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-15 nuclear magnetic resonance spectroscopy Nitrogen-15 nuclear magnetic resonance spectroscopy Nitrogen-15 nuclear magnetic resonance spectroscopy (nitrogen-15 NMR spectroscopy, or just simply N NMR) is a version of nuclear magnetic resonance spectroscopy that examines samples containing the N nucleus. N NMR differs in several ways from the more common C and H NMR. To lift the restraint of spin 1 found in N, N NMR is employed in samples for detection since it has a ground-state spin of ½. SinceN is 99.64% abundant, incorporation of N into samples often requires novel synthetic techniques. Two sources of nitrogen-15 are the positron emission of oxygen-15 and the beta