摘要: A brief account of the present status tokamak performance is given, followed by a description properties ideal thermonuclear neutron source. The very comprehensive range measuring systems installed at particular installation (The Joint European Torus) then presented, along with some typical illustrative results. Some exceptional results are also presented to indicate manner in which actual source deviate from ideal, since identification such situations essential prevent wrong interpretation being placed upon most basic measurement, that total yield. Areas quality either nuclear data or techniques employed deemed be unsatisfactory will highlighted course presentation.