Underwater electrical wire explosion

The results of the investigation of the underwater electrical wire explosions using a high power sub-ns generator are reported. The spectroscopic analysis of the emitted radiation has unveiled no evidence for the formation of shunting plasma channel. The latter appears in vacuum and gas wire explosions and causes to the seizure of energy deposition into an exploding wire material. The combination of mechanism for the suppression of formation of shunting channel together with the increased energy deposition rate allows busting the efficiency of the energy deposition into the exploding wire. Estimated energy deposition into Cu and Al wire of up to 200 eV/atom was reported. Careful analysis of the generated shock waves show, that ∼15 % of the deposited energy is transferred into the mechanical energy of the generated water flow. In addition experiments with converging shock waves produced by underwater explosion of cylindrical wire arrays, the possibility of producing of shock waves with pressure amplitude up to 0.25 Mbar at 0.1 mm distance from the axis of the implosion was demonstrated. Results of a simplified model indicate that, using a spherical geometry setup with 7.5mm external radius of the water layer and ∼35kJ total deposited energy, 1.5·10¹⁴ neutron yield during ∼1.5ns time can be achieved. These results suggest that ignition of DT target by implosion in water medium can be considered as apromising method for inertial confinement fusion.