Accession Number:

ADA214026

Title:

Plasmon Excitation in the Scattering of Electromagnetic Waves from Good Conductors

Descriptive Note:

Final rept. 1 Oct 1988-1 Sep 1989

Corporate Author:

DAVID TAYLOR RESEARCH CENTER BETHESDA MD SHIP MATERIALS ENGINEERING DEPT

Personal Author(s):

Report Date:

1989-07-01

Pagination or Media Count:

19.0

Abstract:

Excellent Drude model fits were reported Kramers-Kroning analysis of measurements of the optical constants of 15 metals--Ti, Fe, Co, Ni, Pt, V, Pd, W, Pb, Cu, only provide excellent fits to the measured values of the conductivity but also were shown to predict the frequency dependence of the dielectric constant. All static values of the dielectric constant of these 15 metals were negative and very large, but increased monotonically with increasing frequency, passing through zero in the optical range between wavelengths of 1, 000 and 6,000A. This behavior was interpreted as plasmon excitation, and very sharply peaked loss factors were calculated. Furthermore, the novel behavior of the dielectric constant caused a large impedance discontinuity that kept the reflection coefficient very nearly equal to 1 unit until it dropped very rapidly at the plasma resonance frequency to values approaching zero as photon energies reached the electron volt range. Keywords Radar cross section Scattering Plasmon excitation Metals Electromagnetic waves Drude model Optical constants Plasma Dielectric constant Reflection.

Subject Categories:

  • Active and Passive Radar Detection and Equipment
  • Radiofrequency Wave Propagation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE