Overcoming LX-17 Failure Diameter Size by High Pressure Shock Initiation using Ultra Fast, Thin, Small Diameter Flyer Plates

摘要

The shock initiation of a condensed phase explosive by a detonator/booster system is often limited by its unconfined failure diameter, below which a self-sustaining detonation cannot propagate. Very thin, small diameter flyer plates driven to extremely high velocities have recently been shown to have the capability to initiate relatively shock sensitive solid explosives at diameters considerably smaller than their failure diameters. In this paper, Kapton flyers with diameters as small as 5 mm are used to shock initiate the insensitive high explosive LX-17 (92.5% TATB / 7.5% Kel-F binder), which has an unconfined failure diameter of 11 - 12 mm. Flyer velocities that impart shock pressures far in excess of the LX-17 von Neumann spike pressure are required. Measured threshold flyer velocities of Kapton flyers of various diameters and thicknesses that shock initiate LX-17 at 25°C, 75°C, 150°C and 250°C LX-17 are reported. The LX-17 Ignition and Growth model is used to simulate this two-dimensional process in which diverging detonation wave development is hindered by both rear and side rarefaction waves.