The transmutation of fluorine by protons
The excitation functions for the production of long range alpha-particles, gamma-rays, and electron pairs by the bombardment of F19 by protons have been observed simultaneously up to a bombarding energy of 1.5 Mev. The long range alpha and pair curves exhibit resonance peaks superimposed on a background of increasing intensity with increasing bombarding energy. Approximate coincidence in two instances of pair and alpha-resonances suggests that full range alphas and the short range alphas preceding pair emission can be products of competing modes of decay of the same intermediate states of Ne20. This in turn suggests that the state of O16 which decays by pair emission has the same parity (even) as the ground states of O16 and thus that the pair emission can be due to ordinary electromagnetic forces. The absolute yields of the various processes have been measured and a discussion of the measurement of high energy gamma-ray and pair yields by means of electroscopes is given. The large ratio of gamma-ray yields to long range alpha and pair yields previously observed has been confirmed.