Triply Differential Studies of Atomic and Molecular Photoionization Using Synchrotron Radiation.
Abstract
Basic studies of the dynamics and spectroscopy of atomic and molecular photoionization have been carried out using three experimental probes. The first and most extensively used experimental approach involves triply differential (differential in incident wavelength, electron energy, and ejection angle) photoelectron measurements using synchrotron radiation. Measurements were conducted in the vacuum ultraviolet wavelength range up to h(nu) about 35 eV on several atomic and molecular species, e.g., Ar, Kr, Xe, H2, N2, O2, CO, SO2, C2H2, C2N2, HCN, CH3CN, BF3, and SF6. Photoelectron branching ratios and angular distributions were obtained for all accessible states. A major emphasis of this work involved the initial exploration of novel effects of autoionization and shape resonances on alternative vibrational ionization channels. The second experimental approach entailed measuring the polarization of fluorescence following production of excited molecular ions by photoionization. This was also a novel experiment, allowing the direct measurement of the alignment of molecules ions produced by photoionization and, simultaneously, the branching ratios for degenerate photoelectron channels. The third experimental approach was, again, a novel experiment, and involved determining the photoelectron spectrum of an atomic cluster (Xe3) in a mixture of clusters formed in a supersonic expansion by the technique of photoion-photoelectron coincidence. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 06, 1981
- Accession Number
- ADA100863
Entities
People
- Albert C. Parr
- J. L. Dehmer
- Roger Stockbauer
Organizations
- National Institute of Standards and Technology