Next Step Fusion Simulator
NSFsim is an advanced Grad-Shafranov 2D solver designed for simulating and controlling free-boundary plasma equilibrium in tokamaks. It efficiently couples plasma evolution with external circuits, conducting structures, and magnetic diagnostics, providing accurate and reliable predictions across various control scenarios. NSFsim is based on the renowned DINA simulation approach and a modular architecture that has been extensively tested on numerous tokamaks.
Simulations of DIII-D, ISTTOK, NSF NTT, SMART, and other tokamaks, using NSFsim and other codes, are available to the fusion community on the Fusion Twin Platform, a web service for running tokamak simulations and managing fusion data in the cloud.
Simulations of DIII-D, ISTTOK, NSF NTT, SMART, and other tokamaks, using NSFsim and other codes, are available to the fusion community on the Fusion Twin Platform, a web service for running tokamak simulations and managing fusion data in the cloud.
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Tokamak Digital Replica
Solving all the equations together in a self-consistent manner requires the introduction of a mathematical abstraction of real devices. This is known as a configuration or digital replica, unique to each tokamak. The digital replica is based on the geometrical and electrical characteristics of the magnetic system and passive conducting structures, including poloidal field coils, the vacuum vessel, and the limiter. The calculation domain is represented by a mesh that can vary for each element. -
Magnetic Diagnostics
For plasma shape and position control, magnetic diagnostics such as magnetic probes and flux loops are essential. Synthetic signals of those sensors are calculated considering the mutual magnetic fields arising from toroidal currents in plasma, active, and passive elements. Read more about the validation and verification of synthetic magnetic diagnostics in the blog post. -
Accurate Predictions
By considering factors such as thermal conductivity, compression, and electron drift, NSFsim can accurately predict plasma evolution and solve reverse tasks, providing a comprehensive understanding of tokamak operations. This approach allows us to simulate the intricate details of plasma physics, magnetic fields, energetics, and control mechanisms. -
Variety of Scenarios
NSFsim is leveraged for myriad purposes, including simulation, experiment planning, disruption prediction and analysis, research, and crucially, for training machine learning (ML) models designed for plasma control and behavior prediction by simulating complex plasma behaviors and dynamics to provide an essential environment for developing advanced control systems.
