Projected Response of Typical Detonators to Electrostatic Discharge (ESD) Environments

The purpose of this discussion is to indicate the threshold values for low-order detonator response by using first principles applied to pin-to-pin configurations and associated limits in pin-to-case scenarios. In addition an attempt to define the electrical environment by first principles is shown to be inadequate and indicates the need to define the electrical insult by reasonable standards. A comparison of two accepted electrical models and a combination of the extreme reported levels from both standards are used to establish an extreme set of parameters for a safety assessment. A simplification of the critical electrical insult parameters is then shown and demonstrated to provide the initial screening protocol with easily defined electrical dimensions of action integral. Action integral and the conductive material properties are the basic parameters needed to define the solid, liquid, and gas phases of the material used for detonator bridge wires. The resulting material phases are directly related to detonator response thresholds. The discussion concludes by showing the ability of ESD insults to arc from pin-to-case, the limited knowledge of the associated arc initiation process, and the modeling need for a reasonable arc resistance in pin-to-case scenarios.