Re: alkali or other hydrides. Do not assume classical "collisional" physics branching ratios--- many, or even all, of us likely do not actually understand the transition states / intermediate steps for the low activation energy paths and outcomes implied there.
Again, caution, small and shielded might be an important safety consideration--- A suddenly "successful" 1000 X (or far more) of peak power (whether alpha or not). Risky for unprepared amateurs or even unprepared professionals.
Think: 'unreported catastrophic "failures"'.