Integrated EM & thermal simulation with VORPAL software

The VORPAL finite-difference time-domain particle-in-cell simulation tool now has thermal solver capability, which we are using to model transmission lines and accelerating cavities of cryogenic SRF accelerators. This same capability can be brought to bear on room temperature problems EM and Thermal physics. Our thermal solver treats the non-linear evolution of the material properties, such as electrical and thermal conductivity. We have recently upgraded our thermal solver to allow for implicit solves with larger time-steps, consistent with problems having material interfaces with drastically different (~10⁵) thermal conductivities. We present benchmarks of integrated problems including a coaxial feed-through into a high-order mode coupler, and time-domain modeling of cryogenic quench events.