Patent ID: 7579780

Claim:
A power supply apparatus for controlling an ion accelerator that includes an anode electrode, a gas flow rate regulator and a magnetic field generating coil, the power supply apparatus comprising: a controller configured to control: an anode voltage applied to the anode electrode; a gas flow rate of gas flowing through the gas flow rate regulator; and magnetic flux density at an ion exit of the ion accelerator by controlling coil current flowing through the magnetic field generating coil, thereby adjusting magnitude of ion acceleration in the ion accelerator, wherein, based on: a sectional area of the ion exit of the ion accelerator; an ion accelerating region length of the ion accelerator; and a magnetic flux bias ratio indicating a ratio of the magnetic flux density at the ion exit to an average value of the magnetic flux density in an ion accelerating direction of the ion accelerator, the controller controls the anode voltage, the gas flow rate and the magnetic flux density at the ion exit that depends on the coil current, in order to satisfy a formula given as follows: 500 × 10 9 < β · V a · Q d · S · B 2 where S: sectional area of the ion exit [m 2 ]; d: ion accelerating region length [m]; β: magnetic flux bias ratio; Va: anode voltage [V]; Q: gas flow rate [sccm]; and B: magnetic flux density at the ion exit [T].