FyTok: An integrated modeling simulator for magnetic confinement fusion Tokamak

The tokamak is a highly complex system consisting of a large number of subsystems. It involves a wide range of non-linear physical processes on a variety of spatial and temporal scales. These physical processes are independent but closely interrelated. Therefore, the description and comprehension of the whole system is a very complicated endeavour. Existing single-function simulation codes are highly accuracy at certain specific spatial and temporal scales. However, separate analytical methods are insufficient to describe the multi-scale and non-linear characteristics of complex systems. It is therefore essential to adopt an appropriate “ integration” strategy to improve the understanding of complex systems. This paper describes the development of FyTok, a comprehensive simulator for the magnetic confinement fusion tokamak. The simulator has been designed using a top-down approach with ontology-based modeling, which translates the tokamak ontology description based on IMAS DD into a manipulable programming framework. The modeling objects in FyTok are divided into subsystems and plasma states in FyTok. FyTok handles each of these separately using data bindings, formula bindings and function bindings. FyTok can be easily configured using configuration files to organise the different module classes, generate the required physical workflows, and track the evolution of physical quantities in the workflows for modeling purposes. The ontology-based modeling approach in FyTok improves data consistency and provides the user with a generic and flexible modeling platform.