A calculation procedure for 2D simulation of toner particle movement between a cylindrical OPC and a cylindrical developer in the presence of an AC bias is presented. The potential between two flat surfaces is calculated using the finite element method with its initial potential analytically calculated incorporating contributions from toner particles whose internal charge distribution is approximated with a cosine pulse. The flat surface potential is then transformed into the physical geometry using conformal mapping techniques and the corresponding electric field is obtained by interpolating the potential and taking its spatial differences. Toner movement between the two rotating, cylindrical surfaces due to the force field is calculated using the discrete element method.Simulated particle movement data using various line widths and AC bias settings are analyzed to qualitatively explain developed line width gain variations. Simulated single line development shows a larger line width gain than thicker lines. It is observed that particle movement around the exposed region begins to stabilize at a certain rotation angle of the exposed region, which appears to be correlated with the input line width dependent line width gain variation. An increase in AC bias magnitude and a decrease in AC bias frequency tend to exacerbate the line width gain variation.