Multiply Charged Intact Ions of Polyatomic Cyclic Molecules Generated by a Strong Laser Field

Abstract

The interaction of strong laser fields (∼1016 W/cm2) with cyclic polyatomic molecules have been studied at λ = 790 and 395 nm. The induced ionization/fragmentation processes were analyzed by means of a time-of-flight mass spectrometer. The production of multiply charged intact ions is found to be related to molecular structure. Doubly charged intact ions were observed for aromatic molecules (aniline, furan, and pyridine) with significant abundance at both wavelengths used. No evidence for doubly charged species appeared in the mass spectra of the cycloketones. The single ionization mechanism is believed to be different at the wavelengths used. There is evidence that multiply charged ion production is taking place through sequential ionization processes, although the rescattering model cannot be excluded.