Usually, you want your flying vehicles to be extremely visible because you want other aircraft to know where you are using radar and other wavelengths of light. The exception is military aircraft, which very much don’t want to be seen, and so various technologies have been employed to reduce the reflection and emission of both light and sounds mostly in terms and materials and design. Scientists in China have proposed a new approach involving the fourth state of matter: plasma.
Plasma is actually the most common state of matter in the universe – it’s just a bit beyond our everyday experience of dealing with liquids, solids, and gases. But from stars to neon signs, plasma is everywhere. A substance is a plasma when it is ionized, at least some of its electrons are ripped from their atoms creating a medium full of unbound negative (the electrons) and positive (the atoms) particles.
It’s this partial ionization that matters to stealth technology. As the electromagnetic waves – in the case of radar, radio waves – propagate to the plasma, they move the charged particles about and deliver energy to them. So in principle, you could have a plasma that absorbs all of your radio waves. With nothing reflecting back, you’d be invisible to the radar.
There’s a vast gulf between the theory of such stealth technology and actual applications. However Chinese researchers including Tan Chang report that they are crossing that gulf, and they have a solution for this tech that might soon be applied to military aircraft. As reported by the South China Morning Post, Chang has claimed two approaches have been successfully tested.
One uses radioactive material in specific locations on the craft. As it decays, it ionizes the air, creating a plasma around it. The other uses electricity to ionize the air around the vehicle. The design is not intended to create plasma around the whole aircraft but only on specific portions that would give it away.
The team claims that the approaches allow for adapting them to many different aircraft designs and do not require the peculiar compromises of traditional stealth aircraft like the F-22 Raptor or the B-2 Spirit. Special shaping to reduce the so-called radar cross-section often has major aerodynamical drawbacks. Plasma could be a solution to this. Plasma stealth is also believed to have been used in Russian missiles 3M22 Zircon (SS-N-33) and Kh-47M2 Kinzhal.
LINK TO SOURCE: https://www.iflscience.com/china-has-designed-a-new-stealth-aircraft-that-uses-plasma-73044
