At https://www.hb11.energy/our-technology they list a number of papers they've published supporting their approach.
On ignoring the H B-11 reaction with high intensity lasers: https://www.nature.com/articles/ncomms3506
On the reaction avalanche: https://www.cambridge.org/core/journals/laser-and-particle-b...
On the conversion of alpha particles to electricity: https://www.cambridge.org/core/journals/laser-and-particle-b...