Strong field ionization of β-estradiol in the IR: Strategies to optimize molecular postionization in secondary neutral mass spectrometry

Andrew Kucher, Andreas Wucher, Nicholas Winograd

Research output: Contribution to journalArticlepeer-review

12 Scopus citations

Abstract

Strong field laser photoionization of β-estradiol in the 1013-1015 W/cm2 intensity range at wavelengths between 1200 and 2000 nm was examined for both evaporated gas phase molecules and neutral species sputtered from a solid surface under bombardment with 20 keV C60+ ions. It is shown that the ionization efficiency is saturated at laser intensities of the order of 1013 W/cm2, while laser-induced photofragmentation is found to strongly increase between 1013 and 1014 W/cm2 and stay constant at higher intensities. These findings suggest a strategy to improve the postionization efficiency by defocusing the laser beam in order to sample a larger fraction of the sputtered plume, while at the same time optimizing the conditions for intact photoionization of the sputtered molecules. The results reveal a substantial enhancement of the signal of intact postionized molecular ions to a level an order of magnitude above that of the corresponding secondary ions. They also provide an experimental estimate of ∼2.5 × 10-2 as an upper bound for the ion fraction (secondary ion formation probability) of the sputtered molecules. (Figure Presented).

Original languageEnglish (US)
Pages (from-to)25534-25544
Number of pages11
JournalJournal of Physical Chemistry C
Volume118
Issue number44
DOIs
StatePublished - Nov 6 2014

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Energy(all)
  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films

Fingerprint Dive into the research topics of 'Strong field ionization of β-estradiol in the IR: Strategies to optimize molecular postionization in secondary neutral mass spectrometry'. Together they form a unique fingerprint.

Cite this