Abstract
The size parameter spacing Δx between an1 and an+11 or between bn1 and bn+11 resonances have been derived to be Δx = x arctan [(mx/n)2 − 1]1/2/n[(mx/n)2 − 1]1/2. Comparison with numerical calculation of the position of resonances in Mie scattering suggests that the accuracy of the derived expression is near 1%.