Momentum Imaging of Dissociative Electron Attachment to Molecules

Dissociative electron attachment (DEA) to diatomic and polyatomic molecules, including O$_2$, C$_2$H$_2$, and CO$_2$, is studied using a COLTRIMS apparatus which is capable of imaging 3D dissociation dynamics upon impact from a low energy ($\sim$10eV) electron. A pulsed electric field is used to extract and distinguish ion fragments in a time-of-flight mass spectrometer, from which a complete picture of the reaction dynamics may be constructed. Through the axial recoil approximation, dependence of the attachment probability on a molecule's orientation with respect to the incoming electron's momentum is revealed.