Low energy electron interaction with HCOOH and CH3NO2

Experimental results of low energy, ∼0 - 10 eV, electron attachment to formic acid (HCOOH) and nitromethane (CH3NO2) are presented. In case of formic acid HCOO-, OH-, O- anions with intensity ratios (maximum peak values) of 240 : 10 : 1 were detected, whereas with nitromethane NO2-, O-. OH-. CN- and CNO- with intensity ratios of 100 : 10 : 2 : 1.5 : 1 were observed. For the above mentioned ions, absolute cross sections for electron dissociative attachment were obtained. In order to measure a accurate attachment cross sections a highly monochromatic electron beam is needed, therefore a trochoidal electron monochromator was used. In the experiments the electron energy spread used was 140 meV in case HCOOH and 150 meV with CH3NO2; for the calibration of the energy scale Cl- / CCl4 system was used. The experiments were performed at a pressure of about 10-6 mbar (HCOOH) and 2 x 10-6 mbar (CH3NO2) respectively. (nevyjel)