Ions pass through the Exit lens and move toward the MP00 ion optics, which are located between the API source interface and the MP0 ion optics. The MP00 ion optics include the MP00 RF rods and the L0 lens.
The MP00 RF rods are an array of four cylindrical metal elements. The MS applies an RF voltage to the elements, generating an electric field that guides the ions along the axis of the rods.
The L0 lens is a metal disk with a small hole in the center through which the ion beam passes. The MS applies an electrical potential to the L0 lens to transmit ions of the selected charge. The L0 lens, which mounts to the MP00 RF rods, also acts as a vacuum baffle between the MP00 ion optics chamber and the MP0 ion optics chamber.