Magnetic field fluctuation for beam smoothing

The time-averaged ion beam profile of an ion beam for implanting ions on a work piece may be smoothed to reduce noise, spikes, peaks, and the like and to improve dosage uniformity. Auxiliary magnetic field devices, such as electromagnets, may be located along an ion beam path and may be driven by periodic signals to generate a fluctuating magnetic field to smooth the ion beam profile (i.e., beam current density profile). The auxiliary magnetic field devices may be positioned outside the width and height of the ion beam, and may generate a non-uniform fluctuating magnetic field that may be strongest near the center of the ion beam where the highest concentration of ions may be positioned. The fluctuating magnetic field may cause the beam profile shape to change continuously, thereby averaging out noise over time.