Abstract
Kinetic Inductance Detectors (KIDs) are an emerging technology useful for a wide variety of astronomy applications, including the Habitable Exoplanet Imaging Mission (HabEx), the Origins Space Telescope (OST), the Probe of Inflation and Cosmic Origins (PICO), and more. KIDs operate at cryogenic temperatures and can detect photons with high accuracy, sensitivity, and over a wide range of wavelengths. Though many KID models describe their performance well under certain operating conditions, some important pieces of physics related to quasiparticle dynamics are not yet either well understood or integrated into these models and can strongly affect device performance. In this paper we describe our framework for building an extended KID model, present the results of a quasiparticle diffusion simulation that incorporates scattering, cooling and diffusion, and discuss plans for the experimental testing of the model. We also discuss additional features to be added into future models that aim to capture a wide variety of potential scenarios encountered by researchers.