| In this thesis, particle emissions (neutrals, ions, electrons, and photons) from laser interactions with three materials, polytetrafluoroethylene (PTFE), magnesium oxide (MgO) and sodium nitrate (NaNO{dollar}sb3{dollar}), are studied. All three materials are normally transparent at all excimer laser wavelengths. Therefore surface and near surface defects play a key role on the laser interaction with these materials.; In PTFE, the neutral species (principally the monomer, {dollar}rm Csb2Fsb4{dollar}) formed during laser irradiation are produced by the thermal decomposition and the ionic species are produced by the ionization of neutral products by electron collisions in the weak plasma generated at the target surface. The absorption constant at 248 nm on the sample after 0.5-3 J/cm{dollar}sp2{dollar} laser irradiations is higher than that on the fresh, unirradiated sample.; At fluences well below the threshold of the plume formation, the major ion emission from 248 nm laser irradiation on MgO is Mg{dollar}sp+{dollar}. The Mg{dollar}sp+{dollar} kinetic energies are higher than the energy of the incident photon. Weak Mg{dollar}sp{lcub}2+{rcub}rm, MgOsp+, and Mgsb2Osp+{dollar} emissions are also observed at these fluences. The observed Mg{dollar}sp+{dollar} and Mg{dollar}sp{lcub}2+{rcub}{dollar} kinetic energies are consistent with electrostatic repulsion of adsorbed cations following photoionization of electron traps beneath the cation.; NaNO{dollar}sb3{dollar} is very susceptible to radiolysis by energetic electrons. The major neutral emissions from prolonged electron irradiation are NO and O{dollar}sb2{dollar} which are produced by dissociative electron attachment on nitrate ions. Defects are created by the decomposition of nitrate ions following electron bombardment. The particle emissions during laser irradiation of electron-irradiated NaNO{dollar}sb3{dollar} are greatly enhanced. The threshold of the plasma formation (the onset of the Na D-Line emission) is also dramatically reduced. |
