Generation of converging strong shock wave formed by microsecond timescale underwater electrical explosion of spherical wire array

Abstract

A study of generation of converging strong shock wave using microsecond underwater electrical explosion of spherical Cu-wire array is presented. Hydrodynamic simulations coupled with the equation of state for Cu and water, deposited energy, and the magnetic pressure were used to calculate the water parameters in the vicinity of the implosion origin. The results of simulations agree with the shock wave time-of-flight and energy delivered to the water flow and show that in the vicinity (diameter of $12 lm) of an implosion one can expect water pressure of $6 TPa, temperature of $17 eV, and compression of $8. V C 2013 American Institute of Physics.

Spectroscopy of a plasma formed in the vicinity of implosion of the shock wave generated by underwater electrical explosion of spherical wire array

“…Thus, the spherical implosion of an SW allows one to obtain a ðr=r 0 Þ 0:66 larger pressure than does a cylindrical SW implosion for the same initial values of p 0 and r 0 . Indeed, experimental studies of the underwater electrical explosion of a spherical wire array 25,26 and numerical one-dimension HD simulations showed that in the vicinity of the implosion origin (r % 3 lm), one can expect to obtain in water P $ 6 Â 10 12 Pa, T $ 30 eV, and q $ 10 g/cm 3 . In these experiments, also the TOF of the SW to the origin of the implosion was measured.…”

Diagnostics of a converging strong shock wave generated by underwater explosion of spherical wire array

“…Indeed, only the last few tens of microns of spherical SW propagation in the vicinity of the converging origin were obtained by detecting intense light emission from that location, and these data were used as the TOF for comparison with the results of the 1D-HD simulations. 12,20 In the present experiments, we studied the dynamics of the convergence of the spherical SW using measurements of the change in the intensity of the CW laser beam (k ¼ 532 nm, 30 mW) guided by a lens to the input of the optical fiber. The fiber has a core diameter of 0.2 mm and it was covered by a non-transparent thin (0.25 lm) dielectric tube.…”

“…10 11 Pa during a short (in the range 10 À9 -10 À6 s) time duration. Recent research [10][11][12] showed that by using a pulsed power generator with stored energy of only a few kJ as a current source for the underwater electrical explosion of a wire array, one can generate WDM with P 6 Â 10 12 Pa. This method exploits the converging strong shock waves (SWs) generated by the underwater electrical explosion of either a cylindrical or a spherical wire array.…”

Shock wave convergence in water with parabolic wall boundaries

“…6 These approaches require expensive experimental setups with stored energy of !10 5 J. Recent experiments [7][8][9] with setups having moderate stored energy of 6 Â 10 3 J showed that extreme states of matter can be obtained using either underwater electrical explosion of single wires or converging shock waves (SW) generated by underwater electrical explosion of cylindrical or spherical wire arrays. In the case of the explosion of single wires in water, an energy density up to 500 eV/atom, pressure of $10 10 Pa, and temperature of a few eV were achieved inside the wires.…”

“…10 In the case of converging SW, the largest values of the pressure ( 6 Â 10 12 Pa), density ( 9 g/cm 3 ), and temperature ( 16 eV) of the water in the vicinity of the implosion were obtained for a spherical wire array explosion. 9 In these experiments, assuming spherical uniformity of the converging SW and self-similarity of the SW propagation in water, the value of pressure P SW versus the distance from the origin, i.e., radius R SW , increases as P SW / R À1:33 SW , due to fast decrease in the SW surface as S / R 2 SW : Mdivnishvili et al 11 suggested that using boundaries with a geometry providing faster decrease in the SW surface S / R 3 SW , the parameters (pressure, density, and temperature) of matter in the vicinity of the SW's convergence can be increased as compared with the case of a spherical SW implosion. Indeed, in the case of an adiabatic SW convergence, as the surface of the SW decreases faster, due to energy conservation, the energy density behind the SW front must also increase faster.…”