On Possibility of Detonation Products Temperature Measurements of Emulsion Explosives

1. XII International Symposium on Explosive Production of New Materials: Science, Technology, Business, and Innovations(EPNM-2014), May 25-30, 2014, Krakow, Poland On Possibility of Detonation Products Temperature Measurements of Emulsion Explosives Victor V. Sil’vestrov, S.A. Bordzilovskii, S.M. Karakhanov, and A.V. Plastinin Lavrentyev Institute of Hydrodynamics Novosibirsk, Russia

2. Goals • Measurements of the detonation front temperature of emulsion explosives (EMX) • Why? • The temperature is the most sensitive detonation parameter to the EOS • Development &calibration ofEOSof detonation products for EMX, decomposition kinetics. • Application of EMX to the delicate explosive welding is the reality today (thin foils, low-melting-point metals, tube plates and others). • Better knowledge of the EMX’s properties is needed.

3. EMX’s Temperature. Review Numerical calculations: • Yoshida M., et al.; TanakaK.: 1985, 8th IDS – Kihara-HikitaEOS, 1900-2100 К • Odinzovet al.; Alymova et al.: 1994, Chemical Reports, BKW EOS; Combustion, Explosion, and Shock Waves, thermodynamic code, 1000-1700 К • Tanaka, 2005, APS-2005, KHT EOS, 1700 К Experiment:single article Lefrancois A., et al. / 12th Symp. (Intern.) on Detonation, 2002.Nitram explosive (based on AN emulsion) – Tb = 4179 K (?)

4. EMX composition • Oxidizer – water solution of mixture AN & SN nitrates, 94 wt. % • Fuel – liquid hydrocarbon + emulsifier, 6 wt. % • Sensitizer – glass microballoons 60 μm in size, from 1 to 50 wt. % above an emulsion weight • EMX parameters: density 0.5 – 1.3 g/cc, detonation pressure 0.7 – 11 GPa, VOD 2.1 – 6 km/s, critical diameter 5 – 38 mm

5. Measuring procedure • Self-made four channel fiberoptical pyrometer with quartz fiber 0.4/0.8 mm in diameter and up to 15 m in length • Basis – Planck’ distribution and Black body approximation • Brightness temperatureat630(20) & 660(120) nm • FMP – spectral range 300 ÷ 750 nm • Calibration before each shot, lamp 1100 – 2350 K and interpolation to higher temperature • Accuracy  50-150 K • Testing – PMMA, epoxy resin, PTFE at 1500-3000 K • Details in Vestnik NSU, 2011, 6(1), 116-122 (in Russian)

6. Experimental setup – window technique 1 – HV detonator, 2 – 5% EMX primer, 3 – emulsion explosive Ø55x250 mm (at max density Ø105x400 mm), 4 – polypropylene tube with 5 mm wall, 5 – contact pin, 6 – PVF2 or manganin pressure gauge, 7 – Plexiglas window 15 mm in thick, 8 – mask Ø6 mm,9 – optical fiber with 0.4 mm quartz core (to pyrometer) or Visar probe

7. Main idea Correlationof three profiles 0.7 GPa 1880 K Temperature (1), pressure (2), particle velocity (3) Registered profile (1) = hot spot (3) + detonation temperature (2) Luminosity signal interpretation Purpose – the choose a point to measure the Temperature of Detonation Products according the classic ZND model

8. 2140 K 1940 K mcs PD = 4.4 GPa tR = 0.65 μs PD = 10.7 GPa tR = 1.3 μs t1 – detonation reaches the EMX/window interface Luminosity (1) & Temperature (2)

9. Hot spots Detonation front TCJ, calculation Correction model EMX – low-temperatureexplosive ~ 2000 K Pd, GPa Brightness temperature of detonation front vs detonation pressure(experiment)

10. experiment calculations Pd, GPa Comparison with calculationsEMXbased on AN/SNemulsion

11. according our methodology T =2200 ÷2300 Kat 0.7-0,8 μs behind detonation front Lefrancois A.,et al. //12th Symp. (Intern.) on Detonation, 2002,432-439Temperature and pressure measurements comparison of the aluminized emulsion explosives detonation front and products expansion Nitram “a”explosive (based on AN emulsion) withoutaluminum→ 4179 К French producer calculation is 2170÷2500 К about two times lower !

12. Conclusions • The alternative view on the structure of the spectral radiance signal recorded at detonation of an emulsion explosive with embedded glass microballoons • The location of the point to estimate the detonation temperature is defined by the comparison of pressure, particle velocity and temperature profiles behind the detonation front • Our experimental results are in qualitative and quantitative accordance with independentcalculations • In the range of detonation pressures from 1 to 11 GPathe detonation temperature of EMX is1840 ÷ 2260 K and has non-monotonous behavior on pressure. • Temperature maximum is about at 6 GPa

13. Acknowledgments • The work was supported by • the Russian Foundation for Basic Research (project 12-08-00092-а), • the Presidium of the Russian Academy of Science (project 2.9), • the President of the Russian Federation for State Support of Leading Scientific Schools (grant NSh-2695.2014.1). • THANKS YOU FOR ATTENTION

14. Appendix

15. Detonation temperature measurement of heterogeneous explosives / Problems Optical method based on the radiance of shocked/reacted matter  hi-time resolution Transparent window technique / low shock impedancematerial is needed for EMX’s Interpretation: short reaction time  luminosity maximum to temperature estimation / longer reaction time (?) Mismatch of acoustic impedances of window material and explosive investigated  complexity of result’s analysis / EOS of detonation products, black/grey/non-equilibrium body model, effect of physical inclusions High “hot spots” temperature / Low “matrix” temperature very large dynamic range of technique used, high sensitivity

16. Planck’ distribution Two wave lengths 630 (20) nmx 45 times 660 (120) nmx 38 times Wide dynamic range of pyrometer is needed to register and “hot spots”, and detonation temperatures T630 - T660≈ 30-50 K

17. Explosively driven duralumin plate 5-10 mm 2.4 – 5.1 km/s ~ 18º Matrix epoxy, water GMBs ~ 60 μm Optical fiber Ø0.2 mm, ~ 10 m mask Ø6 mm filter to FMT Shocked mono-layer luminositymodel of “hot spots” layer 20 GPa 9 GPa Dt = 0.2 – 0.6 ms Ths ~ 1.5-2Tmatrix