“…Figure presents a sectional view of the simulated electrodes, the potential contours, and the ion trajectories in the region of the duplex MALDI source. The initial kinetic energy of the ions in the + z direction was defined by the empirical results in the literature. − Since no additional focusing device is installed in the field-free drift tubes, the configuration of the duplex source exhibits many unique features for optimizing the transmission efficiency, reducing the beam divergence, and extending the mass working range. According to the predictions for the current configuration, the appropriate initial ionic energy is below 5 eV; for ions of higher initial energy, such as heavy biomolecules, a higher extraction potential is recommended.…”