Sa. Wymer et A. Lakhtakia, THE EXTINCTION EFFICIENCY OF A PERFECTLY CONDUCTING SPHERE EMBEDDED IN AN ABSORBING MEDIUM - THE ASYMPTOTIC VALUE, Journal of physics. D, Applied physics, 28(7), 1995, pp. 1285-1286
We have observed from numerical work that the extinction efficiency of
a perfectly conducting sphere goes to 2 as the size parameter increas
es, regardless of whether the embedding medium is absorbing or lossles
s.