title: Approximations to extinction from randomly oriented circular and elliptical cylinders.
abstract: Analytic approximations to the extinction efficiency, Qext, are given for oriented and randomly oriented circular infinite cylinders based on anomalous diffraction. The results are compared with the exact code. These results are further generalized to randomly oriented elliptical cylinders. With the use of the formulas, Qext can be evaluated over 10(4) times faster than with the exact code. This approximation is valid for complex refractive indices m = n - ik, where 1 ≤ n ≤ ∞ and 0≤ k ≤ 3, aspect ratios from 1 to 4, and modest to large particle sizes. The accuracy and limitations of these formulas are discussed.
authors.forename: G R
authors.initials: GR
authors.lastname: Fournier
authors.forename: B T
authors.initials: BT
authors.lastname: Evans