Generator for Producing High Concentrations of Small Ions

Abstract

An arrangement of a needle and a sonic orifice has been developed which is capable of converting the corona current into free small ions with 100% efficiency. Positive and negative ion concentrations of 10¹¹ ions/cm³ in the sonic jet and total ion outputs of 10¹⁴/sec have been achieved using 2.5 cfm of free air at 30 psig through a$\frac{1}{16}-\mathrm{in}$ . orifice. Theoretical and experimental studies of the ion decay rate in the jet show that the concentrations drop off approximately as the square of the distance from the ionizer.