The research status of induced radioactivity in accelerator facilities

The hazards of subsequent-radiation produced by high-energy accelerator must be no ignore. The principle of induced radioactivity and the hazards to the people were introduced in this article. The radiation levels around the treatment head and in the air of the treatment room were discussed thor-oughly. Some effects of the induced radioactivity were also mentioned. At last, the article talks about some problems in present researches and some directions for the following study. (authors)