Dissociative electron attachment to CF₂Cl₂

Using a recently constructed high resolution crossed electron/molecular beam apparatus consisting of a hemispherical electron monochromator and a quadrupole mass spectrometer we have measured the relative production cross sections for Cl^- and F^- via electron attachment to CF₂Cl₂. The relative Cl^- cross section is placed on an absolute scale by reference to an absolute rate coefficient using a calibration method involving in-tegration of the measured anion signal. The most efficient Cl^- production process is at about zero energy and its magnitude is resolution limited. The present high resolution value of 6 × 10^-16cm² compares well with an earlier value reported by Chen and Chantry. A second peak is detected at around 0.8 eV in accordance with some of the earlier beam and swarm measurements. The observed production of F^- has an appearance energy of 1.9 eV and the energy of maximum cross section is 3.36 eV, the latter value comparing well with several previous studies.