Energetic neutral atom Energetic neutral atom Energetic neutral atom (ENA) imaging, often described as "seeing with atoms", is a technology used to create global images of otherwise invisible phenomena in the magnetospheres of planets and throughout the heliosphere, even to its outer boundary. This constitutes the far-flung edge of the solar system. The solar wind consists of ripped-apart atoms (called plasma) flying out of the Sun. This is mostly hydrogen, that is, bare electrons and protons, with a little bit of other kinds of nuclei, mostly helium. The space between solar systems is similar, but they come from other stars in our galaxy.
Plasma antenna in reducing the cost of vehicle-mounted radar collision avoidance systems. In an ionized gas plasma antenna, a gas is ionized to create a plasma. Unlike gases, plasmas have very high electrical conductivity so it is possible for radio frequency signals to travel through them so that they act as a driven element (such as a dipole antenna) to radiate radio waves, or to receive them. Alternatively the plasma can be used as a reflector or a lens to guide and focus radio waves from another source. Solid-state antennas differ in that the plasma is created from electrons generated by activating