Issue 10, March 2004

The First Announcement of the 8th Conference on Electromagnetic and Light Scattering by Nonspherical Particles, which will

be held in Salobreña, Granada, Spain, on May 16-20, next year is available on the following link:

http://www.iaa.csic.es/~confels8

Fernando Moreno, Instituto de Astrofisica de Andalucia, Granada, Spain

New papers on electromagnetic scattering

Lidar Backscatter Properties of Al₂O₃ Rocket Exhaust Particles

Robert A. Reed and Mitchel K. Nolen, ATA Inc., AEDC Group Arnold Air Force Base, TN 37389

Michael E. Zolensky, NASA Johnson Space Center

John Giles and Peter Lang, Johns Hopkins Univ. Applied Physics Lab

Michael I. Mishchenko, NASA Goddard Institute for Space Studies

Martin N. Ross, Aerospace Corp.

Abstract

The lidar backscatter cross sections of aluminum oxide rocket exhaust particles are sensitive to slight deviations from their nominal spherical shape. We have therefore determined

the distribution of particle shapes using automated image analysis of scanning electron microscope particle photographs. These shape statistics were used to in conjunction with

T-matrix calculations for nonspherical particles to estimate the backscatter properties of representative rocket exhaust particles. For the range of particle sizes and nonsphericities

relevant to exhaust plumes, both the backscatter intensity and depolarization scale approximately with the product of nonsphericity times the particle radius. This correlation allows

us to formulate a simple model for both the backscatter intensity and the depolarization of typical Al₂O₃ rocket exhaust particles. This model is applied to a recent particle collection

from the exhaust plume of a Titan-IVA rocket obtained from the NASA WB-57F high-altitude research aircraft at an altitude of 19 km.

Submitted to the AIAA J Spacecraft ad Rockets

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OPTICS OF COSMIC DUST. Part I

Nikolai V. VOSHCHINNIKOV

St. Petersburg University, Russia

The optics of small particles is useful in the interpretation of observational phenomena related to the extinction, scattering and emission of radiation by dust grains in space. Three

components of dust modeling - optical constants, light scattering theories and object' models - are briefly discussed. The author aims to show how the general laws of the optics

of dust particles work and to highlight the information about cosmic dust which is reliable and the information which can be false. Part I of the review contains a detailed

analysis of the interstellar extinction and polarization (forward-transmitted radiation).. Part II will consider the scattered radiation, dust absorption and emission, radiation pressure

and dust properties in different objects.

Astrophysics and Space Physics Reviews, v. 12, pp. 1--182, 2004

Figures 45, Tables 13, References 397

ISBN: 1-904868-23-1

Price: £~30.00, Euro 45.17, $55.18 plus postage

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