Pulsed Liquid Metal Ion Source for Heavy Ion Fusion

75488-Pulsed ion sources are used in a variety of applications from heavy ion fusion to space propulsion. In order to optimize the ion beams that are produced, it is necessary to have a very high degree of reproducibility from pulse to pulse. Liquid metal ion sources have been shown to provide beams with extremely low noise and no significant charge state variation; however, the useful emitter current is very limited, and no reliable data for pulsed operation exist. This project will develop an innovative approach to pulsed operation with liquid metal ion sources using low voltage pulses. In Phase I, beam current will be increased by increasing the number of emitters, while keeping the footprint small through micro-machining technology. 0.5A of beam current will be extracted from 50000 pixels, each operating at 10¿A over an area less than 10cm2. A 2 x 2 emitter array will be built using liquid metal ion sources. Pulsed operation will be demonstrated, and key beam parameters (charge state, mass efficiency) will be determined. Commercial Applications and Other Benefits as described by the awardee: In addition to the application to heavy ion fusion, pulsed liquid metal ion sources, which produce high ion velocities (greater than 100km/s), could be used for (1) energetic deposition applications, where the increased velocity translates into significant penetration into the substrate material, providing a strong bond between the coating and substrate; and (2) space propulsion, in which the liquid metal ion sources could be utilized for extended duration missions, due to the high exhaust velocity, and for fine positioning with very small fluctuations.