GSPD: An algorithm for time-dependent tokamak equilibria design

TL;DR

The paper introduces GSPD, an algorithm that designs time-dependent tokamak plasma equilibria by solving the Grad-Shafranov equation while accounting for dynamic effects like plasma current drive and vessel currents.

Contribution

GSPD is the first algorithm to compute sequences of equilibria incorporating both force balance and circuit dynamics in a time-dependent manner.

Findings

Successfully models plasma equilibria with dynamic effects.

Provides an open-source tool for tokamak equilibrium design.

Enables more realistic plasma scenario simulations.

Abstract

One of the common tasks required for designing new plasma pulses or shaping scenarios is to design the desired equilibria using an equilibrium (Grad-Shafranov equation) solver. However, standard equilibrium solvers are time-independent and cannot include dynamic effects such as plasma current drive, induced vessel currents, or voltage constraints. In this work we present the Grad-Shafranov Pulse Design (GSPD) algorithm, which solves for sequences of equilibria while simultaneously including time-dependent effects. The computed equilibria satisfy both Grad-Shafranov force balance and axisymmetric conductor circuit dynamics. The code for GSPD is available at github.com/plasmacontrol/GSPD.