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P C Waterman

Publications and source records attributed to P C Waterman.

2 recordsLinked to original sources

Scattering, absorption, and extinction by thin fibers.

For electromagnetic wave incidence on a thin fiber at an angle theta i with the fiber axis, induced currents are described by linear combinations of driven and traveling waves exp(+/-ikz cos theta i) and exp(+/-imkz), where the complex factor m serves to remove singularities in the normalizing constants of the currents. The fiber may be solid, hollow, or coated, with quite general constitutive parameters. Results are given for scattering, absorption, extinction, and radar cross sections, using energy conservation and reciprocity as consistency checks, and compared with independent computations, including the Born approximation for tenuous conductors and dielectrics. In addition, the far field amplitude of a 50 wavelength conductor is obtained and compared with the well-known long-wire approximation.

Journal Article↗

Isotropic scattering by penetrable cylinders.

Isotropic scattering is considered for infinite cylinders thin in the sense that ka << 1, although ¿k'a¿ and cross-sectional shape can be arbitrary within limits (k and k' are, respectively, free-space and interior propagation constants, and a is a characteristic dimension of the cylinder). For circular cylinders, scattering width is found to saturate at its perfectly conducting value, and absorption width is found to peak, when skin depth becomes comparable with cylinder diameter. For a variety of cylinders with and without edges, both scattering and absorption widths are then found to be effectively identical to those of the circular cylinder with equal cross-sectional area. A new analytical formula is obtained for high but not infinite conductivity, and the connection with scattering cross sections of corresponding finite cylinders is discussed.

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