The Mean Life for the Mercury Spark Spectrum

Abstract

By using the method previously described by the writer for measuring the average life of excited ions, a mean life of 9×${10}^{-7\mathrm{}}$ and 8×${10}^{-7\mathrm{}}$ seconds was found for the 3114 and 2572 lines, respectively, of Hg IV, 6×${10}^{-7\mathrm{}}$, 4×${10}^{-7\mathrm{}}$ and 4×${10}^{-7\mathrm{}}$ seconds for the 3090, 3312 and 4797 lines respectively of Hg III. The prominent lines of Hg II are estimated to have a mean life of the order of ${10}^{-8\mathrm{}}$ seconds. These results indicate that the greater the charge of the ion producing the line the longer the mean life. The formula derived for determining the mean life is discussed and experimental results are given which agree quite satisfactorily with the theory developed for measuring the mean life. Intensity-current relations of the spark lines show that they are produced as the result of single electron collisions, which substantiates the assumptions made in the above theory. It is pointed out that lines due to electrons jumping from the same energy level should have the same mean life regardless of the level to which the electrons may jump. The above lines have not been classified so a correlation between the electron transitions and mean lives cannot at present be made.