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
Liquid nitrogen liquid nitrogen. Liquid nitrogen is produced commercially from the cryogenic distillation of liquified air or from the liquefication of pure nitrogen derived from air using pressure swing adsorption. An air compressor is used to compress filtered air to high pressure; the high-pressure gas is cooled back to ambient temperature, and allowed to expand to a low pressure. The expanding air cools greatly (the Joule–Thomson effect), and oxygen, nitrogen, and argon are separated by further stages of expansion and distillation. Small-scale production of liquid nitrogen is easily achieved using this principle. Liquid nitrogen may be produced for direct sale, or as