Boundary physics experiments in tokamaks

点击翻译按钮获取中文摘要

Fusion energy research aims to harness the same process that powers the sun and stars. Research is carried out in large governments labs in all G8 nations except Canada. The Applicant carries out his research by collaborating with researchers in a number of these labs, generating projects to be undertaken by himself, his graduate students and research associates at the University of Toronto. OEDGE is a large computer code developed by the Applicant and his Toronto group for interpretive modeling of the behaviour of the hot plasma at the edge of the magnetic confinement fusion devices such as tokamaks, where plasma interaction with the solid structure ('wall armour') occurs. OEDGE is now used by a number of the major fusion labs in Europe and the US. Fusion research has entered a new phase with the decision in June 2005 to site the $10 billion ITER tokamak project in France. ITER is being built by an international consortium of industrial nations to demonstrate the scientific feasibility of fusion energy. ITER will 'burn' tritium, a substance which occurs only in small quantities in nature. Canada's CANDU fission reactors produce tritium as an unwanted by-product at the rate of a few kg/year, making Canada the main source of commercial tritium in the world. ITER's operational plans are based on the availability of Canadian tritium. ITER will require most of Canada's production over the next several decades, more than 10 kg, worth $10-100 million/kg. When the present generation of carbon-armoured fusion devices was operated with tritium, it was found that about half of the tritium introduced into the machine was retained in the vessel in carbon co-deposits and could not be readily recovered. Extrapolation to ITER indicates that 1 kg of tritium could be tied up in this way after a few day's operation. Since the permitted in-vessel tritium inventory in ITER is only 0.35 kg this poses a serious problem. With the aim of solving this tritium retention problem, the proposed research will involve the Applicant's group proposing, designing and carrying out experiments in the DIII-D tokamak in the US, also interpreting them with our OEDGE code.