A Direct Experimental Determination of Electron Affinities, the Electron Affinity of Iodine

摘要

By observing the ratio of the negative ion emission to the electron emission from a thermionic surface of known temperature in an atmosphere of electronegative molecules of known pressure the electron affinity of the atoms can be calculated. A magnetron set up has been used to distinguish electron and ion currents. With a tungsten filament at about 2000°K, and an iodine atmosphere of about 1 micron pressure, the electron affinity of iodine atoms has been found to be 72.4±1.5 kcal.