Plasma (Ionized gases) 31 Plasma Physics Physics 23 Astrophysics 9 Astrophysics and Astroparticles 7 Cosmology 5 Nuclear Energy 5 Nuclear energy 5 Biotechnology 4 Nuclear Engineering 4 Nuclear engineering 4 Astronomy 3 Coatings 3 Corrosion and anti-corrosives 3 Energy 3 Environmental Engineering/Biotechnology 3 Environmental engineering 3 Extraterrestrial Physics, Space Sciences 3 Force and energy 3 Materials Science 3 Materials science 3 Mathematical Methods in Physics 3 Particle Acceleration and Detection, Beam Physics 3 Particle acceleration 3 Power (Mechanics) 3 Power resources 3 Space sciences 3 Tribology 3 Tribology, Corrosion and Coatings 3 Adaptation (Biology) 2