1 Introduction

The intensities of emission lines arising from transitions in He-like ions are frequently used to determine the electron temperature and density of a plasma. The knowledge of the electron impact excitation of the He-like ions is required to analyze such emissions.

The Bragg Crystal Spectrometer on board the YOHKOH satellite (Culhane et al. [1991]) detects soft X-rays from SXV in the solar corona to provide information of the coronal plasma. Sampson et al. ([1983]) and Zhang & Sampson ([1987]) obtained cross sections for excitation of SXV by electron impact in the Coulomb-Born approximation with including the electron exchange and resonance effects approximately. Keenan et al. ([1987]) estimated the rate coefficients for SXV with an interpolation of the rate coefficients for other He-like ions. Nakazaki et al. ([1993]) calculated cross sections for the excitation of SXV in a close-coupling approach using the R-matrix method. In their calculation the nineteen lowest LS states were included and the complicated resonance structure in the energy range near the threshold was fully accounted for. They reported effective collision strengths "$\mit\Upsilon$'' for the transitions from the ground 1s^{2 1}S state to all LS states of 1s2$\ell$ ($\ell=0,1$) and 1s3$\ell$ ($\ell=0,1,2$) configurations. However, the analysis of the satellite data requires collision data between fine-structure levels.

In the present paper, the calculation with the R-matrix method (Nakazaki et al. [1993]) is repeated with parameters changed a little to improve the result. The calculation includes the same nineteen target terms as the previous calculation by Nakazaki et al. ([1993]). From the results, fine-structure cross sections are calculated with Saraph's ([1978]) program JAJOM, which transforms the LS coupled reactance matrices to those for intermediate coupling with the term-coupling coefficients. Finally effective collision strengths $\mit\Upsilon$ for the fine-structure levels are obtained from the corresponding cross sections and fitted to a polynomial function of $\log(T_{\rm e}/{\rm K})$. They are compared with the previous works mentioned above. Recently, to analyze emission spectra from laboratory plasmas and solar plasmas, Harra-Murnion et al. ([1996]) used the effective collision strengths of SXV which were calculated by Norrington et al. ([1998]) using the Dirac R-matrix method. The present results are compared with those of relativistic calculations to confirm the reliability of the former.