Abstract
The photoionization cross sections of helium have been measured from threshold down to 260 Å. At the spectral head the cross section is found to be 7.3×10−18 cm2. The experimental results are compared to available theoretical data. The oscillator strength for transitions into the ionization continuum have been estimated from threshold to 0.01 Å using the present and previously published data. A continuum f value of 1.54 is obtained. Applying the Thornas–Kuhn sum rule one therefore obtains the total oscillator strength for all discrete transitions as f = 0.46.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have