ion recombinationion repellerion sheathion source ion gunion spotion trapion trap maganet beam benderion yieldionicionic heated cathodeionic impurityionizationionization by collisionionization energyionization levelionization path ionization trackionization potentialionization timeionization voltage electron binding energyionized layerionizing eventionizing particleionizing radiationionosphereionospheric errorionospheric scatterionospheric stormipir drop resistance dropirbmirdomeirediridiumiris diaphragmiris matching diaphragmironiron cobalt alloyiron coreiron core coiliron core coil iron core chokeiron core transformeriron lossiron nickel alloyiron vane instrumentirrationalirregularirregular fromirregularityirreversibleirreversible process