Methods of separating ionized particles comprise the step of providing a particle separator comprising a housing, and an electric field disposed inside the housing. The electric field defines a magnitude E (volt/cm) which increases the farther ionized particles travel within the housing. The method further includes delivering a gas flow, wherein the gas flow defines a velocity, Vgas, and delivering ionized particles into the housing, wherein the ionized particles define a mobility value, K (cm2/volt*sec). The product of the mobility value K and the electric field magnitude E define a mobility velocity for the ionized particles, Vmob (cm/sec)=K*E. The method also includes stopping the ionized particles at a location where Vmob is equal and opposite Vgas.