The basic concept and the main practical considerations of an Energy Amplifier (EA) have been exhaustively described in Ref. . Here the concept of the EA is further explored and additional schemes are described which offer a higher gain, a larger maximum power density and an extended burn‐up. All these benefits stem from the use of fast neutrons, instead of thermal or epithermal ones, which was the case in Ref. . The higher gain is due both to a more efficient high energy target configuration and to a larger, practical value of the multiplication factor. The higher power density results from the higher permissible neutron flux, which in turn is related to the reduced rate of 233Pa neutron captures (which, as is well known, suppress the formation of the fissile 233U fuel) and the much smaller k variations after switch‐off due to 233Pa decays for a given burn‐up rate. Finally a longer integrated burn‐up is made possible by reduced capture rate by fission fragments of fast neutrons. In practice a 20 MW proton beam (20 mA @ 1 GeV) accelerated by a cyclotron will suffice to operate a compact EA at the level of ≊1 GWe. The integrated fuel burn‐up can be extended in excess of 100 GW d/ton, limited by the mechanical survival of the fuel elements. Radio‐Toxicity accumulated at the end of the cycle is found to be largely inferior to the one of an ordinary Reactor for the same energy produced. Schemes are proposed which make a ‘‘melt‐down’’ virtually impossible. The conversion ratio, namely the rate of production of 233U relative to consumption is generally larger than unity, which permits production of fuel for other uses. Alternatively the neutron excess can be used to transform unwanted ‘‘ashes’’ into more acceptable elements.