Predetonation conductivity of a TATB-based explosive

Gorshkov, M. M.; Grebyonkin, K. F.; Zaikin, V. T.; Slobodenyukov, V. M.; Tkachev, O. V.

doi:10.1134/1.1792295

Cited by 2 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This assumption was verified by measurements of the conductivity of TATB subjected to a shock wave [7]. It was found that when a shock wave with a pressure at the front of about 15-18 GPa enters a TATB based explosive sample, the electrical conductivity of the sample begins to increase and in ≈0.2 µsec after the beginning of the shock effect, it reaches values of about 1 (Ω· m) −1 .…”

mentioning

confidence: 88%

“…where ε a is the activation energy of conduction electrons, R is the universal gas constant, T is the temperature of the HE, and B is an empirical factor that is chosen so as to describe measured conductivities of unreacted shock-compressed TATB [7]. Here it is assumed that under combustion-wave conditions, the conduction-electron concentration is lower than the electron concentration in the valence band and recombination processes can be ignored.…”

mentioning

confidence: 99%

“…Here it is assumed that under combustion-wave conditions, the conduction-electron concentration is lower than the electron concentration in the valence band and recombination processes can be ignored. These assumptions are valid in the range of not too high pressures (approximately up to 20 GPa) since at such pressures, the experimental conductivity of shock-compressed HEs is lower than the conductivity of metals and increases up to the time the rarefaction wave arrives at the sample [7]. The velocity of combustion-wave propagation from microcenters was calculated as follows.…”

mentioning

confidence: 99%

“…Using the experimental results of [7], we estimate the growth kinetics of conductivity for shockcompressed crystalline TATB:…”

mentioning

confidence: 99%

“…The dependence of the temperature of shock-compressed TATB on the shock front pressure was evaluated from the relation T 1 ≈ 180 + 32p, which was obtained in [11] for an initial HE density equal to 1.91 g/cm 3 . The value of the parameter B = 2 · 10 19 (Ω · m · sec) −1 is chosen so as to describe the measured conductivity [7]. The calculated curve of the combustion-wave velocity D versus shock front pressure is given in Fig.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Electronic Thermal Conductivity during Combustion-Wave Propagation from Hot Spots in Detonating TATB

Grebenkin

Zherebtsov

Taranik

2005

Combust Explos Shock Waves

View full text Add to dashboard Cite

A model for the electronic thermal conductivity of shock-compressed TATB is developed using experimental data on the growth kinetics of its electrical conductivity. It is shown that electronic thermal conduction can be the main mechanism of energy transfer from hot spots in detonating explosives.It is well known that during shock-induced detonations of heterogeneous condensed explosives (HEs), chemical reactions start at so-called hot spots -combustion microcenters which arise from a local temperature rise during shock-wave propagation through heterogeneities in the HE. The volume fraction of the microcenters is small; therefore, most of the HE reacts during combustion-wave propagation from the microcenters and the wave velocity determines the macrokinetics of HE decomposition and energy release (see, for example, [1]).At the macrolevel, the time of chemical-energy release in a detonating heterogeneous HE can be estimated as ∆τ ≈ δ/D, where D is the velocity of combustion-wave propagation from hot spots, δ is the average distance between the hot spots (on the order of the HE microcrystal size). For the characteristic values δ ≈ 10 µm and ∆τ ≈ 0.1-1 µsec, the velocity of combustion-wave propagation from the hot spots is estimated as D ≈ 10-100 m/sec. However, in shock-compressed and heated triaminotrinitrobenzene (TATB), the calculated combustion-wave velocity turned out to be smaller -D ≈ 0.1-1 m/sec [2], indicating the need for a more detailed analysis of the physical processes determining the velocity of combustionwave propagation in shock-compressed HEs.In this connection, it should be noted that the parameters of the calculation model of [2] were chosen so as to describe the measured ignition times of HEs at rather low temperatures at the boundary (up to 700 K) and low pressures (up to 1.5 GPa). The adequacy of this model for the range of much higher pressures and temperatures (10-20 GPa and 2000-3000 K), characteristic of the shock initiation of TATB, is questionable because the chemical-reaction kinetics is known to depend greatly on temperature and pressure.Another possible source of errors in calculations of the combustion of compressed-shock HEs is the great uncertainty in modeling heat transfer from hot spots to the crystalline HE. Experimental data on the thermal conductivity of shock-compressed HEs are not available. Moreover, the thermal conductivity mechanism in this case is not understood. The model of [2] considers only the lattice (phonon) thermal conductivity of HEs. However, phonon thermal conduction is a rather slow process characterized by a relaxation time of about 100 psec (see, for example, [3]). Thus, it is possible that the phonon mechanism of energy transfer from hot spots is ineffective at times of the picosecond scale characteristic of the reaction of HEs in combustion waves [4].The present paper gives calculation results for combustion-wave propagation from hot spots obtained under the assumption [4-6] that energy transfer from hot spots occurs by electronic thermal conduction.

show abstract

mentioning

confidence: 88%

mentioning

confidence: 99%

mentioning

confidence: 99%

“…Using the experimental results of [7], we estimate the growth kinetics of conductivity for shockcompressed crystalline TATB:…”

mentioning

confidence: 99%

mentioning

confidence: 99%