Two-photon ionization of trimethylamine using KrF laser radiation

Abstract

The multiphoton ionization of a low-pressure (3×10−5 Torr) fill of trimethylamine using an electron-beam pumped KrF laser has been studied. A microwave resonator probe was used to measure the resultant free-electron density. The scaling of electron density with the square of the incident laser intensity was verified in the low flux limit. The electron production decreased significantly from the I2 scaling at laser fluxes exceeding 4 MW/cm2. These results are consistent with a simple two-photon model describing the interaction in the low flux limit and a saturation of the electron production in the high-flux limit.