A custom built tandem quadrupole mass spectrometer is being used to study the fundamentals of low energy (10-100 eV) polyatomic ion surface collisions. Low energy ion surface collisions have shown great promise for structural characterization of incident ions or for use in modifying the surface.

Our interesting the fundamentals of low energy ion surface collisions is primarily geared towards developing the emerging technique of Surface Induced Dissociation (SID) tandem mass spectroscopy. This technique is similar to the currently widely used method of collision induced dissociation (CID). Both SID and CID can be used for the structural characterization of organic compounds, however SID has shown promise for use as a complementary analysis technique. SID has been shown to have greater fragmentation efficiencies than CID which in cases may be desirable. However, the potential of Sid has not been realized because relatively little is known about the fundamentals of low energy ion-surface collisions.

Our work has primarily focused on the mechanism by which ios-surface associative products are formed. Experimental evidence and thermodynamic calculations suggest that a sputtered ion mechanism is a likely reaction pathway for polyatomic ions colliding with hydrocarbon surfaces. In this s mechanism the incident ion undergoes charge exchange with a surface species with the subsequent release of a sputtered hydrocarbon fragment. In a gas phase like reaction with the neutralized incident ion and the sputtered ion react to form the observed associative product.