Document Type : Original Research Article
Technical research center, Cairo, Egypt
Pyrotechnic decoy flares are the most widely used passive countermeasures for heat-seeking missiles. The development of (photoconductive) InSb-detectors with cut-off wavelength>6 μm has allowed two-color detectors working in both short (α) (1.8-2.5 μm) and mid-wave (β) (3.5-4.8 μm) bands. Thus, it is possible to determine the sensitivity ratio and to discriminate against fake targets. An attempt was made to change the spectral distribution of MTV (Magnesium-Teflon-Viton) decoy flare compositions by adding another composition to modify spectral emission based on aluminum, hexamine, potassium nitrate and ammonium perchlorate. Aluminum emission at 1.5 µm due to Al2O3. Hexamine used as flame expanders due and to provide cooling of the flame to transform radiation from a spot location to a burning zone. In this study, theoretical and experimental comparisons were made between various spectrally adapted flame compositions based on epoxy as a binder and the MTE flare which represented by sample (4). The first composition was Mg/Teflon/Epoxy (MTE) with percentage (60-80)% and the second adapted compositions with percentage (20-40)%. The temperature of the flame and the time of burning were measured using an inframetric radiometer. The radiant emission was determined using a computer program. The results show that sample (1) which contains 20% of the adapted compositions produces high flame temperature (1300 °C) and the highest radiant emittance 6.6 W/cm2/µm.