Status of Lab-scale Asynchronous Radiography of Spontaneous Thermal Explosions and Detonations

The Lab-scale Asynchronous Radiography System (LARS) facility at Los Alamos has been evolving in capability over the past decade and has been applied to problems of materials in extremes ranging from slow thermal phase changes to the initiation of detonation. By trading off spatial resolution, time resolution, field of view, and contrast sensitivity, the system is able to capture continuous movies of x-ray transmission over broad ranges of time resolution and event duration. At one extreme, it has been used with 50 micron spatial and 10 ms time resolution to follow solid-solid and solid-liquid-gas transitions in explosives heated from room temperature through to thermal explosion. At the other end of the spectrum, it has been applied with few hundred micron spatial resolution and hundreds of nanosecond time resolution to observe the initiation of detonation in a commercial EBW detonator. A summary of the capability and current applications and future directions will be discussed.