Article published Pyrotechnics
Optical detonator for enhanced safety
Thanks to its fibre optics, the CEA detonator design presents advantages in terms of security and controlling operating time.
Pyrotechnic devices are used in many civil and military fields. During priming, the detonator receives incident energy that is converted into thermal or mechanic energy (shock wave), which in turn causes the priming explosives to react.
Thus, to guarantee maximum security, it is essential to avoid any ill-timed priming in the pyrotechnics chain. To this end, the use of low-sensitivity priming explosives can prove to be highly effective, on condition that the detonator is powerful enough to initiate them. Researchers from the Military Applications Division (DAM) have developed a design for a so-called "high-energy" optical detonator that is extremely powerful. "The incident energy is not transmitted using an electrical distribution cable, but using fibre optics," explains Franck Delmaire-Sizes, who designed a complete optical-pyrotechnic chain demonstrator.
In addition to an increase in generated pressure, this device controls the operation time, meaning that any synchronisation differences between the various detonators are limited. This property is beneficial for applications in the field of self-propelled systems (missile, launchers, etc.) where complex priming architectures mean that multiple initiation points are required. Furthermore, the energy loss in the fibre optic is lower than in an electrical cable, making it possible to overcome the distance limits between the source and the detonator. The very design of these detonators lends them a greater resistance to electromagnetic and electric damage. To conclude, this device makes it possible to reduce the device's weight.
