FAST BURST AND STEADY-STATE INTENSE NEUTRON SOURCE
A first system for producing a high flux of neutrons for non-destructive testing includes a dense plasma focus device neutronically coupled to a subcritical or sub-prompt critical fission assembly. 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. A second system for producing a high flux of neutrons includes a gas-target neutron generator neutronically coupled to a subcritical or sub-prompt critical fission assembly. The gas-target neutron generator 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.
1 . A system for producing a flux of neutrons, the system comprising:
a dense plasma focus device having an input end and an output end;
a fission assembly neutronically coupled to the dense plasma focus device, the fission assembly is a subcritical or a sub-prompt critical fission assembly; and
a fast neutron multiplier layer configured to cover the output end of the dense plasma focus device,
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.
2 . The system of claim 1 , wherein the dense plasma focus device includes
a cylindrical cathode;
a cylindrical anode disposed within and concentric to the cathode; and
a chamber bounded by the cathode and the anode, the chamber being pressurized with a fill gas.
3 . The system of claim 2 , wherein the dense plasma focus device includes an insulator provided between the cathode and the anode, the insulator disposed proximate to the input end of the dense plasma focus device.
4 . The system of claim 2 , wherein the fill gas comprises a deuterium-tritium gas mixture.
5 . The system of claim 2 , wherein a pressure of the fill gas is static at 1-100 Torr.
6 . The system of claim 2 , further comprising a supply line configured to introduce puffs of the fill gas at pre-determined time intervals at the input end of the dense plasma focus device, wherein a pressure of the fill gas is dynamically raised at a pinch formed at a center of an end of the anode proximate to the output end of the dense plasma focus device.
7 . The system of claim 2 , wherein the anode has a radius of at least 20 cm and the cathode has a radius of at least 30 cm.
8 . The system of claim 1 , further including an outer multiplier layer configured to cover a sidewall and the input end of the dense plasma focus device.
9 . The system of claim 1 , wherein the outer multiplier layer is comprised of depleted uranium metal.
10 . The system of claim 1 , wherein the fission assembly comprises a low enriched uranium blanket.
11 . The system of claim 10 , wherein the fast neutron multiplier layer is positioned between the output end of the dense plasma focus device and the low enriched uranium blanket.
12 . The system of claim 1 , wherein the low enriched uranium blanket is configured to bound a test cavity.
13 . The system of claim 1 , wherein the dense plasma focus device further comprises a group of capacitor banks constructed in series.
14 . The system of claim 13 , wherein each capacitor bank is configured to individually discharge, and individual discharges of each of the capacitor banks are timed such that a specific pulse is formed in order to control a current drive time and a magnitude of current delivered to a pinch formed at a center of an end of an anode proximate to the output end of the dense plasma focus device.
15 . The system of claim 1 , wherein the fast neutron multiplier layer is comprised of an aluminum-beryllium alloy.
16 . The system of claim 1 , wherein the fission assembly further comprises a neutron reflector configured to surround the dense plasma focus device, an outer multiplier layer, the fast neutron multiplier layer and a low enriched uranium blanket.
17 . The system of claim 16 , wherein the neutron reflector is comprised of copper.
18 . The system of claim 1 , wherein the fission assembly is a subcritical fission assembly.
19 . The system of claim 1 , further including an outer multiplier layer configured to cover a sidewall and the input end of the dense plasma focus device; and wherein the fission assembly comprises a low enriched uranium blanket; the fast neutron multiplier layer is positioned between the output end of the dense plasma focus device and the low enriched uranium blanket.
20 . The system of claim 1 , wherein the dense plasma focus device includes
a cathode;
a anode disposed within the cathode;
an insulator provided between 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.