Structure Measurements in Condensed Explosives

Detonation Wave Structure Measurements in Condensed Explosives. Measurements of the de tonation- wave structure at the axis of long cylindrical charges of NMe and TNT were conducted by Craig (Ref 95a)- He de-teimined initial free- surface velocities of plates of various thicknesses driven by the explosives. The plates were either of Dural (an aluminum alloy contg 4% Cu, 0.5% 

0% Mn and small amounts of Fe Si), or of Sierracin (a thermosetting plastic which is not attacked by NMe as are most plastics). The plate velocities are accdg to Duff Houston (Ref 38a), related to the pressure in the explosive at a distance back in the explosive approximately proportional to the plate thickness. The free surface velocities were measured using a smear camera technique, described by Davis Craig (Ref 67a). Here the apparent position of the image of an object reflected in the free surface was recorded as a function of time. The measurements showed that a real detonation wave consists at the charge axis of three zones  

The reaction zone of NMe is too thin to be observed by the plate—velocity technique, but its presence can be inferred from other experiments. Its length was estimated to be ca 1000 A from an extrapolation of the unreacted equation of state discussed by Ilyukhin et al (Ref 64b) and the adiabatic thermal explosion theory dis cussed by Zinn Mader (Ref 64a). The pressure, p. . at the end of reaction zone which corres-ponds to the head of decay zone), was estimated to be I4lkbar, when free-surface velocity was determined using Dural plates and 135kbar when using Sierracin plate 

The reaction zone of TNT could be resolved with the plate technique. The pressure at the end of the reaction zone, which is called by Craigft-J pressure was found to be not constant (as in the case of NMe), but it changed with the charge size, its diameter, length, boostering, or confinement. For example, the pressure for pressed TNT chge of density  

63 g/cc at 23°and diam 42 mm was 200kbar after the run of 8 diameters corresponding pressure for larger chge (77 mm diam) was 

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See also Detonation Wave Structure Measurements in Condensed Explosives Detonation Wave Study by a Missile Technique and Detonation Wave Study by Spectrophotometric-Analysis)... 

CA 49, 10625 (1955) (Structure of detonation wave front of gases was studied by method of shock tube) (See its abstract under Detonation Wave Structure) 38a) R.E. Duff E. Houston, 2nd ONRSympDeton (1955), p 225 (See under Detonation Wave Structure Measurements in Condensed Explosives) 39) S. Minshall, JApplPhys 26, 463- 69 (1955) (Properties of elastic and plastic waves determined by pin contactors and crystals) 40) C.G. Dunkle, "Introduction to Theory of Detonation of Explosives, Syllabus of 21 Nov 1955 and Lecture Delivered at Picatinny Arsenal on 13 Dec, 1955 (Structure of the deton wave)... 

Phys. 31, 323 (1960) (See under Detonation Wave Structure Measurement in condensed Explosives) 64b) V.S. Ilyukhin, Dokl-AkadN 131, 793 (I960) pee under Detonation Wave Structure Measurements)... 

See under Detonation Wave Structure Measurements in Condensed Explosives)... 

Measurement of the Detonation-Front Structure in Condensed-Phase Explosives , Ibid, 863-67 11) W.E. Gordon, "Detonation Limits in Condensed Explosives , 4thONRSympDeton(1965), 179-97 12) M.C. Chick, "The Effect of... 

It is deecribed by us as Detonation, NDZ (Neumann-Doring-Zel dovich) Theory. Spike theory was also described by Dunkle (Refs 1 3). Boyle et al (Ref 5) in the paper entitled "Measurements of the Detonation-Front Structure in Condensed Explosives lists spike pressure for Comb B as equal to 388 kbars... 

Lastly, we discuss some preliminary results of a study of the energy distribution around defects in a monatomic lattice under shock compression. Many investigators have studied the initiation of chemical reaction in condensed explosives by the mechanism of "hotspots," both experimentally [40] and theoretically [41]. Because of experimental difficulties, few quantitative measurements on "hotspots" have been reported. From the theoretical side, various mechanisms have been postulated, but not completely verified. MD investigations [42] thus far have focused on energy distributions and structural configurations in non-reactive systems in the condensed phase, some containing defects. In our first attempt... 

B.G. Craig, "Measurements of the Detonation-Front Structure in Condensed-Phase Explosions , lOthSympCombstn (1965), pp 863-67 6) W.C. Davis et al,... 

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