Radiation shielding near a controlled fusion research facility: the Fontenay-aux-Roses tokamak T.F.R

This report presents the results of X-ray and neutron dosimetry measurements near the magnetic confinement device for hot plasmas known as T.F.R. (Tokamak, Fontenay-aux-Roses). The biological shielding consists of an ordinary concrete wall 30 cm thick; the dose rate is thus limited to 10-1 mrem per discharge or approximately 10 mrem per day throughout the area frequented by people during operation of the T.F.R. Numerical calculations allowing for the true geometry and X-ray reflection from the walls and roof, and normalized to the measurements, give the characteristics of the electron beam which is the source of this radiation. Photoneutron generation (up to 1010 neutrons per discharge) and activation of the vacuum vessel are caused by high-energy electrons (>= 10 MeV) carrying a current of 10-1000 A. (author)