Ricerca CERCA

Eddy currents power deposition in DTT TF coil casing due to PF/CS current evolution during plasma scenario

Reference persons ROBERTO BONIFETTO

External reference persons Marco De Bastiani

Research Groups Nemo

Description Problem description:
To assure plasma confinement and stability in a tokamak-type fusion reactor, suitable magnetic field evolution is required​. Therefore, during plasma scenario the current in the pulsed coils (poloidal field, PF, and central solenoid, CS) are not constant. Such a current evolution generates a time dependent magnetic field that induces eddy currents in the conductive regions (Ampère’s + Faraday’s Law) such as the TF coil casing​. The eddy currents deposit Joule power in the coil structures, causing a heat generation close to the superconductors, with possible erosion of their temperature margin​.
It is therefore important to evaluate the power deposition by means of electro-magnetic (EM) simulations using the PoliTo tool 3DFOX [R. Bonifetto M. De Bastiani, R. Zanino, A. Zappatore, 3D-FOX – a 3D Transient Electromagnetic Code for Eddy Currents Computation in Superconducting Magnet Structures: DTT TF Fast Current Discharge Analysis, IEEE Access, 2022], and assess the impact of such power on superconducting magnet performance by a thermal-hydraulic (TH) simulation (using the PoliTo 4C code [L. Savoldi Richard, F. Casella, B. Fiori, R. Zanino, The 4C code for the cryogenic circuit conductor and coil modeling in ITER, Cryogenics, 2010])​.
Thesis structure:
1) Introduction on FreeFem++ scripting language + introduction to 3D-FOX​
2) Preparation of the computational domain and meshing​
3) EM simulation with 3D-FOX* for the evaluation of the eddy currents and power deposition
4) Using of EM results as input to TH simulations (4C code) including​ AC losses impact (knowing current evolution)​
*Code Development: optimization of the domain​ decomposition strategy for periodic spherical edge domains in​ 3D-FOX

See also  thesis_proposal_eddycurrents_dtt_plasmascenario.pdf 

Deadline 03/10/2024      PROPONI LA TUA CANDIDATURA