The author's previous calculations on dispersion and absorption in helium are extended to the continuous spectrum. By using ground state wave function due to Eckart, the intensity distribution ($\frac{\mathrm{df}}{\mathrm{dW}}$) within the continuum is calculated as a function of frequency. Table I and Fig. 1 give the results in detail. The total $f$-value of the continuum is found to be 1.55, which number when added to the $f$-values previously found for the principal series and double jumps gives a total $f$-value of 2.13 as against the mathematically required value 2.00. The series limit value of $\frac{\mathrm{df}}{\mathrm{dW}}$ obtained from the formula for the continuum is 1.05, agreeing with that found by approaching the series limit from the side of the discrete spectrum. The atomic absorption coefficient ${\mu }_a$ of helium for the $K\alpha$ line of carbon (44.6A) is calculated to be 3.24×${10}^{-20\mathrm{}}$ ${\mathrm{cm}}^{-1\mathrm{}}$, agreeing fairly well with the value 2.38×${10}^{-20\mathrm{}}$ ${\mathrm{cm}}^{-1\mathrm{}}$ found experimentally by Dershem and Schein. The results of the present paper are compared with those due to J. A. Wheeler, who used a Hylleraas function for the ground state of helium.

• Received 27 May 1933

DOI:https://doi.org/10.1103/PhysRev.44.524