Double Absorption Photofragment Spectroscopy, A New Tool for Probing Unimolecular Process,

Abstract

A new technique, Double Absorption Photofragment Spectroscopy (DAPS), has been developed for observing the time evolution of unimolecular processes. Molecules isolated from collisions in a molecular beam are prepared in a well defined intermediate state by an initiation laser pulse. As this state evolves in time, it is monitored by a second probe laser pulse which, after a chosen delay, photodissociates the molecules. Information about the state to which the molecules have evolved by the time of the probe pulse can be extracted from the mass, density, angular and energy distributions of the recoiling fragments. Simple models are explored for the functional form of the angular distributions which can be expected in DAPS experiments. Future DAPS experiments should be able to observe unimolecular electronic and nuclear change over a time span from 10 to the -12th power to 10 to the -3rd power seconds, probing such processes as rearrangement, dissociation, internal vibrational transfer, intersystem crossing and internal conversion.

Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1974
Accession Number
ADA002228

Entities

People

  • K. R. Wilson
  • R. K. Sander

Organizations

  • University of California, San Diego

Tags

Communities of Interest

  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Absorption
  • Collisions
  • Conversion
  • Crossings
  • Dissociation
  • Internal Conversion
  • Laser Pulses
  • Molecular Beams
  • Molecules
  • Personal Information Managers
  • Photofragment Spectroscopy
  • Spectroscopy

Fields of Study

  • Physics

Readers

  • Positioning, Navigation, and Timing (PNT) Technology.
  • Quantum Chemistry
  • Solar Physics

Technology Areas

  • Directed Energy
  • Microelectronics