Analysis of the Use of Different Backing Layer Materials in the Design of Alpha-Decay Sails for Interplanetary and Interstellar Travel

This paper analyzes the design of an alpha-decay sail. While previous studies have been conducted on the feasibility of alpha-decay sails, none have investigated the effects of different backing materials and backing material thicknesses on propulsion. This paper conducts simulations using the particle simulation toolkit Geant4 to determine the thrust produced from alpha-decay sails constructed of ²³⁸Pu and a backing layer made of aluminum, beryllium, lithium, or polyethylene. The results demonstrate that alpha-decay sails can be a very useful form of in-space propulsion, having the potential to dramatically decrease travel time beyond distances of 100 AU.