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The Influence of Laser Radiation on an Absorbing Aerosol

Published online by Cambridge University Press:  21 February 2011

T.F. Morse
Affiliation:
Brown University, Providence, R.I.02912
D. DiGiovanni
Affiliation:
Brown University, Providence, R.I.02912
J.W. Cipolla Jr
Affiliation:
Northeastern University, Boston, Mass. 02115
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Abstract

When aerosol particles are immersed in a gas in which a temperature gradient is present, a force proportional to this gradient moves these particles toward the lower temperature. This is the thermophoretic force.It is responsible for the deposition of aerosol particles in processes employed in the manufacture of gradient index silicon dioxide, germanium dioxide optical fiber preforms.The deposition efficiency is approximately 50%, and in order to increase this efficiency, we have examined the interaction of an absorbing silicon dioxide aerosol with carbon dioxide laser radiation.The resulting temperature profile mirrors the intensity distribution, since the aerosol temperature is proportional to the local laser intensity.The absorbed radiation thus creates a temperature gradient that results in additional thermophoretic and convective motion. A simple model of laser-induced buoyant convection and thermophoresis is presented, and it is shown how deposition efficiency can be increased with laser radiation.Theoretical and preliminary experimental results are discussed.

Type
Research Article
Copyright
Copyright © Materials Research Society 1984

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References

REFERENCES

1. Nagel, S., MacChesney, J.B., and Walker, Kenneth, J.Quant.Electronics, vol.QE-18, no.4, April 1982, p.459.Google Scholar
2. Simpkins, P.G., Greenberg-Kosinski, S, and MacChesney, J.B., J.Appl.Phys., 50, p.5767 (1979).Google Scholar
3. Walker, K.L., Geyling, F.T., and Nagel, S.R., J.Am.Ceramic Soc., vol.63, p.552, (1980).CrossRefGoogle Scholar
4. Walker, K.L., Homsy, G.M., and Geyling, F.T., J.Colloid.Interface.Sci.,69, p.138, (1979).CrossRefGoogle Scholar
5. The Winter 1980 issue of The Western Electric Engineer is completely devoted to various aspects of optical fibers, and is a good introductory reference.Google Scholar
6. N.A.Fuchs, The Mechanics of Aerosols, The MacMillan Co., New York, 1904.Google Scholar
7. Hidy, G.M. and Brock, J.R., The Dynamics of Aerocolloidal Systems, International Reviews in Aerosol Physics and Chemistry, vol.1, Pergamon Press, N.Y., 1971.Google Scholar
8. Mie, Gustav, Physik, Ann. d., vierte Folge, Band 25, 1908, p. 377.Google Scholar
9. Gaskell, P.H., and Johnson, D.W., J. Non-Crystall. Solids, p. 153169, 1976.Google Scholar
10. Morse, T.F., and Cipolla, J.W. Jr., “Laser Modification of Thermophoretic Deposition”, J.Colloid. Interface.Sci., vol.97, No.1, Jan 1984, p.137.Google Scholar
10a. See also “Heat Transfer and Thermophoresis in an Absorbing Aerosol” presented at 20th National Heat Transfer Conference, Seattle, Wa. 1983, ASME paper no. HT-83-55.Google Scholar
11. Girardin, D., Streesing, N., Cipolla, J.W. Jr., and Morse, T.F., “One Dimensional Unsteady Thermophoretic Motion”, presented at the ASME winter annual meeting, Boston, Ma., Nov.1983.Google Scholar
12. Wang, C.Y., Morse, T.F., and Cipolla, J.W. Jr., “Laser Induced Natural Convection and Thermophoresis”, J. Heat Transfer, to appear.Google Scholar
13. Wang, C.Y., Morse, T.F., and Cipolla, J.W. Jr., “Laser Induced Thermophoresis and Particulate Deposition Efficiency”, J. Heat Transfer, to appear.Google Scholar
14. Weinberg, M.C. and Subramanian, R.S., J.Coll.Interface.Sci., vol.87, 1982, p.579.Google Scholar
15. Weinberg, M.C., J.Am.Ceramic Soc., vol.65, 1982, p.81,Google Scholar
16. Weinberg, M.C., J.Colloid. and Interface. Sci., vol. 84, 1981, p.550.Google Scholar