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A Semiconductor Bridge (SCB) explosive initiator has many advantages such as shorter action time, better ignition consistency and higher reliability. The development of a SCB has traditionally been guided by an experimental approach. Experiments conducted worldwide show that the melting and vaporization of a SCB when heated by an electrical current is a very complex physical process. In this process, the bridge goes through multi-phase changes, i.e., in order solid, liquid, gaseous and plasma-state. This paper discusses the numerical simulation of the SCB working process when driven with a short low-energy pulse. In an effort to elucidate the behaviors of the SCB working process, the temperature distribution before the SCB melting and SCB discharge are presented. The basic semiconductor equations and heat transfer equation are described to evaluate the temperature distribution in the SCB. The results are obtained from finite-difference implementations. The edge gasification effect of SCB is proved by the curve of temperature distribution, and the double temperature characteristic of SCB is shown. Finally, a SCB discharge model is established. The result shows that the bigger the external voltage, the longer is the discharge time. [ABSTRACT FROM PUBLISHER]

The semiconductor bridge (SCB) is a heavily n-doped semiconductor. The SCB device has advantages for reducing voltage and energy requirements compared with a conventional device. It also has very excellent safety. When driven with a short low-energy pulse, the SCB creates hot plasma to ignite energetic materials. The hot plasma permeates the energetic materials and deposits its latent heat of fusion to the grains, thereby heating the granular surfaces to energy states required for self-sustained reaction. The behavior of the SCB can be facilitated through the simulation of the electrical components. The resistance of the SCB is a key parameter during the process of producing the plasma. The dynamic resistance of a heavily doped semiconductor resistor was evaluated by observing the electrical mobility and conductivity of the resistor as a function of temperature covering the range from room temperature to the plasma temperature. In an effort to elucidate the dynamic resistance of the SCB, current was forced to flow through the bridge with an initial resistance of 1 \Omega. The energy stored in a 25- \mu\F capacitor was used to activate the plasma. Two peaks in the voltage–time curve were typically observed. Time histories of the resistance and voltage show the special features of the resistor. It appears that the resistance increases initially before the intrinsic temperature and then decreases due to negative resistance behavior, and then, the resistor is melted and vaporized to generate plasma. [ABSTRACT FROM PUBLISHER]