Modeling non-axisymmetric magnetic fields produced by ELM control coils in TCABR

• Grant number: 25/12216-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2025
• End date: August 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Physics - Physics of Fluids, Plasma Physics and Electrical Discharge
• Principal Investigator: Gustavo Paganini Canal
• Grantee: Ryan Augusto de Oliveira Nalesso
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 22/04857-2 - Development of an innovative set of ELM control coils for the TCABR tokamak, AP.JP

Abstract

A significant upgrade of the Tokamak à Chauffage Alfvén Brésilien (TCABR) is being designed to make it capable of creating a well controlled environment where the physics basis behind the effect of externally applied magnetic perturbations on edge localized modes (ELMs) can be addressed over a wide range of plasma scenarios, ELM control coil geometries and perturbed magnetic field spectra. The core of this upgrade corresponds to the design and construction of an innovative set of in-vessel ELM control coils composed of six toroidal arrays of coils equally spaced in the toroidal direction, three on the high field side and three on the low field side. Each array will be composed of 18 coils, i.e. a total of 108 coils will be installed inside the TCABR vacuum vessel. Due to its relatively high number of coils, this set will allow for the creation of perturbation fields with toroidal mode number as high as n = 9. Modeling the vacuum magnetic field produced by these non-axisymmetric coils is, therefore,a fundamental step for their design and also for their use during future experiments. To estimate the vacuum magnetic field produced in the plasma region by this set of coils, the geometry of the conductors of each coil will be modeled using sufficiently small rectilinear segments of current. Subsequently, the magnetic field created by each segment will be calculated using the Biot-Savart law. With both the geometry and the electric current of each coil being fixed, the magnetic field distribution inside the TCABR vacuum vessel will be calculated. The result of this development will be incorporated into a set of tools for the future use of the TCABR ELM control coils system.