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Based on high pulsed power technology, electrical explosion is increasingly utilized to generate shock waves with high pressure. To further magnify the shock wave pressure, we have proposed a novel technique by using energetic materials ignited by the plasma of microsecond wire explosion. Organic derivatives of nitramide, termed nitroamines, are widely used as powerful and relatively insensitive explosives. In this paper, we investigated the shockwave characteristics of nitramine (RDX and HMX) powders ignited by exploding copper wire (diameter 0.3 mm and length 60 mm). With charge voltage of 24 kV and powder mass about 6.0 g, the most evident experimental results suggested that the RDX load possessed higher peak pressure of 11.38 MPa and larger areal impulse of 503.02 MPa $\cdot \mu \text{s}$ , comparing with the shock wave of HMX load (7.22 MPa and 371.28 MPa $\cdot \mu \text{s}$ ). Moreover, the RDX load also had greater ascent rate of pressure, which was nearly twofold of that of the HMX load. Finally, a simple multi-factor ignition mechanism for nitramine powder under microsecond exploding wire plasma was proposed and discussed.

Based on high pulsed-power technology, electrical explosion is increasingly utilized to generate shock waves (SWs) with high pressure and short duration. To further magnify the SWs, we have proposed a novel technique by using energetic material (EM) loads. In this paper, we investigated the SW characteristics of ammonium nitrate (AN) powders ignited by the plasma of different kinds of refractory wire explosion. Evident results suggested that compared with $\Phi ~0.5$ -mm wires, $\Phi ~0.2$ -mm molybdenum and tantalum wires were able to finish vaporization, undergo the breakdown and eventually produce stronger SWs. After introducing the AN powders, the peak pressure of SW was scarcely enhanced, while the duration was significantly increased. Moreover, it was implied that various factors would affect the SW characteristics, including the EM charge density, the diameter, and material of metal wire. Finally, a simple plasma ignition mechanism based on multifactors was proposed.

An electrical wire explosion is a complicated process consisting of several physical phenomena such as acoustic, optical, mechanical, electromagnetic, and thermal phenomena. The shock wave from such an explosion not only has a wide range of practical applications but it also plays an important role in analyzing the process of the explosion itself. In this paper, we propose an empirical approach to estimate the pressure and energy of the shock wave in an underwater electrical wire explosion. First, the discharge process is divided into several typical phases, and the deposited electrical energy, power, and time interval between adjacent phases are calculated. Then, the shock wave peak pressure is measured and the total mechanical energy is calculated, respectively. Finally, a multiparameter fitting method is adopted to deduce an empirical formula for peak pressure and shock wave energy, and the formula was the exponential function of the deposited electrical energy, power, and the discharge time interval. In this way, the shock wave pressure and energy are quickly and reliably estimated for given discharge parameters. As for 155 shots of the discharge experiment, the average relative error and the standard deviation of peak pressure are 8.45% and 5.47%, respectively, and those of the shock wave energy of are 12.2% and 11%, respectively. This empirical approach would be very useful in pulsed power device design and in the parameters involved in electrical wire matching.

The behavior of explosive emission cathode plasma was a fundamental physical problem in the study of high current electron beam diode. A diagnosis system was designed for getting the time-resolved and spectrum-resolved emission spectra of cathode plasma on a 1MV diode with dozens of kilo amperes in this paper. A full spectrum of direct reading spectroscopic diagnostic system which includes a high band pass spectrograph with 200–1000nm detection wavelength and an ultra high-speed intensified imaging with 2ns gate time was used in the experiment. The characteristics of emission spectra in different stages during the process of cathode plasma of several cathode materials were obtained. These results are helpful for improving the uniformity of cathode plasma emission in high current diode by choosing suitable surface treatment method of cathode.

The discharge channel development of microsecond electrical exploding tungsten in air was investigated. A microsecond pulsed current source was used to trigger the electrical explosion of tungsten wires with a length of 40 cm and a diameter of 0.3 mm. Charged with a 26 kV voltage, a 6 μF capacitor possessed a stored energy of 2028 J, which was not enough to vaporize the tungsten wire. We proposed two parameters, the total cross-sectional area and the granular border area, to quantitatively describe the discharge channel development. We also adopted an image processing method to study the entire discharge channel development throughout the wire explosion. Evident results suggested that the trend of the electrical explosion was layer by layer from the surface to the core, and the outward expanding speed of the channel was gradually decreasing. The results also demonstrated clear distinction between the discharge channel developments at upper and lower electrodes. During the electrical explosion, the granular border area increased in an approximate exponential way, while the total cross-sectional area increased linearly until 1.43 ms and then decreased, which was caused by hollow regions formed in the discharge channel.