Thermo-accelerative optimization of relativistic lightsails

2021 
The Breakthrough Starshot Initiative aims to send a gram-scale probe to Proxima Centuri B using a high-power laser-accelerated lightsail traveling at relativistic speeds. Thermal degradation is a key consideration in the design of lightsails because the intense laser power required will heat sails to extreme temperatures. Previous work has evaluated lightsails primarily based on their acceleration distance, with thermal considerations being a secondary concern. In this work, we demonstrate co-optimization of accelerative and thermal performance for sail designs that use a multilayer connected photonic crystal composed of layered 2H-phase Molybdenum Disulfide and crystalline Silicon Nitride. We highlight the inverse relationship between thermal band extinction coefficient and lightsail maximum steady state temperature, then characterize the trade-off between acceleration distance and maximum sail temperature. Additionally, we introduce thermally endurable acceleration minimum (TEAM) as a summary result that characterizes the best realistic acceleration distance achievable within a sail design space, and report a TEAM value of 16.2 Gm for our class of designs. We conclude by demonstrating a multiscale Mie resonance-based approach to enhancing sail emissivity over infrared wavelengths that simultaneously preserves favorable lightsail acceleration distance characteristics.
    • Correction
    • Source
    • Cite
    • Save
    • Machine Reading By IdeaReader
    43
    References
    0
    Citations
    NaN
    KQI
    []