The invention comprises a negative ion source method and apparatus used as part of an ion beam injection system, which is used in conjunction with multi-axis charged particle or proton beam radiation therapy of cancerous tumors. The negative ion source preferably includes an inlet port for injection of hydrogen gas into a high temperature plasma chamber. In one embodiment, the plasma chamber includes a magnetic material, which provides a magnetic field barrier between the high temperature plasma chamber and a low temperature plasma region on the opposite side of the magnetic field barrier. An extraction pulse is applied to a negative ion extraction electrode to pull the negative ion beam into a negative ion beam path, which proceeds through a first partial vacuum system, through an ion beam focusing system, into the tandem accelerator, and into a synchrotron.