Ernest Lawrence a scrap of a paper napkin. While sitting in the library one evening in 1929, Lawrence glanced over a journal article by Rolf Widerøe, and was intrigued by one of the diagrams. This depicted a device that produced high-energy particles by means of a succession of small "pushes". The device depicted was laid out in a straight line using increasingly longer electrodes. At the time, physicists were beginning to explore the atomic nucleus. In 1919, the New Zealand physicist Ernest Rutherford had fired alpha particles into nitrogen and had succeeded in knocking protons out of some of the nuclei. But
Nitrogen-13 proton needs to carry extra energy to produce the nuclear reaction. The energy difference is actually 5.22 MeV, but if the proton only supplied this energy the reactants would be formed with no kinetic energy. As momentum must be conserved, the true energy that needs to be supplied by the proton is given by: Nitrogen-13 plays a significant role in the CNO cycle, which is the dominant source of energy in stars heavier than the Sun. Lightning may have a role in the production of nitrogen-13. Nitrogen-13 Nitrogen-13 is a radioisotope of nitrogen used in positron emission tomography (PET). It