Diameter Curves for Some Commercial Explosives

As was already mentioned, considerable work on relatinnship between charge densities, diameters and detonation velocities was done by Russian scientists. Besides investigating critical (kriticheskii in Rus) densities (p and diameters (dc), they also determined values which. they named limiting (predel nyi, in Rus) density ( ) and diameter (d ). The names of Rus scientists who worked on these subjects until about I960 are Belyaev, Khariton, Bobolev, Petrovskii, Shekhter, etc, and of Polish scientist Urbaifski are listed in Ref 8, pp 261-67 283-95 and Ref 9, pp 196-210, 

Accdg to our translation from the Russian, the critical density (pc) may be defined as the lowest value of loading density, p, at which a detonation wave will propagate thru full length of expl column at steady rate. Smallest further decrease in p will cause failure of detonation. The lowest deton velocity at this point, as registered by high-speed photography, may be considered as critical velocity and the density as critical pc (Ref 8, pp 292-93) 

The limiting density, P, may be defined as the lowest p at which. deton velocity will reach its maximum value, called limiting velocity, De. For HE s like TNT, PETN, RDX, 

Fig 86 of Ref 8, p 290 (shown here as Fig 6) gives relation between log D and log p for TNT (Trotil. in Rus) and RDX (Gheksoghen in Rus), phlegmatized with 5% paraffin. The work was done by Shekhter. D was detd by rotating drum camera. and compared with values calcd from the formula  

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Figure 4 Velocity-diameter curves for some commercial explosives (1. 60 per cent ammonia gelatin 2. 40 per cent ammonia gelatin 3. 60 per cent AN-SN dynamite 4. per cent AN-SN dynamite 5. fuel sensitized coarse-fine AN explosive (pi — 1.3) 6. fine grained AN permissible (pi 0.8, NG 7 per cent) 7. intermediate grained AN permissible (pi = 0.8, NG 7 per cent) 8. coarse grained AN permissible (Pl - 0.8, NG 7 per cent) 9. fine grained AN permissible (pi 0.6)...

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