Ultraviolet, visible and infrared ignition of pyrotechnic compositions

The ignition of several common pyrotechnic compositions has been evaluated using ultraviolet (UV), visible and infrared (IR) radiation. A broadband Xenon lamp and a high power laser diode were the radiation sources used. At irradiance levels of 4.9 W/cm(2) none of the compositions were ignited using UV radiation. Most of the compositions were ignited with IR radiation but Mg/NaNO3 and SR 112 could not be ignited at irradiance levels of up to 300 W/cm(2). SR112, B/Fe2O3 and gunpowder showed reactions to visible radiation at power densities as low as 8.1 W/cm(2). The difference in the response of the compositions was not directly related to the absorption characteristics of the compositions; it was dependant on many physical, chemical and optical characteristics of the pyrotechnic powder. Increasing the irradiance reduces the time to ignition for most compositions.