January 2007
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Xyce Electrical Modeling and Simulation to Support Weapons Qualification

In FY07, the Xyce circuit modeling application was used to generate simulation results in support of weapon components qualification efforts. To provide the greatest impact to qualification, the simulations focused on performance issues surrounding critical electronic subsystems. The circuit model has been enhanced to simulate relevant realistic scenarios by adding parasitic elements and initial conditions. The simulations provide additional qualification evidence by confirming design margins, giving access to circuit response measures not available during tests, and allowing for simulation of realistic hostile radiation scenarios that cannot be tested. The simulation results show good agreement with available test data, and validation efforts are under way in FY07, including several novel validation experimental activities.

The goal of the Xyce team is to provide distinctive capabilities in the area of circuit simulation through large-scale parallel computing, predictive transient-radiation device-models and combined (x/gamma ray, neutron, temperature) effects to weapons designers at Sandia. This suite of attributes is absolutely unique and has been specifically developed to support the unique mission-space of Sandia’s electrical design and qualification community. The inclusion of these results in qualification documentation represents a major accomplishment towards that goal.

figure 1

Figure 1. Simulation showing total photocurrent created in a critical electronic subsystem as a result of an ionizing radiation event. This total photocurrent response cannot be measured during a test.

Figure 2

Figure 2. Ionizing radiation simulation showing good agreement with measured data for a critical circuit response measure and confirming design margins.