Multi-cusp ion source

An ion source including a plasma confinement chamber in which a plasma is generated and including a plasma electrode forming a wall section of the confinement chamber, the plasma electrode having at least one opening for allowing an ion beam to exit the confinement chamber, the improvement comprising:

• an insulator electrically insulating the plasma electrode from any other sections of the plasma confinement chamber,
• a power source electrically coupled between the other sections of the plasma confinement chamber and the plasma electrode, the power supply negatively biasing the plasma electrode relative to the other sections of the plasma confinement chamber
• a primary magnet coupled to the plasma electrode and having north and south poles that extend along a length of the magnet, said primary magnet being oriented to present one of said poles along an edge of the opening in the plasma electrode, and
• an opposing magnet coupled to the plasma electrode and having north and south poles that extend along a length of the magnet, said opposing magnet being oriented to present a pole opposite the pole of the primary magnet along an opposing edge of the opening in the plasma electrode such that a magnetic field extends across the opening in the plasma electrode through which the ion beam passes,
• wherein said primary magnet and the opposing magnet generate a magnetic field that extends over the openings in the plasma electrode through which the ion beam passes for filtering selected ions from the ion beam.

A plasma electrode for use in an ion source, the ion source including a plasma confinement chamber in which a plasma is generated and wherein the plasma electrode is adapted to form a wall section of the confinement chamber, the plasma electrode including at least one opening for allowing an ion beam to exit the confinement chamber, the electrode comprising:

• an insulator electrically insulating the plasma electrode from any other sections of the plasma confinement chamber,
• a power source electrically coupled between the other sections of the plasma confinement chamber and the plasma electrode, the power supply negatively biasing the plasma electrode relative to the other sections of the plasma confinement chamber
• a primary magnet coupled to the plasma electrode and oriented to present one pole along an edge of the opening in the plasma electrode, and
• an opposing magnet coupled to the plasma electrode and oriented to present an opposite pole along an opposing edge of the opening in the plasma electrode such that a magnetic field extends across the opening in the plasma electrode through which the ion beam passes,
• wherein said primary magnet and the opposing magnet generate a magnetic field that extends over the openings in the plasma electrode through which the ion beam passes for filtering selected ions from the ion beam.