"BREAK" OF THE ACTIVATION CURVES OF FLUORINE AND NITROGEN BY PHOTONEUTRON REACTION

With a new system of counting, the threshold and the "breaks" of the activation curves of the reactions N/sup 14/ ( gamma ,n)N/sup 13/ and F/sup 19/( gamma ,n)F/sup 18/ were determined. New "breaks" were found. The counting of the beta /sup +/ activity of N/sup 13/ and F/sup 18/ were done in coincidence with two large NaI(Tl) crystals. (tr -auth)