ACCURATE OSCILLATOR-STRENGTHS FOR S-P TRANSITIONS IN THE HE ATOM

We obtain the accurate wavefunctions and energies for n1.3S and n1.3P states of He for n less-than-or-equal-to 5 by variational configuration calculation with B-spline basis functions. The accurate wavefunctions have been used to calculate oscillator strengths for the transitions mS-nP, m, n less-than-or-equal-to 5 in He. The results off values are accurate to within 0.01 per cent or better. The error estimate is based on the numerical convergence as the number of the angular partial waves of the employed wavefunctions is increased, and on the agreement between the results obtained using the dipole length and velocity formula. The accuracy of our results does not deteriorate with increasing principal quantum number. The accuracy of our results is better than the previous highly accurate calculated results of Schiff et al and Kono and Hattori. Our results also agree with some recent accurate experimental results. Therefore, our results can be regarded as being as reliable as those of Kono and Hattori at least, which are likely to be the most accurate theoretical results. Some radial expectation values are also calculated to give some indication of the accuracy of the wavefunctions.