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Journal of the Optical Society of America A

Journal of the Optical Society of America A

| OPTICS, IMAGE SCIENCE, AND VISION

  • Editor: Franco Gori
  • Vol. 30, Iss. 10 — Oct. 1, 2013
  • pp: 1947–1955

Internal fields of soot fractal aggregates

Matthew J. Berg and Christopher M. Sorensen  »View Author Affiliations


JOSA A, Vol. 30, Issue 10, pp. 1947-1955 (2013)
http://dx.doi.org/10.1364/JOSAA.30.001947


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Abstract

This work uses the discrete dipole approximation (DDA) to examine the internal electric field within a simulated carbon soot fractal aggregate in fixed and random orientations. For fixed orientations, deviations of the internal field magnitude up to ±50% from that assumed by the Rayleigh–Debye–Gans Approximation (RDGA) are found. Given the refractive index of the aggregate monomers and conditions for the validity of the approximation, such large deviations are no surprise. Yet despite this deviation, the far-field scattered intensity from such aggregates agrees surprisingly well with that described by the RDGA. Moreover, if the average over an ensemble of many random aggregate-orientations is calculated, both the DDA and RDGA scattered intensities obey the well-known power-law functionality in terms of the scattering wave vector and show a forward-angle intensity-maximum proportional to the square of the number of monomers. The explanation for this lies in the over and under estimations made by the approximation of the internal field, which apparently mostly cancel upon integration to yield the scattered intensity. It is shown that this error cancellation is related to the fractal structure of the aggregate and that the agreement between the DDA and RDGA improves with aggregates of increasing size provided the fractal dimension is less than two. Overall, the analysis suggests that both the special fractal character of the aggregate and its orientational averaging is important to account for the experimentally observed validity of the RDGA despite its poor description of the internal fields.

© 2013 Optical Society of America

OCIS Codes
(010.1110) Atmospheric and oceanic optics : Aerosols
(290.1090) Scattering : Aerosol and cloud effects
(290.5850) Scattering : Scattering, particles
(290.5890) Scattering : Scattering, stimulated
(290.5825) Scattering : Scattering theory
(290.5855) Scattering : Scattering, polarization

ToC Category:
Scattering

History
Original Manuscript: May 31, 2013
Revised Manuscript: August 12, 2013
Manuscript Accepted: August 13, 2013
Published: September 10, 2013

Citation
Matthew J. Berg and Christopher M. Sorensen, "Internal fields of soot fractal aggregates," J. Opt. Soc. Am. A 30, 1947-1955 (2013)
http://www.opticsinfobase.org/josaa/abstract.cfm?URI=josaa-30-10-1947


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References

  1. T. C. Bond and R. W. Bergstrom, “Light absorption by carbonaceous particles: an investigative review,” Aerosol Sci. Technol. 40, 27–67 (2006). [CrossRef]
  2. C. M. Sorensen, “Light scattering by fractal aggregates: a review,” Aerosol Sci. Technol. 35, 648–687 (2001). [CrossRef]
  3. L. Liu and M. I. Mishchenko, “Effects of aggregation on scattering and radiative properties of soot aerosols,” J. Geophys. Res. 110 D11211 (2005). [CrossRef]
  4. M. V. Berry and I. C. Percival, “Optics of fractal clusters such as smoke,” Opt. Acta 33, 577–591 (1986). [CrossRef]
  5. T. L. Farias, Ü. Ö. Köylü, and M. G. Carvalho, “Range of validity of the Rayleigh–Debye–Gans theory for optics of fractal aggregates,” Appl. Opt. 35, 6560–6567 (1996). [CrossRef]
  6. G. Wang and C. M. Sorensen, “Experimental test of the Rayleigh–Debye–Gans theory for light scattering by fractal aggregates,” Appl. Opt. 41, 4645–4651 (2002). [CrossRef]
  7. H. Y. Chen, M. F. Iskander, and J. E. Penner, “Light scattering and absorption by fractal agglomerates and coagulations of smoke,” J. Mod. Opt. 37, 171–181 (1990). [CrossRef]
  8. Y. Zhao and M. Lin, “Assessment of two fractal scattering models for the prediction of the optical characteristics of soot aggregates,” J. Quant. Spectrosc. Radiat. Transfer 110, 315–322 (2009). [CrossRef]
  9. R. Dhaubhadel, C. S. Gerving, A. Chakrabarti, and C. M. Sorensen, “Aerosol gelation: synthesis of a novel, lightweight, high specific surface area material,” Aerosol Sci. Technol. 41, 804–810 (2007). [CrossRef]
  10. F. G. Pierce, “Aggregation in colloids and aerosols,” Ph.D. dissertation (Kansas State University, Manhattan, Kansas, 2007).
  11. C. M. Sorensen and G. C. Roberts, “The prefactor of fractal aggregates,” J. Colloid Interface Sci. 186, 447–452 (1997). [CrossRef]
  12. S. P. Kearney and F. Pierce, “Evidence of soot superaggregates in a turbulent pool fire,” Combust. Flame 159, 3191–3198 (2012). [CrossRef]
  13. C. M. Sorensen, W. Kim, D. Fry, D. Shi, and A. Chakrabarti, “Observations of soot superaggregates with a fractal dimension of 2.6 in laminar acetylene/air diffusion flames,” Langmuir 19, 7560–7563 (2003). [CrossRef]
  14. R. Dhaubhadel, F. Pierce, A. Chakrabarti, and C. M. Sorensen, “Hybrid superaggregate morphology as a result of aggregation in a cluster-dense aerosol,” Phys. Rev. E 73, 011404 (2006). [CrossRef]
  15. A. M. Brasil, T. L. Farias, M. G. Carvalho, and U. O. Koylu, “Numerical characterization of the morphology of aggregated particles,” Aerosol Sci. Technol. 32, 489–508 (2001). [CrossRef]
  16. H. X. Zhang, C. M. Sorensen, E. R. Ramer, B. J. Olivier, and J. F. Merklin, “In situ optical structure factor measurement of an aggregating soot aerosol,” Langmuir 4, 867–871 (1988). [CrossRef]
  17. C. M. Sorensen, J. Cai, and N. Lu, “Light-scattering measurements of monomer size, monomers per aggregate, and fractal dimension for soot aggregates in flames,” Appl. Opt. 31, 6547–6557 (1992). [CrossRef]
  18. K. C. Smyth and C. R. Shaddix, “The elusive history of m=1.57−0.56i for the refractive index of soot,” Combust. Flame 107, 314–320 (1996). [CrossRef]
  19. C. F. Bohren and D. R. Huffman, Absorption and Scattering of Light by Small Particles (Wiley, 1998).
  20. M. I. Mishchenko, L. D. Travis, and A. A. Lacis, Scattering, Absorption, and Emission of Light by Small Particles (Cambridge University, 2002).
  21. M. A. Yurkin and A. G. Hoekstra, “The discrete dipole approximation: an overview and recent developments,” J. Quant. Spectrosc. Radiat. Transfer 106, 558–589 (2007). [CrossRef]
  22. M. J. Berg, “Power-law patterns in electromagnetic scattering: a selected review and recent progress,” J. Quant. Spectrosc. Radiat. Transfer 113, 2292–2309 (2012). [CrossRef]
  23. M. J. Berg, C. M. Sorensen, and A. Chakrabarti, “Reflection symmetry of a sphere’s internal field and its consequences on scattering: a microphysical approach,” J. Opt. Soc. Am. A 25, 98–107 (2008). [CrossRef]
  24. M. J. Berg, “Reflection symmetry of a sphere’s internal field and its consequences on scattering: behavior of the Stokes parameters,” in Polarimetric Detection, Characterization and Remote Sensing, M. I. Mishchenko, Y. S. Yatskiv, V. K. Rosenbush, and G. Videen, eds., NATO Science for Peace and Security Series C: Environmental Security (Springer, 2011), pp. 31–48.
  25. N. Lu and C. M. Sorensen, “Depolarized light scattering from fractal soot aggregates,” Phys. Rev. E 50, 3109 (1994). [CrossRef]
  26. M. Kerker, The Scattering of Light and Other Electromagnetic Radiation (Academic, 1969).
  27. N. G. Khlebtsov, “Optics of fractal clusters in the anomalous diffraction approximation,” J. Mod. Opt. 40, 2221–2235 (1993). [CrossRef]
  28. N. G. Khlebtsov and A. G. Melnikov, “Structure factor and exponent of scattering by polydisperse fractal colloidal aggregates,” J. Colloid Interface Sci. 163, 145–151 (1994). [CrossRef]
  29. M. I. Mishchenko, D. M. Mackowski, and L. D. Travis, “Scattering of light by bi-spheres with touching and separated components,” Appl. Opt. 34, 4589–4599 (1995). [CrossRef]
  30. D. M. Mackowski and M. I. Mishchenko, “Calculation of the T matrix and the scattering matrix for ensembles of spheres,” J. Opt. Soc. Am. A 13, 2266–2278 (1996). [CrossRef]

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