UBC Theses and Dissertations
Measurements of the Stark widths of N II and N III spectral lines at variable electron densities Purcell, Stephen T.
The Stark widths of seventeen N II and ten N III spectral lines, emitted by plasmas with free electron densities of .9 ± .1 x 10¹⁷, 2.2 ± .3 x 10¹⁷ and 2.9 ± .4- x 10¹⁷ cm⁻¹³, were measured. Nine of the N II linewidths and four of the N III linewidths have not been previously measured. The plasma source was a wall stabilized discharge filled with 50% helium and 50% nitrogen. The different electron densities were produced by varying the filling pressure and charging voltage. The electron temperature was determined from the intensity ratio of several N II to N III lines. The electron densities were estimated by measuring the Stark widths of He I 5876 and 6678. The nitrogen lines were measured at different plasma conditions to check linear scaling of Stark width vs electron density on the same device. However, the large errors in both the Stark widths and the electron density measurements, about half of which came from appreciable optical depths, made it difficult to check the scaling even over the limited range of this experiment.
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