Neutron Experiments of the Physical Laboratory of Groningen

Abstract

IN the beginning of 1940, a few months before the occupation of Holland by the Germans, we started some neutron experiments in this Laboratory (see ref. 1). To determine neutron energies the well-known boron absorption method was applied. Following Frisch's example², boron was used not as a compound but in the pure amorphous state. This boron arrived in March 1940 in Groningen from the British Drug Houses, Ltd. As it yielded nearly the same results as a sample of amorphous boron from Merck (Germany) which we had still in the laboratory, we had not the slightest suspicion that our results could be spoiled by too high an amount of impurities.