Explosion in a Charge of TNT

If the relation lef/lr (where lt is the width of the reaction Zone) of an initiating expl is small, the process starting with a low detonation velocity eventually developed into normal detonation with velocity D This is represented by curve 2 of Fig 2 

If deton vel of an initiator (of optional length and of the same diam as the main charge), were higher than deton vel of the main chge, the deton proceeded for a length of a few cms in the main chge at vel higher than ks normal value, D,jet. This is shown by curve 3 of Fig 2 Curve 4 of Fig 2 shows the case of deton which fades after its vel reaches the critical value Dcr 

Following are three curves (Figs 3, 4 5) [taken from the book of Baum et al (Ref 1, pp 279-80)] which show dependence of lcr from various factors, as detnd by the method illustrated in Fig 1 

In Fig 3 is shown the dependence of critical length (lcr) of detonators (diam d=24.5 mm charged with Tetryl of p0=1.6) from the length of column. As can be seen, 50 mm is the optimal length 

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