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 XII International Symposium on Explosive Production of New Materials: Science, Technology, Business, and Innovations (EPNM-2014), May 25-30, 2014, Krakow, Poland

Goals 1.Measurements of the detonation front temperature of emulsion explosives (EMX) 2.Why? –The temperature is the most sensitive detonation parameter to the EOS –Development & calibration of EOS of 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). 3.Better knowledge of the EMX’s properties is needed.

3 EMX’s Temperature. Review Numerical calculations: КYoshida M., et al.; Tanaka K. : 1985, 8th IDS – Kihara-Hikita EOS, К КOdinzov et al.; Alymova et al.: 1994, Chemical Reports, BKW EOS; Combustion, Explosion, and Shock Waves, thermodynamic code, К 1700 КTanaka, 2005, APS-2005, KHT EOS, 1700 К single article Lefrancois A., et al. / 12th Symp. (Intern.) on Detonation, 2002.Nitram explosive (based on AN emulsion) T b = 4179 K (?) Experiment: single article Lefrancois A., et al. / 12th Symp. (Intern.) on Detonation, Nitram explosive (based on AN emulsion) – T b = 4179 K (?)

4 EMX composition OxidizerOxidizer – water solution of mixture AN & SN nitrates, 94 wt. % FuelFuel – liquid hydrocarbon + emulsifier, 6 wt. % SensitizerSensitizer – glass microballoons 60 μm in size, from 1 to 50 wt. % above an emulsion weight EMX parameters detonation pressure 0.7 – 11 GPaEMX 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 fiberoptical pyrometerSelf-made four channel fiber optical pyrometer with quartz fiber 0.4/0.8 mm in diameter and up to 15 m in length Planck’ distributionBlack bodyBasis – Planck’ distribution and Black body approximation Brightness temperature 630(20)Brightness temperature at 630(20) & 660(120) nm FMPFMP – spectral range 300 ÷ 750 nm CalibrationCalibration before each shot, lamp 1100 – 2350 K and interpolation to higher temperature Accuracy  KAccuracy  K Testing – PMMA, epoxy resin, PTFE at KTesting – PMMA, epoxy resin, PTFE at K Details in Vestnik NSU, 2011, 6(1), (in Russian)Details in Vestnik NSU, 2011, 6(1), (in Russian)

6 Experimental setup – window technique 3 – emulsion explosive Ø55x250 mm (at max density Ø105x400 mm), pressure gauge, 7 – Plexiglas window 15 mm in thick, 8 Ø6 mm,9 – optical fiber with 0.4 mm quartz core (to pyrometer) or Visar probe 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 Luminosity signal interpretation Purpose – the choose a point to measure the Temperature of Detonation Products according the classic ZND model 0.7 GPa Registered profile (1) = hot spot (3) + detonation temperature (2) Temperature (1), pressure (2), particle velocity (3) 1880 K Main idea Correlation of three profiles

8 Luminosity (1) & Temperature (2) t 1 – detonation reaches the EMX/window interface P D = 4.4 GPa t R = 0.65 μs 2140 K P D = 10.7 GPa t R = 1.3 μs 1940 K mcs

9 Brightness temperature of detonation front vs detonation pressure (experiment) Correction model EMX – low-temperature explosive ~ 2000 K Hot spots Detonation front T CJ, calculation P d, GPa

10 Comparison with calculations EMX based on AN/SN emulsion calculations experiment P d, GPa

11 Lefrancois A., et al. // 12th Symp. (Intern.) on Detonation, 2002, Temperature and pressure measurements comparison of the aluminized emulsion explosives detonation front and products expansion Lefrancois A., et al. // 12th Symp. (Intern.) on Detonation, 2002, Temperature and pressure measurements comparison of the aluminized emulsion explosives detonation front and products expansion Nitram “a” explosive (based on AN emulsion) without aluminum → 4179 К French producer calculation is 2170 ÷ 2500 К about two times lower ! ÷ according our methodology T = 2200 ÷ 2300 K at 0.7-0,8 μs behind detonation front

Conclusions The alternative view on the structure of the spectral radiancean emulsion explosiveThe 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 by the comparison of pressure, particle velocity and temperature profiles behind the detonation frontThe 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 in qualitative and quantitative accordanceOur experimental results are in qualitative and quantitative accordance with independent calculations from 1 to 11 GPa the detonation temperature of EMX is1840 ÷ 2260 K non-monotonous behavior on pressureIn the range of detonation pressures from 1 to 11 GPa the detonation temperature of EMX is 1840 ÷ 2260 K and has non-monotonous behavior on pressure. Temperature maximum is about at 6 GPaTemperature maximum is about at 6 GPa

Acknowledgments The work was supported by 1.the Russian Foundation for Basic Research (project а), 2.the Presidium of the Russian Academy of Science (project 2.9), 3.the President of the Russian Federation for State Support of Leading Scientific Schools (grant NSh ). THANKS YOU FOR ATTENTION

14 Appendix

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

16 Planck’ distribution Two wave lengths 630 (20) nm x 45 times 660 (120) nm x 38 times T T 660 ≈ K Wide dynamic range of pyrometer is needed to register and “hot spots”, and detonation temperatures

17 Shocked mono-layer luminosity model of “hot spots” layer 20 GPa 9 GPa  t = 0.2 – 0.6  s T hs ~ 1.5-2T matrix 5-10 mm 2.4 – 5.1 km/s Explosively driven duralumin plate Optical fiber Ø0.2 mm, ~ 10 m GMBs ~ 60 μm to FMT filter Matrix epoxy, water ~ 18º mask Ø6 mm