X-ray imaging studies of Alcator-A radiation and internal disruptions

Soft-X-ray data collected with an imaging system on the Alcator-A tokamak are used to study characteristics of quasi-equilibrium plasma radiation, and a method of using soft-X-ray data to determine the electron-temperature-profile change due to internal disruptions is described. It is found that, for a series of discharges characterized by increasing plasma density, X-radiation from the plasma core becomes more like hydrogen bremsstrahlung. For the highest-density discharges studied, local-X-ray enhancement factors are approximately 1, within the central half of the plasma column. Finally, the change in the electron temperature profile due to internal disruptions which occurred during a high-density discharge is determined.