Fusion Energy: Plasma Materials Interactions Lab

Research Overview

The fuel in fusion reactors is a mixture of deuterium and tritium – the heavy isotopes of hydrogen. Fusion reactions occur at about 100 million degrees. At this temperature the fuel is in the plasma state. While magnetic fields confine the hot core plasma to the centre of the reactor vessel, the cooler edge plasma will contact the reactor walls, resulting in physical and chemical phenomena with potential engineering implications. Research at UTIAS focuses on the study of plasma-materials interactions with ITER-specific materials, namely, carbon, tungsten and beryllium. Current research includes studies of (i) materials erosion, in particular, chemical erosion and high temperature erosion processes, (ii) diffusion, trapping. and retention of hydrogen isotopes in carbon, tungsten, and mixed materials, (iii) the recovery of deuterium (in the case of ITER it will be deuterium and tritium) from layers of D-containing deposits formed in tokamaks. Using our dual-beam ion accelerator, we also study surface modification and composition dynamics during simultaneous irradiation of surfaces by two plasma species, e.g., D and He, D and C, D and O, where D is the fuel and He, C and O are impurities in the plasma.

One of the main technological challenges associated with fusion reactor R&D is the development of new materials capable of existing in the fusion plasma environment. We study plasma-materials-interaction processes using plasma simulation facilities where candidate reactor materials are tested under controlled conditions. These facilities consist of ultrahigh vacuum systems and plasma particle beams, including sub-eV hydrogen, electrons, and energetic hydrogen and other ions. Diagnostics include quadrupole mass spectrometers, residual gas analyzers and a laser-thermal-desorption apparatus for hydrogen retention measurements. We also have access to surface analysis facilities elsewhere at the University of Toronto.