Patent ID: 8717733

Claim:
A method of converting a cloud of free electrons into negative ions within a corona discharge ionizer of the type having a through channel with a gas stream flowing therethrough, at least one ionizing electrode at least partially disposed within the gas stream and at least one reference electrode disposed on an exterior of the through channel and downstream of the ionizing electrode by a distance L, the method comprising: applying an ionizing signal, having a cycle T with positive and negative portions, to the ionizing electrode to thereby produce the electron cloud in the non-ionized gas stream, as the gas stream flows within the through channel, during a time Tnc of the negative portion of the ionizing signal, wherein the electron cloud moves downstream toward the exterior reference electrode and wherein the time Tnc is less than or equal to a time Te that it takes the electron cloud to move within the through channel distance L from the ionizing electrode to the exterior reference electrode; and detecting the negative corona onset voltage of the gas stream; maintaining the amplitude of the ionizing signal of the step of applying generally equal to the detected negative corona onset voltage; and inducing the electron cloud produced by the ionizing electrode to oscillate between the ionizing electrode and exterior reference electrode.