US Patent 7796727 Aerosol charge conditioner

An attenuated soft x-ray neutralizer for neutralizing aerosols. The apparatus includes a soft x-ray emitter that emits soft x-rays into an aerosol conditioning chamber. An attenuating window may be included that reduces the intensity of the soft x-rays that bombard the aerosol, thus generating fewer radiolytically generated particles. Another way to reduce or control the intensity of the soft x-rays is to control emission of the cathode in the soft x-ray emitter. The reduced intensity of the soft x-rays was found by experiment to satisfactorily condition an aerosol stream without substantial radiolytic generation of particles precipitation.