On the existence of `white line' for Ta, W and Re

Abstract
The L-absorption spectra of Ta, W and Re have been recorded photographically using a newly constructed one meter curved crystal spectrograph of transmission type. A pronounced absorption maximum usually called a `white line' has been detected both at the LII and LIII absorption discontinuities of these elements. An attempt has been made to explain the appearance of white line in the light of available theoretically determined density of states.