Explosive plane-wave generator

Various other explosive plane-wave generators have been designed (Deal, 1962 Fowles, 1972), but they all make use of an angular relation which... 

Figure 3.2. Explosive plane-wave generator used to accelerate a flyer plate for planar impact on a specimen.

The peak pressures attainable with explosive facilities can be greatly enhanced, and the initial peak pressure can be better sustained by using a plane-wave generator to accelerate a flyer plate, which then impacts a flat specimen as shown in Fig. 3.2. This technique will generate peak pressures up to a few hundred GPa. (McQueen and Marsh, 1960 McQueen et al., 1970). 

The high explosives, baratol or Composition B-3, are used to produce the plane wave loading into the driver plates. These explosives have been widely studied in substantial work at Los Alamos. Plane waves are introduced into the explosive pads with either P-22 or P-40 plane-wave generators developed at Los Alamos. The Bear system is based on the 56 mm diameter of the P-22, while the larger sample size Bertha system is based on the 102 mmdiam of the P-40. More details on sample dimensions are reported by Graham [87G03]. 

Fig. 10.3 Generation of high dynamic pressures with chemical explosives (a) cylindrical scheme, (b) planar direct-contact scheme, (c) planar scheme with explosively accelerated impactor plate. 1 detonator, 2 explosive, 3 ampoule, 4 sample, 5 plane wave generator, 6 layer of inert material, 7 impactor plate...

Figure 1.8. Plane wave generator with two explosives of differs detonation velociti ...

Three types of plane wave generators for explosive systems used in generating dynamic material properties make use of the properties of Baratol and Composition B to form effective lenses. Baratol s slow detonation velocity and Composition B s high detonation velocity, if used in the proper configuration, can convert a spherically diverging wave into an approximate plane wave. The P-40, P-081, and P-120 lenses were used until the middle 1990 s. 

A plane shock wave generating apparatus consists of a hanging cone, in which a low detonation velocity explosive of nitromethane or nitromethane mixture is filled, and an encapulsated space outside the cone, in which a ternary high detonation velocity liquid explosives of hydrazine nitrate/hydrazine/water is filled [33, 34]. 

Fig. 1. Generation of the sequence of shock waves at underwater explosion of a spatial (a) and plane (b) spiral.

---