We have had a key role in research on energetic materials ever since the late Professor Bowden began work in this area during The Second World War. Many former members now hold important positions in laboratories throughout the world. We have, on average, six people researching in this area. High-speed photography has been used extensively. A range of other techniques such as mass and photon spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) have also been employed.
The approach has concentrated on understanding the mechanisms by which various physical processes can create "hot-spots" and cause ignition. The research is invariably on small samples (single crystals, films of liquid etc.). Experimental ingenuity is used to model or photograph particular processes. A series of Royal Society and Nature papers published since the 1940s (see below) are highly regarded by the explosives community.
The research carried out in the group is highly regarded within the explosives community on both a national and international level. With the cost of full scale testing of explosive devices continually rising, the group is extremely important as a leader in highly instrumented precision small scale testing. It is only from these small scale tests that the data required to model large scale devices can be obtained. The research into fast reactions in explosive materials is complemented by research performed using both the high-strain rate and optical techniques available in the group.
 |
Streak photograph showing the deflagration-to-detonation transition in PETN |
Royal Society & Nature Papers
1947 Bowden, F.P., Mulcahy, M.F.R., Vines, R.G. and Yoffe, A. "The detonation of liquid explosives by gentle impact: The effect of minute gas spaces", Proc. R. Soc. Lond. A 188 291-311
1947 Bowden, F.P., Mulcahy, M.F.R., Vines, R.G. and Yoffe, A. "The period of impact, the time of initiation and the rate of growth of the explosion of nitroglycerine", Proc. R. Soc. Lond. A 188 311-329
1947 Bowden, F.P., Mulcahy, M.F.R., Vines, R.G. and Yoffe, A.D. (1947). "Detonation of liquid explosives by impact", Nature 157105
1947 Bowden, F.P., Stone, M.A. and Tudor, G.K. "Hot spots on rubbing surfaces and the detonation of explosives by friction", Proc. R. Soc. Lond. A 188 329-349
1948 Bowden, F.P. and Gurton, O.A. "Birth and growth of the explosion in solids initiated by impact", Nature 161 348
1948 Bowden, F.P. and Gurton, O.A. "Initiation of explosions by grit particles", Nature 162 654
1948 Robertson, A.J. and Yoffe, A.D. "Gases liberated from explosions initiated by impact", Nature 161 806
1948 Yoffe, A.D. "Initiation of explosives by adiabatic compression of their own vapour", Nature 161 349
1948 Yoffe A.D. "The growth of explosion in solids", Proc. R. Soc. Lond. A 246 254-257
1949 Bowden, F.P. and Gurton, O.A. "Birth and growth of explosion in liquids and solids initiated by impact and friction", Proc. R. Soc. Lond. A 198 350-372
1949 Bowden, F.P. and Gurton, O.A. "Initiation of solid explosives by impact and friction: the influence of grit", Proc. R. Soc. Lond. A 198 337-349
1949 Gray, P. and Yoffe, A.D. "Inflammation of explosive vapours and the influence of inert diluents", Nature 164 830
1949 Yoffe, A. "Influence of entrapped gas on initiation of explosion in liquids and solids", Proc. R. Soc. Lond. A 198 373-388
1950 Bowden, F.P. "The initiation of an explosion and its growth to detonation", Proc. R. Soc. Lond. A 204 20-25
1951 Bowden, F.P. and Williams, H.T. "Initiation and propagation of explosion in azides and fulminates", Proc. R. Soc. Lond. A 208 176-188
1951 Yoffe, A.D. "Thermal decomposition and explosion of azides", Proc. R. Soc. Lond. A 208 188-199
1952 Blackwood, J.D. and Bowden, F.P. "The initiation, burning and thermal decomposition of gunpowder", Proc. R. Soc. Lond. A 213 285-306
1953 Bowden, F.P. and Singh, K. "Size effects in the initiation and growth of explosion", Nature 172 378-379
1955 Bowden, F.P. and McLaren, A. "Conditions of explosion of azides: Effect of size on detonation velocity", Nature 175 631
1955 Bowden, F.P. and Singh, K. "Irradiation of explosives with high-speed particles and the influence of crystal size on explosion", Proc. R. Soc. Lond. A 227 22-37
1955 Courtney-Pratt, J.S. and Rogers, G.T. "Conditions of explosion of azides: Initiation of explosion by light and by flying fragments", Nature 175 632
1956 Bowden, F.P. and McAuslan, J.H. "Slow decomposition of explosive crystals", Nature 178 408-410
1956 Evans, B.L. and Yoffe, A.D. "The burning and explosion of single crystals", Proc. R. Soc. Lond. A 238 325-333
1956 Evans, B.L. and Yoffe, A.D. "Structure and stability of inorganic azides", Proc. R. Soc. Lond. A 238 568-574
1957 Yoffe A.D. "Initiation and growth of explosion in solids" Nature 180 73-75
1959 Evans, B.L. and Yoffe, A.D. "Structure and stability of inorganic azides. II: Some physical and optical properties, and the fast decomposition of solid monovalent inorganic azides", Proc. R. Soc. Lond. A 250 346-366
1960 Deb, S.K. and Yoffe, A.D. "Reactivity of azides in the solid state. I: Optical properties and photochemical decomposition of thallous azide", Proc. R. Soc. Lond. A 256 514-527
1960 Deb, S.K. and Yoffe, A.D. "Reactivity of azides in the solid state. II: Physical and optical properties, and photochemical decomposition of mercurous azide and triphenyl methyl azide", Proc. R. Soc. Lond. A 256 528-539
1965 Bowden, F.P. and McOnie, M.P. "Cavities and micro-Munro jets in liquids: their role in explosion", Nature 206 380-383
1966 Bowden, F.P. "The physics of impact and deformation: Single impact. III: The formation of microjets in liquids under the influence of impact or shock", Phil. Trans. R. Soc. Lond. A 260 94-95
1966 Bowden, F.P. and McOnie, M.P. "Formation of cavities and microjets in liquids and their role in initiation and growth of explosion", Proc. R. Soc. Lond. A 298 38-50
1966 Walker, R.F., Gane, N. and Bowden, F.P. "The influence of crystal size and crystallographic orientation on decomposition in the solid state: Sodium and thallous azides", Proc. R. Soc. Lond. A 294 417-436
1967 Iqbal, Z. and Yoffe, A.D. "Electronic structure and stability of the inorganic fulminates", Proc. R. Soc. Lond. A 302 35-49
1968 Bowden F.P. and Chaudhri M.M. "Initiation of explosion in AgN3 and β-PbN6 single crystals by a collapsing bubble", Nature 220 690-694
1968 Bowden, F.P., Fox, P.G. and Soria-Ruiz, J. "Direct observation of thermal decomposition produced by fracture in brittle crystalline solids", Nature 220 778-779
1970 Fox P.G. and Soria-Ruiz J. "Fracture induced thermal decomposition in brittle crystalline solids" Proc. R. Soc. Lond. A 317 79-90
1973 Chaudhri, M.M. "High-speed photography of electrical breakdown and explosion of silver azide crystals", Nature 242 110-111
1973 Coley, G.D. and Field, J.E. "The role of cavities in the initiation and growth of explosion in liquids", Proc. R. Soc. Lond. A 335 67-86
1974 Chaudhri, M.M. and Field, J.E. "The role of rapidly compressed gas pockets in the initiation of condensed explosives", Proc. R. Soc. Lond. A 340 113-128
1974 Heavens, S.N. and Field, J.E. "The ignition of a thin layer of explosive by impact", Proc. R. Soc. Lond. A 338 77-93
1975 Winter, R.W. and Field, J.E. (1975). "The role of localized plastic flow in the impact initiation of explosives", Proc. R. Soc. Lond. A 343 399-413
1976 Chaudhri, M.M. "Stab initiation of explosives", Nature 263 121-122
1979 Tang, T.B. and Chaudhri, M.M. "The thermal decomposition of silver azide", Proc. R. Soc. Lond. A 369 83-104
1979 Tang, T.B. and Chaudhri, M.M. "Dielectric breakdown by electrically-induced decomposition", Nature 282 54-55
1982 Field, J.E., Swallowe, G.M. and Heavens, S.N. "Ignition mechanisms of explosives during mechanical deformation", Proc. R. Soc. Lond. A 382 231-244
1982 Palmer, S.J.P. and Field, J.E. "The deformation and fracture of β-HMX", Proc. R. Soc. Lond. A 383 399-407
1982 Swallowe, G.M. and Field, J.E. "The ignition of a thin layer of explosive by impact: the effect of polymer particles", Proc. R. Soc. Lond. A 379 389-408
1983 Tang, T.B. and Krishna Mohan, V. "Thermal decomposition of solids", Nature 303 729
1987 Johnson, J.N. (1987). "Hot-spot reaction under transient pressure conditions", Proc. R. Soc. Lond. A 413 329-350
1991 Bourne, N.K. and Field, J.E. "Bubble collapse and the initiation of explosion", Proc. R. Soc. Lond. A 435 423-435
1992 Constantinou, C.P., Mukundan, T. and Chaudhri, M.M. "Sensitization of nitrocompounds by amines", Phil. Trans. R. Soc. Lond. A 339 403-417
1992 Field, J.E., Bourne, N.K., Palmer, S.J.P. and Walley, S.M. (1992). "Hot-spot ignition mechanisms for explosives and propellants", Phil. Trans. R. Soc. Lond. A 339 269-283
1992 Walley, S.M., Field, J.E. and Palmer, S.J.P. "Impact sensitivity of propellants", Proc. R. Soc. Lond. A 438 571-583
1993 Dickson, P.M. and Field, J.E. "Initiation and propagation in primary explosives", Proc. R. Soc. Lond. A 441 359-375
1993 Palmer, S.J.P., Field, J.E. and Huntley, J.M. (1993). "Deformation, strengths and strains to failure of polymer bonded explosives", Proc. R. Soc. Lond. A 440 399-419
1995 Luebcke, P.E., Dickson, P.M. and Field, J.E. "An experimental study of the deflagration to detonation transition in granular secondary explosives", Proc. R. Soc. Lond. A 448 439-448
1996 Me-Bar, Y. "On cavitation in thin liquid layers", Proc. R. Soc. Lond. A 452 741-755
1996 Me-Bar, Y. "On the collapse of vapour cavities in a thin liquid layer under high pressure transient", Proc. R. Soc. Lond. A 452 757-768
1999 Bourne, N.K. and Field, J.E. "Shock-induced collapse and luminescence by cavities" Phil. Trans. R. Soc. Lond. A 357 295-311
1999 Bourne, N.K. and Field, J.E. "Explosive ignition by the collapse of cavities" Proc. R. Soc. Lond. A 455 2411-2426
2000 Walley S.M., Balzer J.E., Proud W.G. & Field J.E. "Response of thermites to dynamic high pressure and shear", Proc. R. Soc. Lond. A 456 1483-1503
2002 Rae, P J, Goldrein, H T, Palmer, S J P, Field, J E and Lewis, A L (2002) "Quasi-static studies of the deformation and failure of β-HMX based polymer bonded explosives", Proc. R. Soc. Lond. A458 743-762
2002 Rae P.J., Palmer S.J.P., Goldrein H.T., Field J.E. and Lewis A.L. (2002) "Quasistatic studies of the deformation and failure of PBX 9501" Proc. R. Soc. Lond. A458 2227-2242
2004 Balzer J.E., Siviour C.R., Walley S.M., Proud W.G. and Field J.E. (2004) "Behaviour of ammonium perchlorate-based propellants and a polymer-bonded explosive under impact loading" Proc. R. Soc. Lond. A460 781-806