Molecular fragmentation by electron impact investigated using a time delayed spectroscopic technique

A new technique based on time-of-flight mass spectrometry with delayed extraction, in which it is possible to determine the amount of ions with a given energy distribution, is presented. Unlike most techniques designed to measure the energy distribution of molecular fragments, its sensitivity is higher in the low range of the energy distribution, for ions with kinetic energy from thermal energy up to 3 eV. In this progress report we show that this technique is able to open new perspectives for mass spectrometry based on the well established TOF technique, presenting some selected results for collisions of electrons with energy between 15 eV and 400 eV with N₂, O₂ and CHClF₂, which have interesting features involving their low energy fragments