Modeling Desensitization of Condensed Phase Explosives for Shock-Detonation Interactions

Insensitive condensed phase explosives, such as PBX-9502, rely on mesoscale void collapse and subsequent hot spots to initiate detonation. If the voids are compressed, the mechanism for generating hot spots in the material is lost, leaving the material effectively inert. This process of compacting the material and collapsing the voids without initiating detonation is referred to as desensitization. Often this process is initiated via a weak shock. Though not definitive, it is generally believed that the weak shock causes the voids to collapse, but diffusion of the hot spot is more rapid than the reaction timescales. Here, we propose to collect and review the experimental observations associated with this desensitization process. We will show that a model for desensitization should: (1) occur over a finite timescale, (2) allow for partially burned material, and (3) both suppress initiation and induce detonation failure. Furthermore, we will review the conventional models related to desensitization, focusing on these three desired phenomena. Finally, the models will be extended as necessary to capture the desired effects, and an experimental framework will be presented to improve calibration of said model based on shock-detonation interactions.