A system for producing a high flux of neutrons, the system comprising: a dense plasma focus device having an input end and an output end, the dense plasma focus device including: a cylindrical cathode; a cylindrical anode disposed within and concentric to the cathode; an insulator provided between portions of the cathode and the anode, the insulator disposed proximate to the input end of the dense plasma focus device; and a chamber bounded by the cathode and the anode, the chamber being pressurized with a fill gas, and a fission assembly neutronically coupled to the dense plasma focus device, wherein the fission assembly is a subcritical or a sub-prompt critical fission assembly, and wherein the dense plasma focus device is a source of initiating neutrons for the fission assembly, and the fission assembly is configured to multiply a number of the initiating neutrons via inducing fission, the system being characterised in that the fission assembly comprises: an outer multiplier layer configured to cover sidewalls and the input end of the chamber of the dense plasma focus device; a fast neutron multiplier layer configured to cover the output end of the chamber of the dense plasma focus device; a test cavity and a low enriched uranium blanket configured to bound the test cavity, wherein the fast neutron multiplier layer is sandwiched between the output end of the dense plasma focus device and the low enriched uranium blanket. a dense plasma focus device having an input end and an output end, the dense plasma focus device including: a cylindrical cathode; a cylindrical anode disposed within and concentric to the cathode; an insulator provided between portions of the cathode and the anode, the insulator disposed proximate to the input end of the dense plasma focus device; and a chamber bounded by the cathode and the anode, the chamber being pressurized with a fill gas, and a cylindrical cathode; a cylindrical anode disposed within and concentric to the cathode; an insulator provided between portions of the cathode and the anode, the insulator disposed proximate to the input end of the dense plasma focus device; and a chamber bounded by the cathode and the anode, the chamber being pressurized with a fill gas, and a fission assembly neutronically coupled to the dense plasma focus device, wherein the fission assembly is a subcritical or a sub-prompt critical fission assembly, and wherein the dense plasma focus device is a source of initiating neutrons for the fission assembly, and the fission assembly is configured to multiply a number of the initiating neutrons via inducing fission, the system being characterised in that the fission assembly comprises: an outer multiplier layer configured to cover sidewalls and the input end of the chamber of the dense plasma focus device; a fast neutron multiplier layer configured to cover the output end of the chamber of the dense plasma focus device; a test cavity and a low enriched uranium blanket configured to bound the test cavity, wherein the fast neutron multiplier layer is sandwiched between the output end of the dense plasma focus device and the low enriched uranium blanket. an outer multiplier layer configured to cover sidewalls and the input end of the chamber of the dense plasma focus device; a fast neutron multiplier layer configured to cover the output end of the chamber of the dense plasma focus device; a test cavity and a low enriched uranium blanket configured to bound the test cavity, wherein the fast neutron multiplier layer is sandwiched between the output end of the dense plasma focus device and the low enriched uranium blanket.