Formation of 211Rn by 6Li induced reactions on 209Bi at 70 MeV

Besides spallation reactions on heavy target materials such as thorium and uranium, Li induced reactions on 209Bi represent the only feasible pathway for a direct formation of Rn isotopes. 211Rn is of special interest because it represents the only source for nucleogenic 211At atoms. While in earlier experiments 7Li induced reactions gave quite satisfying yields of 211Rn, the current investigation showed, that 6Li beams are far less useful for production of 211Rn, because of the instability of the projectiles. Break-up of 6Li in the coulomb field of the targets or degrader foils lead to the observation that deuteron and alpha induced reactions dominate the product spectrum. The 211Rn yield in thick targets reached only 20% of the yield reported for 7Li induced reactions. (orig.)