Nobel prize to E. O. Lawrence awarded in 1939 "for the invention and development of the cyclotron and for results obtained with it, especially with regard to artificial radioactive elements''
Lawrence, E.O.; Livingston, M.S.; A Method for Producing High Speed Hydrogen Ions without the Use of High Voltages
Phys. Rev. 37 (1931) 1707;
A method for producing high speed hydrogen ions without the use of high voltages was described at the September meeting of the National Academy of Sciences. (Science 72, 376 (1930)) The hydrogen ions are set in resonance with a high frequency oscillating voltage between two hollow semicircular plates in a vacuum, and are made to spiral around in semicircular paths inside these plates by a magnetic field. Each time the ions pass from the interior of one plate to that of the other they gain energy
corresponding to the voltage across the plates. This method has now been tried out with the following results: Using a magnet with pole faces 10 cm in diameter and giving a field of 12700 gauss, 80000 volt hydrogen molecule ions have been produced using 2000 volt high frequency oscillations on the plates. A voltage amplification (the ratio of the equivalent voltage of the ions produced to the high frequency voltage applied to the plates) of 82 has been obtained. These preliminary experiments indicate
clearly that there are no difficulties in the way of producing one million volt ions in this manner. A larger magnet is under construction for this purpose.
Related references More (earlier) information appears in E. O. Lawrence and W. E. Edlefsen, Science 72 (1930) 376;
More (later) information appears in E. O. Lawrence and M. S. Livingston, Phys. Rev. 40 (1932) 19;
E. O. Lawrence and M. S. Livingston, Phys. Rev. 38 (1931) 834;