Radar Screening using Weakly Ionised Plasmas
J M Blackledge, Dublin Institute of Technology, Ireland

Since its original development in the late 1930s, Radio Detection and Ranging or Radar has been used for many years to detect airborne objects using ground and/or airborne platforms. The use of stealth technology for suppressing the detection of aerospace vehicles by Radar has been the subject of intensive research since the early 1970s following the development of radar guided surface-to-air missiles in the 1960s. Based on ideas first introduced in 1974 at Lockhead's advanced engineering laboratories, the technology is based on two principal aspects: (i) design features; (ii) advanced radar absorbing materials and coatings.

This paper explores another complementary technology based on attempting to cloak an aerospace vehicle in a weakly ionised plasma cloud. For weakly ionized plasmas, the conductivity is determined by the number density of electrons. Based on this result, a model is developed for electron beam induced plasmas that includes the effect of cascade ionization and losses due to diffusion and recombination. Qualitative results are then derived for the number density of a plasma screen over a sub-sonic and super-sonic aerospace vehicle.