Ion beam extraction apparatus and method for creating an ion beam

An ion beam extraction apparatus, being configured for creating an ion beam, comprising

• an ion source device being arranged for creating ions, and
• a grid device comprising at least two grids including:
• a plasma grid arranged next to the ion source device and being the first grid passed by the ions created by the ion source device, and
• an extraction grid arranged adjacent to the plasma grid,
• said at least two grids being arranged adjacent to the ion source device and having a mutual grid distance along a beam axis, wherein
• the grids are electrically insulated relative to each other,
• the grids are arranged for applying different electrical potentials for creating an ion extraction and acceleration field along the beam axis, and
• the ion source device and the grid device are arranged in an evacuable ion beam space extending along the beam axis, wherein
• the plasma grid is a movable grid, which can be shifted along the beam axis,
• the extraction grid has a fixed distance from the ion source device,
• the grid device is coupled with a grid drive device, and
• the grid drive device comprises a drive motor, which is arranged for moving the plasma grid along the beam axis and setting the mutual grid distance between the plasma grid and the extraction grid, and
• a cooling device with cooling medium supply lines coupled to the grids and arranged for cooling the grid device.