Plane Wave Lens

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. 

Each plane wave generator is designed to produce a plane shock wave at the upper Baratol surface of the device. The generators use the lens effect of a Baratol cone, and the lower transit velocity therein, to mold the somewhat spherical spreading detonation waves into planar patterns as they proceed. 

Each of the plane wave lens was modeled using the 2DE code. A radiographic study of the plane wave lens is presented in reference 5. 

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The new variant is as follows Copper cylinders 25.4mm (or 50.8mm) diam 12 inches long, of various thicknesses, were filled with HE s to test. A plane wave lens and Comp B, Grade A (64/36-RDX/TNT)... 

The x-ray beam axis is perpendicular to the direction of detonation in a 10 cm cube of Composition B-3 explosive (the HE) which is initiated by a large diameter plane-wave lens. (Since the machine can be flashed only once during the passage of the detonation wave, the time sequence is obtained from repeated experi-... 

The booster-and-attenuator system is selected to provide about the desired shock pressure in the sample wedge. In all but a few of the experiments on which data are presented here, the booster-and-attenuator systems consisted of a plane-wave lens, a booster expl, and an inert metal or plastic shock attenuator. In some instances, the attenuator is composed of several materials, The pressure and particle velocity are assumed to be the same on both sides of the attenuator-and-sample interface. However, because initiation is not a steady state, this boundary condition is not precisely correct. The free-surface velocity of the attenuator is measured, and the particle velocity is assumed to be about half that. The shock Hugoniot of the attenuator can be evaluated using the free-surface velocity measurement. Then, the pressure (P) and particle velocity (Up) in the expl sample are found by determining graphically the intersection of the attenuator rarefaction locus and the explosives-state locus given by the conservation-of-mom-entum relation for the expl, P = p0UpUs where Us = shock velocity and p0 = initial density. The attenuator rarefaction locus is approximated... 

Another test which shows considerable promise for exploring time-dependent adia-bats with small amts of expl is the cylinder test. The std cylinder test geometry consists of a 1 inch diam, 12 inch long expl chge fitted into a Cu tube with a 0.1022 inch thick wall. A plane wave lens and 0.5 inch thick Comp B booster are used to initiate the test expl at one end. The radial motion of the cylinder wall is measured in a plane perpendicular to the cylinder axis 7 inches from the booster end. A streak camera records the motion, using conventional shadowgraph techniques. In addn, the deton vel of the expl is measured by placing pin switches 9 inches apart on the surface of the cylinder (Ref 2)... 

Figure 4.13 Static and dynamic radiographs NW-423 of a 10.16 cm cube of Composition B explosive initiated by a plane wave lens and confined by 2.54 cm thick plates of Aluminum.

Figure 4.17 PHERMEX static and dynamic radiographs of shot NW-1942 for a corner of X-0219 with a Plexiglas plate initiated by a plane wave lens. The corner region of undecomposed X-0219 is shown.

Figure 5.35 The calculated density contours for a P-040 plane wave lens after 2.625 jusec. The circles mark the experimental points read from the radiograph from Shot 630.

Plane Wave Lens - TDL Calculation PIOO.MVE - TNT/PBX-9501 Plane Wave Lens... 

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