Multiphoton ionization of molecules: A comparison between femtosecond and nanosecond laser pulse ionization efficiency

34Citations
Citations of this article
11Readers
Mendeley users who have this article in their library.

Abstract

Multiphoton ionization mass spectra of nonvolatile molecules laser desorbed into a supersonic beam are recorded. It is shown by indirect measurements that the laser desorption of neutrals is not mass limited, but lead to the formation of neutrals with intesities large enough for intense signals. To investigate the efficiency of the multiphoton ionization process with varying laser pulse durations, simultaneous laser pulses of 500 fs and 5 ns or 100 fs and 5 ns have been applied to the neutral beam. The energies of both femtosecond and nanosecond laser pulses are held in a comparable magnitude, and thus produce, in the resulting ion intensity, very large differences up to 4 orders of magnitude. For larger evaporated molecules (〉 500 u) the ionization efficiency from nanosecond laser pulses drops significantly in comparison to femtosecond laser pulse excitation. A variety of possible reasons for the different ionization and dissociation behavior in femtosecond and nanosecond laser pulse excitations are discussed in this paper. It is rationalized that even with very short laser pulses and large molecules the “ladder switching model” for ionization and fragmentation is valid. © 1995, American Society for Mass Spectrometry. All rights reserved.

Cite

CITATION STYLE

APA

Aicher, K. P., Wilhelm, U., & Grotemeyer, J. (1995). Multiphoton ionization of molecules: A comparison between femtosecond and nanosecond laser pulse ionization efficiency. Journal of the American Society for Mass Spectrometry, 6(11), 1059–1068. https://doi.org/10.1016/1044-0305(95)00551-X

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free