کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5428605 1508684 2013 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Minimum principles in electromagnetic scattering by small aspherical particles
ترجمه فارسی عنوان
حداقل اصول در پراکندگی الکترومغناطیسی توسط ذرات کوچک کسر
کلمات کلیدی
پراکندگی الکترومغناطیسی، شکل ذرات، حداقل اصول،
موضوعات مرتبط
مهندسی و علوم پایه شیمی طیف سنجی
چکیده انگلیسی


- Particle shape for minimal extinction for low and high frequency scattering is a sphere.
- Proof of spherical optimality is extended to coated spheroids.
- Electric and geometric contributions are separated in the Rayleigh-Gans region.
- Bridging the low- and high-frequency regions is proposed.

We consider the question of optimal shapes, e.g., those causing minimal extinction among all shapes of equal volume. Guided by the isoperimetric property of a sphere, relevant in the geometrical optics limit of scattering by large particles, we examine an analogous question in the low frequency approximation, seeking to disentangle electric and geometric contributions. To that end, we survey the literature on shape functionals and focus on ellipsoids, giving a simple discussion of spherical optimality for the coated ellipsoidal particle. Monotonic increase with asphericity in the low frequency regime for orientation-averaged induced dipole moments and scattering cross-sections is also shown. Additional physical insight is obtained from the Rayleigh-Gans (transparent) limit and eccentricity expansions. We propose connecting low and high frequency regimes in a single minimum principle valid for all size parameters, provided that reasonable size distributions of randomly oriented aspherical particles wash out the resonances for intermediate size parameters. This proposal is further supported by the sum rule for integrated extinction.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Quantitative Spectroscopy and Radiative Transfer - Volume 131, December 2013, Pages 194-201
نویسندگان
, ,