Absolute cross-sections for the nonresonant multi-photon ionization of toluene and xylene in the gas phase Original Research Article

The absolute multi-photon ionization cross-section of the phenyl ring was determined by laser-ionization of toluene and xylene molecules in the gas phase. Excitation was achieved using nonresonant four-photon absorption of the frequency doubled light of a 10 ns pulsed Nd:YAG laser (532 nm). The resulting ions were stored in a Penning trap and detected by time-of-flight mass spectrometry. The values of the cross-sections are 1.4(3)×10−42 cm8 W−4 s−1 and 1.3(3)×10−42 cm8 W−4 s−1 for toluene and xylene, respectively.