Regularity Along a Series in the Variation of the Action Cross Section with Energy Discrepancy in Impacts of the Second Kind

Abstract

The enhancement of the intensities of lines in the spark spectrum of lead when excited by impacts of the second kind with neon ions relative to their intensities in electron impact excitation was measured. When the values of the enhancements are plotted against the energy discrepancies of the spectral terms in which the lines originate, smooth characteristic curves can be drawn through the points belonging to the same spectral series. The curves for different series, while similar in form, exhibit marked differences in details. Measurements were made on terms of negative as well as on terms of positive energy discrepancy. Maxima appear in the curves on the side of positive energy discrepancy, i.e., on the side where the energy values of the terms are less than the ionization potential of neon. The form of the curves beyond the maxima indicates that they may be of the form $q=\frac{A}{{\sigma }^x}$ where the value of both $A$ and $x$ vary with the particular series. The terms of the $D$ series are most strongly enhanced. A calculation fixes the cross section for these collisions at approximately 15×${10}^{-11\mathrm{}}$ ${\mathrm{cm}}^2$.