NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Radiation Pressure Measurements on Micron Size Individual Dust GrainsMeasurements of electromagnetic radiation pressure have been made on individual silica (SiO2) particles levitated in an electrodynamic balance. These measurements were made by inserting single charged particles of known diameter in the 0.2 micron to 6.82 micron range and irradiating them from above with laser radiation focused to beam-widths of approx. 175-400 micron, at ambient pressures approx. 10(exp -3) to 10(exp -4) torr. The downward displacement of the particle due to the radiation force is balanced by the electrostatic force indicated by the compensating dc potential applied to the balance electrodes, providing a direct measure of the radiation force on the levitated particle. Theoretical calculations of the radiation pressure with a least-squares fit to the measured data yield the radiation pressure efficiencies of the particles, and comparisons with Mie scattering theory calculations provide the imaginary part of the refractive index of silica and the corresponding extinction and scattering efficiencies.
Document ID
20030060660
Acquisition Source
Marshall Space Flight Center
Document Type
Preprint (Draft being sent to journal)
Authors
Abbas, M. M.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Craven, P.D.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Spann, J. F.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Tankosic, D.
(Alabama Univ. Huntsville, AL, United States)
Witherow, W. K.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
LeClair, A.
(Alabama Univ. Huntsville, AL, United States)
West, E.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Sheldon, R.
(Alabama Univ. Huntsville, AL, United States)
Gallagher, D. L.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Adrian, M. L.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
August 21, 2013
Publication Date
January 1, 2003
Subject Category
Physics (General)
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available