Abstract:
Thermionic cathode 12 for a plasma ion source 10 has tungsten wire 64 advanced by wheels 56 from supply 50 to take-up spool 58. In chamber 48, the active cathode region 64 acts with anode 16 to supply electrons for ionizing a fuel gas so the ions are discharged from slit 18 for acceleration, separation and implantation.
Abstract:
1. A rugged combustion-heated electron tube comprising: a metallic conica-shaped anode structure; a metallic conically-shaped cathode structure insulatedly and coaxially mounted in spaced relationship to said anode structure; a metallic conically-shaped grid structure insulatedly and coaxially mounted in spaced relationship between said anode structure and said cathode structure; first and second annular insulating spacer-seals separating said anode structure from said grid structure and said grid structure from said cathode structure, said spacer-seals in combination with said anode structure and said cathode structure providing a hermetically-sealed envelope containing said grid structure; and a combustible material mounted exteriorly of said envelope in proximity to said cathode structure, said combustible material being adapted to heat said cathode structure to an operating temperature.
Abstract:
The present invention relates to micro-cone targets for producing high energy and low divergence particle beams. In one embodiment, the micro-cone target includes a substantially cone-shaped body including an outer surface, an inner surface, a generally flat and round, open-ended base, and a tip defining an apex. The cone-shaped body tapers along its length from the generally flat and round, open-ended base to the tip defining the apex. In addition, the outer surface and the inner surface connect the base to the tip, and the tip curves inwardly to define an outer surface that is concave, which is bounded by a rim formed at a juncture where the outer surface meets the tip.
Abstract:
A thermionic electron emitter (1) is proposed comprising an inner part (2) including a heatable flat emission surface (3) and an outer part (4) including a surrounding surface (6) substantially enclosing the emission surface and a heating arrangement for heating the emission surface to a temperature for thermionic electron emission. The outer part is mechanically connected to the inner part in a connection region (10) apart from the emission surface. Furthermore, the surrounding surface is thermally isolated, e.g. by a gap (14), from the emission surface in an isolation region apart from the connection region. By providing a surrounding surface enclosing the emission surface which may be on a similar electrical potential as the emission surface but which can have a substantially lower temperature than the emission surface without influencing the temperature distribution within the emission surface, an improved electron emission distribution and homogeneity can be obtained.