the partial DEA cross-section for Br- formation slightly decrease with increasing gas temperature whilst the partial cross-section for the Cl- channel is temperature independent.