Low-energy electron dissociative attachment processes in HgBr2

Br- formation in HgBr2 has been studied by means of two cross-beam electron impact spectrometers, one equipped with a trochoidal electron monochromator and a magnetic mass analyser and the other one equipped with two 127 degrees electrostatic energy filters and a quadrupole mass analyser. It is found that the Br- cross section in the energy range 0-7 eV exhibits two peaks, at zero energy and 4.15 eV respectively. The energy distributions of Br- ions are obtained in the energy range of the second process, different interpretations are discussed.