Patent ID: 8183539

Claim:
A magnet system with high mass resolution and low aberration for mass analyzing the ribbon shaped ion beam comprising of: two planner magnet poles; two field clamps, connects to the magnet poles; two planner coils, each wound around a magnet pole, the path of the coil mainly follows the boundary of the magnet pole; the coil connects to the electrical power supply to produce the magnetic field in the spatial region between the two magnet poles; a return yoke connects the two planner magnet poles; a mass resolving aperture which is inside the spatial region between the two magnet poles to selectively pass only ions of the desired mass; and the said magnet is in substantial mirror symmetry to its mid-plane with one magnet pole, with one coil and one field clamp on each side; and the said spatial region between the two magnet poles serves as a spatial passageway for the traveling ion beam; and the said ribbon beam goes into the passageway of the magnet from the entrance end, the ribbon ion beam forms a focal spot in the middle of the passageway, the ribbon beam goes out of the passageway from the exit end.