Patent Number: 
Section: claims

1. A non-resonance photo-neutralizer for neutral beam injectors comprisingfirst and second mirrors defining an open ended chamber, the first and second mirrors being spaced apart with opposing reflective surfaces and extending in a first direction between first and second ends of the open ended chamber, first ends of the first and second mirrors and seconds ends of the first and second mirrors being spaced apart and defining first and second openings at the first and second ends of the open ended chamber, the first mirror being concave along the first direction with the first and second ends of the first mirror being positioned closer to the second mirror than a central portion of the first mirror,wherein the first mirror is concave in a second direction transverse to the first direction. 2. The photo-neutralizer of claim 1 wherein a space interposing the first and second mirrors comprises a confinement region adjacent a family of normals common to the opposing reflective surfaces of the first and second mirrors. 3. The photo-neutralizer of claim 1 wherein a mirror surface of the first mirror is concave and a mirror surface of the second mirror is flat. 4. The photo-neutralizer of claim 1 wherein the first mirror comprises a mirror assembly including a central mirror and first and second outer mirrors coupled to the central mirror. 5. A non-resonance photo-neutralizer for neutral beam injectors comprisingfirst and second mirrors being spaced apart with opposing reflective surfaces and extending in a first direction, the first mirror being concave along the first direction with first and second ends of the first mirror being positioned closer to the second mirror than a central portion of the first mirror,wherein the first mirror comprises a mirror assembly including a central mirror and first and second outer mirrors coupled to the central mirror,wherein the central mirror is cylindrically shaped and the outer mirrors are conically shaped,wherein the first mirror is concave in a second direction transverse to the first direction. 6. A ion based neutral beam injector comprisinga negative ion source, anda non-resonance photo-neutralizer co-axially positioned with the ion source, wherein the photo-neutralizer including first and second mirrors defining an open ended chamber, the first and second mirrors being spaced apart with opposing reflective surfaces and extending in a first direction between first and second ends of the open ended chamber, first ends of the first and second mirrors and seconds ends of the first and second mirrors being spaced apart and defining first and second openings at the first and second ends of the open ended chamber, the first mirror being concave along the first direction with the first and second ends of the first mirror being positioned closer to the second mirror than a central portion of the first mirror, wherein the first mirror is concave in a second direction transverse to the first direction. 7. The neutral beam injector of claim 6 wherein a space between the first and second mirrors comprises a confinement region adjacent a family of normals common to the opposing reflective surfaces of the first and second mirrors. 8. The neutral beam injector of claim 6 wherein one or more of the mirror surfaces of the first and second mirrors are concave. 9. The photo-neutralizer of claim 6 wherein a mirror surface of the first mirror is concave and a mirror surface of the second mirror is flat. 10. The neutral beam injector of claim 6 wherein the first mirror comprises a mirror assembly including a central mirror and first and second outer mirrors coupled to the central mirror. 11. A ion based neutral beam injector comprisinga negative ion source, anda non-resonance photo-neutralizer co-axially positioned with the ion source, wherein the photo-neutralizer includingfirst and second mirrors being spaced apart with opposing reflective surfaces and extending in a first direction, the first mirror being concave along the first direction with first and second ends of the first mirror being positioned closer to the second mirror than a central portion of the first mirror,wherein the first mirror comprises a mirror assembly including a central mirror and first and second outer mirrors coupled to the central mirror,wherein the central mirror is cylindrically shaped and the outer mirrors are conically shaped,wherein the first mirror is concave in a second direction transverse to the first direction.