Dose Measurement and Analysis of EAST in the 2007 Spring Experiment

The radiation generated by EAST in the 2007 spring experiment was mainly photons and a few photoneutrons. In order to measure and analyze the radiation field of the EAST device, 6LiF(Mg,Cu,P) and 7LiF(Mg,Cu,P) thermoluminescence detectors (TLDs) were applied to determine the photon and neutron dose equivalent distributions in the EAST hall, the central control room and the surrounding environment. The measurement results showed that the accumulated doses equivalent and the estimated average dose rates equivalent in the tokamak hall were very high during the whole experiment period and the discharge period, respectively. So any personnel accessing into the hall or staying in the hall during the plasma discharge periods should be prohibited automatically by the safety interlock. The doses equivalent in the central control room and the surrounding environment during the experiment period were just a little higher than the background level, and the dose influence on the staff and the ambient inhabitants was slight except the entrance areas of the EAST hall, where very high photon and neutron doses equivalent appeared. Effective measures should be carried out in the entrance areas as soon as possible to reduce the radiation levels during discharge periods.