Plasma Tubes Intercept Micorwave Radiation Independent of Polarization

Summary form only given. We have been designing a plasma shield intended to protect sensitive microwave equipment from intense electronic warfare signals. A layer of plasma tubes is used as a microwave reflector. The plasma tubes work extremely well in intercepting microwave radiation when the incident wave electric field is parallel to the tubes. However, if the electric field is perpendicular to the tubes, the normally induced plasma current cannot flow, and the plasma effects are not expected to appear. To our surprise, when the plasma tubes were experimentally tested with the electric field perpendicular to the tubes, the plasma tubes not only intercepted the microwave signal, but the observed cut-off with a pulsed plasma lasted about twice as long. The effect appears to be due to an electrostatic resonance, and preliminary calculations suggest that a normally ignored term in Maxwell´s equations is responsible. nabla²E - nabla(nablaldrE) = mu₀epsiv₀(omega_p ² + part²E/partt²). The term responsible appears to be nabla(nablaldrE).The frequencies involved are in the range of 2.5 GHz. The plasma tubes used are conventional fluorescent lamps. In any event, regardless of the theory, the experimental results demonstrate that shielding a sensitive receiving antenna by a layer of parallel plasma tubes is considerably more effective than had been expected.