Plasma stealth

Plasma stealth is a proposed process to use ionized gas (plasma) to reduce the radar cross-section (RCS) of an aircraft. Interactions between electromagnetic radiation and ionized gas have been extensively studied for many purposes, including concealing aircraft from radar as stealth technology. Various methods might plausibly be able to form a layer or cloud of plasma around a vehicle to deflect or absorb radar, from simpler electrostatic or radio frequency discharges to more complex laser discharges. It is theoretically possible to reduce RCS in this way, but it may be very difficult to do so in practice. Some Russian systems e.g. the 3M22 Zircon (SS-N-33) missile have been reported to make use of plasma stealth. Plasma stealth is a proposed process to use ionized gas (plasma) to reduce the radar cross-section (RCS) of an aircraft. Interactions between electromagnetic radiation and ionized gas have been extensively studied for many purposes, including concealing aircraft from radar as stealth technology. Various methods might plausibly be able to form a layer or cloud of plasma around a vehicle to deflect or absorb radar, from simpler electrostatic or radio frequency discharges to more complex laser discharges. It is theoretically possible to reduce RCS in this way, but it may be very difficult to do so in practice. Some Russian systems e.g. the 3M22 Zircon (SS-N-33) missile have been reported to make use of plasma stealth. In 1956, Arnold Eldredge, of General Electric, filed a patent application for an 'Object Camouflage Method and Apparatus,' which proposed using a particle accelerator in an aircraft to create a cloud of ionization that would '...refract or absorb incident radar beams.' It is unclear who funded this work or whether it was prototyped and tested. U.S. Patent 3,127,608 was granted in 1964. During Project OXCART, the operation of the Lockheed A-12 reconnaissance aircraft, the CIA funded an attempt to reduce the RCS of the A-12's inlet cones. Known as Project KEMPSTER, this used an electron beam generator to create a cloud of ionization in front of each inlet. The system was flight tested but was never deployed on operational A-12s or SR-71s. In 1992, Hughes Research Laboratory conducted a research project to study electromagnetic wave propagation in unmagnetized plasma. A series of high voltage spark gaps were used to generate UV radiation, which creates plasma via photoionization in a waveguide. Plasma filled missile radome were tested in an anechoic chamber for attenuation of reflection. At about the same time, R. J. Vidmar study the use of atmospheric pressure plasma as electromagnetic reflectors and absorbers. Other investigators also studied the case of a non-uniform magnetized plasma slab. Despite the apparent technical difficulty of designing a plasma stealth device for combat aircraft, there are claims that a system was offered for export by Russia in 1999. In January 1999, the Russian ITAR-TASS news agency published an interview with Doctor Anatoliy Koroteyev, the director of the Keldysh Research Center (FKA Scientific Research Institute for Thermal Processes), who talked about the plasma stealth device developed by his organization. The claim was particularly interesting in light of the solid scientific reputation of Dr. Koroteyev and the Institute for Thermal Processes, which is one of the top scientific research organizations in the world in the field of fundamental physics. The Journal of Electronic Defense reported that 'plasma-cloud-generation technology for stealth applications' developed in Russia reduces an aircraft's RCS by a factor of 100 (20 dB). According to this June 2002 article, the Russian plasma stealth device has been tested aboard a Sukhoi Su-27IB fighter-bomber. The Journal also reported that similar research into applications of plasma for RCS reduction is being carried out by Accurate Automation Corporation (Chattanooga, Tennessee) and Old Dominion University (Norfolk, Virginia) in the U.S.; and by Dassault Aviation (Saint-Cloud, France) and Thales (Paris, France). A plasma is a quasineutral (total electrical charge is close to zero) mix of ions (atoms which have been ionized, and therefore possess a net positive charge), electrons, and neutral particles (un-ionized atoms or molecules). Most plasmas are only partially ionized, in fact, the ionization degree of common plasma devices like fluorescent lamp is fairly low ( less than 1%). Almost all the matter in the universe is very low density plasma: solids, liquids and gases are uncommon away from planetary bodies. Plasmas have many technological applications, from fluorescent lighting to plasma processing for semiconductor manufacture.