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
British nuclear tests at Maralinga nuclear warheads containing plutonium-239. In total, "Vixen B" scattered 22.2 kg of plutonium around the Maralinga test site known as Taranaki, in particles of widely divergent size. Plutonium is not particularly dangerous externally - it emits alpha particles which are stopped by of air, or the dead layer of skin cells on the body, and is not a very intensive source of radiation, due to its long half-life of 24,000 years. It is most dangerous when it enters the body, in the worst case by breathing, and therefore tiny particles, often the result of such explosion testing, are the worst