These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Cavity ring-down spectroscopy measurements of single aerosol particle extinction. I. The effect of position of a particle within the laser beam on extinction.
    Author: Butler TJ, Miller JL, Orr-Ewing AJ.
    Journal: J Chem Phys; 2007 May 07; 126(17):174302. PubMed ID: 17492858.
    Abstract:
    A continuous wave distributed feedback diode laser operating in the near infrared at wavelengths close to 1650 nm has been used to measure the extinction of light by single aerosol particles. The technique of optical feedback cavity ring-down spectroscopy (CRDS) was used for measurement of CRDS events at a repetition rate of 1.25 kHz. This very high repetition rate enabled multiple measurements of the extinction of light by single aerosol particles for the first time and demonstrated the dependence of light scattering on the position of a particle within the laser beam. A model is proposed to explain quantitatively this phenomenon. The minimum detectable dimensionless extinction coefficient epsilonmin was determined to be 3x10(-6). Extinction values obtained for single spherical polymer beads from a monodisperse sample of particles of diameter of 4 microm are in near-quantitative agreement with the values calculated by the Mie scattering theory. The deviations from the Mie theory expected for measurement of extinction by CRDS using a continuous wave laser are discussed in the companion paper.
    [Abstract] [Full Text] [Related] [New Search]