Curved-Field Plasma Transmission into a Mirror Machine

Plasma from an occluded-gas hydrogenated titanium-washer source was transmitted into a mirror machine along the field lines of a magnetic cusp formed at one end of the system. The results are compared with those produced by an identical gun located at a mirror on the magnet coil axis. Measurements indicate that in low magnetic fields, heavy ions strike the walls, producing neutrals that are subsequently excited and ionized by the contained plasma. At high magnetic fields (∼6 kG at the mirrors), all ions appear to turn the corner but a radial profile of the ion density is asymmetric. A peak density of 1 × 1013 H ions/cm3 is indicated near the mirror axis, agreeing with the results found by other investigators with toroidal or double-bend magnetic field geometries.