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Ignition and growth modeling of detonation reaction zone experiments on single crystals of PETN and HMX

“…The ~100 ns single crystal PETN reaction time is supported by electrical conductivity measurements of solid carbon formation lasting 40 -70 ns [13,14]. The measured reaction zone times for pressed PETN are 5 to 10 ns [5,9,15]. These single crystal HMX and PETN I&G parameters are also used to estimate their unconfined failure diameters.…”

Thermally Stable and Low‐Sensitive Aluminized Explosives with Improved Detonation Performance

“…Therefore, the time history of -du p /dt is applied to determine the CJ point on the particle velocity profile. With allowance for the experimental error, the dependence of -du p /dt on t in semilogarithmic coordinates is represented as two straight lines, and the second line has practically zero slopes (du p /dt � const) [27]. The point of intersection of these lines, which corresponds to the Jouguet plane, determines the reaction time t CJ (the time of passage of the HE element from the front to the Jouguet plane) The time history of -du p /dt and two linear fits to the -du p /dt profile are presented in Figure 11.…”

On the mechanism of carbon nanostructures formation at reaction of organic compounds at high pressure and temperature

“…For the densities lower than the critical one, the speed of decomposition is maximal in the shock front and then monotonically decreases. 24 Following the argument of chemoionization, conductivity should be the higher the faster the initial substance decomposes, that is the maximum of conductivity σ max should be close to the detonation front. According to our data for HEs with well defined conductivity peak, σ max is reached at about the half of duration of the zone of increased conductivity, 4,19,22,[25][26][27] i.e., far from the front which contradicts to the relation of the conductivity σ and the intensity of reactions.…”

“…In the detonation wave, pressure and density reach maximum values near the front and then decrease monotonically. 17,24,29,30 When pressure and density decrease, the intensity of recombination decreases, 31 the mobility of electrons increases, and the concentration of reacting component decreases. From this, one would expect that conductivity would at least not fall at the decrease of pressure and density which is not observed.…”