This invention relates to a new igniter of a semiconductor nature which is especially useful in conjunction with insensitive high explosives and pyrotechnics.
Various means for detonation, deflagration or other activation of explosives, including the mentioned high explosives, are known. For example, U.S. Pat. No. 3,018,732 discloses a spark gap device. U.S. Pat. No. 3,019,732 also discloses another type of spark igniter. U.S. Pat. No. 3,211,096 is typical of thermal methods for ignition, e.g., hot wire devices. U.S. Pat. No. 3,978,791 and U.S. Pat. No. 3,292,537 also typify hot wire detonators. Slapper detonators are also known, but these require high voltage, high power, and complex and costly capacitive firing sets along with precision manufacturing and alignment. See, e.g., Sandia Report 78-1491 by A. C. Schwarz.
The disclosure of U.S. Pat. No. 3,366,055 describes a semiconductor device capable of fast, low energy detonation of high explosives. The theory of this patent relates to the use of a strongly crystalline structure having semiconductor properties such that it has a sharp inflection point at which the change from extrinsic to intrinsic conduction occurs, whereby resistivity decreases sharply. At this point, a shock wave is released capable of detonating a high explosive. This turnover point was believed to be controlled by controlling the doping level of the semiconductor and matching it with the desired autoignition temperature for the specific explosive involved. However, applicants have determined that the doping level is not germane to the critical aspects of final performance.
As a result, a new design for a semiconductor-based method of igniting/detonating high explosives is needed.