October 10, 2022
Plasma density as the main lever to controlling fusion reactors
Saskia Mordjick, Associate Professor, College of William & Mary
Abstract: Fusion energy promises to produce clean and safe electricity on a large scale, but it still faces some challenges.). The fusion gain in a tokamak is directly linked to the density of the plasma. However, due to the high temperatures and densities, it impossible to fuel the plasma core in a fusion reactor, as all neutral particles will ionize at the edge of the device. Without any direct fueling in the core of a tokamak, the plasma density is fully controlled by transport perpendicular to the confining magnetic field surfaces. In this talk I will show how cross-field transport is dominated by turbulence in the plasma core by comparing experiments with existing models. These models capture how various types of turbulence influence transport and thus the density profile. While the density profile in the core is fully determined by turbulent transport, at the plasma edge, the picture is more complicated. At the edge of the tokamak, turbulent transport effects intermingle directly with fueling through ionization of the surrounding gas. Sustaining a high-density plasma, which is opaque to neutrals is not dissimilar to a minority navigating the fusion and plasma community. The talk will be interwoven with personal experiences, statistics and best practices to achieve a healthy fusion community and reduce the opaqueness for minorities to succeed.