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

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 L II and L III 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.