5 Discussion

The theoretical Stark FWHM dependence on the electron temperature together with the values of the other authors and our experimental results at the electron density of N = 110²³ $\rm m^{-3}$ are presented graphically in Fig. 5, assuming the domination of the electron impact mechanism to the line broadening.

  

Figure 5: Theoretical Stark FWHM (w) dependence on the electron temperature scaled to the electron density of a 11023 $\rm m^{-3}$ for the 463.054 nm NII spectral line. $\bullet$, our experimental results and those of the other authors: $\ifmmode\hbox{\rlap{$\sqcap$}$\sqcup$}\else{\unskip\nobreak\hfil \penalty50\hsk... ...box{\rlap{$\sqcap$}$\sqcup$} \parfillskip=0pt\finalhyphendemerits=0\endgraf}\fi$, Berg et al. (1967); $\circ$, Jalufka & Craig (1970); $\nabla$, Konjevic et al. (1970); $\blacksquare$, Popovic et al. (1975); $\triangle$, Purcell & Barnard (1984); $\oplus$, Puric et al. (1987); $\otimes$, Perez et al. (1997); +, Milosavljevc & Djenize (1998). Theory: --, our calculated impact widths on the basis of the modified semiempirical approximation (SEM). The error bars include the uncertainties of the width and electron density measurements

The agreement between the existing experimental Stark FWHM ($w_{\rm m}$), including our new data, and calculated ($w_{\rm th}$) data on the basis of the modified semiempirical approximation is satisfactory, especially in the electron temperature range between 23000 K and 38000 K. At lower electron temperatures the existing experimental $w_{\rm m}$ data lies under theoretical $w_{\rm th}$ values. The situation is the same at higher electron temperatures. Ratios $w_{\rm m}$/$w_{\rm th}$ are presented in Table 3. It should be pointed out that the scatter of the ratio $w_{\rm m}$/$w_{\rm th}$ around one is acceptable taking into the experimental uncertainties and the reliability of the theoretical approximation.

 

Table 3: Ratio of the measured to the calculated Stark FWHM at N = 110²³ $\rm m^{-3}$ electron density for various electron temperatures obtained in various experiments. * denote averaged electron temperaure between 5000 K and 8000 K from Perez et al. (1997)