Speaker
Description
In the framework of magnetic reconnection studies, and in collaboration with EUROfusion partners, we study how the presence of a large magnetic island, like the ones due to a (neoclassical) tearing mode in a tokamak, changes the transport in radial direction (core to edge and vice versa) [1]. The general purpose is to study the interplay between such an island and the accumulation of tungsten in the core. The problem became recently of interest because on one side the new ITER baseline foresees the whole inner wall covered in tungsten [2] and on the other because experimental data in various tokamaks show an accumulation of tungsten in the core in presence of a magnetic island. The technique is to implement in transport codes like ASTRA and JINTRAC an opportune modification of transport coefficients in the island position and as large as the island width, as measured in the experiment, and to analytically estimate the value of the coefficients in the island [2].
In collaboration with the NEMO group at Politecnico di Torino and with EUROfusion partners, we study the presence of impurities inside a tokamak in case in which innovative components are considered for the first wall. In particular we study the behaviour of tungsten in the Volumetric Neutron Source (VNS), foreseen to be a beam-driven tokamak aiming to test in-vessel components under high-neutron flux[3], and of tin inside AUG in an experiment performed to understand how Liquid Metal Divertors (LMD) tokamaks would perform.
Here, we present the main results achieved so far and outline our ongoing activities.
References:
[1] C. Marchetto et al to be submitted to Physics of Plasmas
[2] C. Marchetto et al Invited at 1st ECMRP, Marseille, 23-26 May 2023
[3] E. Bray Oral at TTF-EU, Budapest, 9-12 September 2025
[4] E. Bray To be submitted to Nuclear Materials and Energy
