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-immersion ion implantation ( ~ l0 sec). Thus an ion matrix Debye sheath which is depleted of electrons forms around it. The negatively biased substrate will accelerate the ions within a time scale of the inverse ion plasma frequency ω ( ~ 10 sec). This ion movement lowers the ion density in the bulk, which causes the sheath-plasma boundary to expand in order to sustain the applied potential drop,in the process exposing more ions. The plasma sheath expands until either a steady-state condition is reached, which is called Child Langmuir law limit; or the high voltage is switched off as in the case