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A systems analysis of the Clover flash cartridge revealed that, of all components present, the lead azide and lead styphnate exhibit the lowest ignition temperatures on furnace heating of test cartridges. Skin temperature during the launching of a Clover cartridge assembly was found to be approximately 120 deg C, far below the ignition temperature of any of the cartridge components. Additional assemblies were preheated to temperatures of 120 and 140 deg C, and series fired. Cartridge skin temperatures of 200 and 270 deg C, respectively, were obtained. All cartridges fired in sequence with no malfunctions. It was thus established that none of the components are prematurely ignited by heat generated during launching. X-ray examination showed no discontinuities in component packing, and 40 ft free fall tests did not cause detonation of cartridges containing FP 790 only. A possible explanation of the premature detonations obtained during series firings is given based upon omission of the black powder/barium chromate expelling charge.

Effects of an oxidant containing added impurties such as Ag(+), Cu(++), and I(-) ions upon the luminosity of flash systems were tested in the following blends: (1) FP600 (60/40 KclO4/Al photoflash composition for sea level application (2) FP790 (30/20/50) Ca/Al/KclO4) photoflash composition for high altitude applications (3) FP856 (31/20/49 Al/CaF/KclO4) high altitude flash compostion. All tests were performed at sea level or at 20.9 mm Hg, simulating 80,000 feet altitude, and a/ the temperature prevailing at the Pyrotechnic Laboratory High Altitude Tank. The system 40/60 Al/KclO4 doped with Ag(+), Cu(++), or I(-) inns exhibited no increase in luminous efficiency over a non-doped control at ambient conditions. At 80,000 feet, increased efficiencies were achieved with doped systems, but the results could not be verified in a second series of tests. Within the systems 30/20/50 Ca/Al/KclO4 and 31/20/49 Al/CaF/ KclO4, the compositions containing KclO4 doped with Ag(+) ions showed the greatest increases in luminous efficiencies, ranging up to 27.0% and 29.4% respectively at 80,000 ft. However, neither system gave verifiable results on retest. The above systems doped with Cu(++) and I(-) ions gave results that were either not verifiable or else exhibited lower efficiency values.

Photoflash sysems containing hafnium and potassium perchlorate in stoichiometric (72/28), fuel rich (77/23, 82/18), and calculated maximum efficiency (87/13) proportions generally exhibit greater luminous efficiency on a volume basis (candleseconds per cubic centimeter) then the conventional 60/40 potassium perchlorate/aluminum and Type 3, Class A photoflash formulations under either ambient conditions or reduced pressure conditions simulating an 80,000-foot altitude. With increased hafnium content, greater integral light and volumetric efficiency values are obtained under either ambient or high altitude conditions. Under reduced pressure conditions, the stoichiometric hafnium/potassium perchlorate system and a ternary blend of hafnium/potassium perchlorate/barium nitrate (72/14/14) gave superior peak light intensity values when compared with the above conventional formulations as well as the optimum high altitude flash system of 80/20 calcium/potassium perchlorate. (Author)