The discovery of natural radioactivity at Poitiers assessment of a teaching experiment

In order to make secondary school pupils discover natural radioactivity, the author presents the scientific and teaching assessment of two experiments: the radon measurements in houses around the city of Poitiers; the mapping of Poitiers surroundings by the gamma radiation measurement. The experiments and the analysis of the results have been made by the students under the leadership of their teachers. The help of professional in radiation protection has allowed to conclude these experiments. The quality of results in these two experiments show that when different people combine their efforts, high school can be a great experiment field. (N.C.)