Arbitrarily Large Neutron Amplification in Subcritical Nuclear Reactors

In a subcritical reactor, each neutron produces only keff < 1 per generation (asymptotically and on average), thus the population decreases exponentially in absence of external source. The chain reaction is easy to stop, making such reactors inherently stable. Interestingly, contrary common wisdom, there no relation between keff, source intensity, output power reactor. this paper, I present various possible strategies exploit fact, apply them design rudimentary multi-layer system that allows reach an arbitrarily large number fissions neutron, while keeping fixed (I used keff=0.97). behavior amplifier verified with simple Monte-Carlo transport simulations. proposal admittedly brings complications subtleties need be studied further, but, if developed, could allow drive faint sources, e.g. radioisotope based.