Abstract: A system for producing a localised concentration of energy from an input shockwave includes an amplifier arranged to manipulate one or more of the speed, pressure or shape of an input shockwave. The amplifier comprises a body of a first material, the body defining a cavity for manipulating the input shockwave to produce a manipulated shockwave. The cavity comprises an input for receiving the input shockwave incident upon the amplifier; and an output for outputting a manipulated shock-wave. The system further comprises a target configured to contain fuel, with the amplifier and the target being configured such that the manipulated shockwave is arranged to be output from the amplifier to be incident on the target.