Beam-Driven Sails and Divergence of Neutral Particle Beams

J. Benford (2017), JBIS, 70, pp.449-452

Refcode: 2017.70.449

Abstract:
One concept for a light interstellar probe is to accelerate it by a neutral particle beam. This paper considers whether that particle beam can be generated with the required properties. Unavoidable beam divergence, caused by the neutralization process, acting on a charged particle beam, makes the beam spot size much larger than the sail diameter. Divergence cannot be efficiently reduced by laser cooling. Consequently the neutral beam driven method can’t succeed due to beam divergence. However, fast interplanetary missions are more credible, enabling fast travel of small payloads around the Solar System. We give examples of neutral particle beam-driven sail probes.