Cygnus Trigger System

Summary form only given. The Cygnus Dual Beam Radiographic Facility consists of two identical radiographic sources each with a dose rating of 4 rad at 1 m, and a 1 -mm diameter spot size. The electrical specifications are: 2.25 MV, 60 kA, 60 ns. This facility is located in an underground environment at the Nevada Test Site (NTS). These sources were developed as a primary diagnostic for subcritical tests, which are single-shot, high-value events. In such an application there is an emphasis on reliability and reproducibility. robust low-jitter trigger system is a key element for meeting these goals. The trigger system was developed with both commercial and project-specific equipment. In addition to the traditional functions of a trigger svstem there are novel features added to protect the investment of a high-value shot. Details of the trigger system, including elements designed specifically for a subcritical test application, will be presented. The individual electronic components have their nominal propagation delav, and when assembled have a svstem propagation delay with a measured range of jitter. The shot-to-shot jitter will be assessed both individually and in combination. Trigger reliability and reproducibility results will be presented for a large data base of shots executed at NTS.