Understanding and suppressing dark current generation is an important part of designing a variety of high-field-gradient structures, including radio-frequency electron guns, slow-wave structures, and power feed systems. Presently, dark current modeling is needed for the design of the Machine Protection System for International Linear Collider Main Linac. In previous work, a prototype modeling capability was created that includes RF field calculation, field emission, secondary emission, particle visualization, and a simple particle spectrometer. This project will complete a comprehensive capability for dark current particle tracking within this software package, in preparation for its use by the accelerator community. Phase I will involve expanding support for field emission and secondary emission models, making enhancements to the 3D particle tracker, and enabling a 2D capability. Commercial Applications and other Benefits as described by the awardee New high-energy physics accelerators are very expensive to design and build; therefore, a capability to predict and correct potential failure mechanisms early in the design process should have a substantial impact on overall machine development costs. Anticipated public benefits include lower development costs for new high-energy particle colliders, as well as for commercial accelerators such as those used in the medical industry