ABSTRACT
The general method has proved very convenient for studying the transmutation of elements by protons of energy between 20,000 and 200,000 volts. The success of such experiments largely depended on the adequacy of the pumping system to obtain steady conditions in the discharge tube. Fast pumping is required and it is desirable to use oil rather than mercury diffusion pumps as mercury seems to promote autoelectronic discharges from the electrodes. The discharge tube was freed from occluded gases by running for a long time, first without and then, as it hardened, with hydrogen flowing in. It was found to be most easy to degas the main accelerating electrodes and tube by admitting hydrogen till it was possible to run a discharge at about 20-60 kilovolts. In addition they have measured the voltage variation of the number of particles emitted from a thin film of Li in the form of oxide.
