Energy ofKα3of Copper as a Function of Applied Voltage with the Double Crystal Spectrometer

With a double crystal spectrometer of special design here briefly described the following questions were investigated with a view to determining the origin of the satellite $K{\alpha }_3$ of copper. (1) Dependence of intensity of satellite $K{\alpha }_3$ of copper on voltage with constant current. (2) Dependence of intensity of parent line $K{\alpha }_1$ of copper on voltage with constant current. (3) Ratio of intensities of satellite to parent. (4) Dependence of satellite intensity on current at constant voltage. The conclusions are (1) that the satellite is excited at a voltage differing from the excitation voltage of the parent line by too small an amount to be measured with certainty (less than 200 volts). (2) That the ratio of intensities of ${\alpha }_1$ to ${\alpha }_3$ as estimated from the areas of the spectral line structures is about 1:120. (3) That the intensity of the satellite $K{\alpha }_3$ of copper is strictly proportional to the current at constant voltage. These facts seem to invalidate the Wentzel-Druyvesteyn "spark line" hypothesis as an explanation of $K{\alpha }_3$ of copper. Richtmyer's "double jump" hypothesis remains tenable. In addition a doublet structure (separation of components about 2 X.U.) in $K{\alpha }_3$ of copper was observed (in accord with the doublet structure of this satellite in elements of lower atomic number).