Structure in the Hgi absorption spectrum from 20 to 120 Å associated with the excitation of the 4f and 5s subshells

Observation of a broad transmission maximum, centred at about 80 Å, in the continuous absorption cross-section of Hgi is reported. The experiments were performed with a windowless system, using the background radiation of the 2.5 GeV synchrotron of the University of Bonn. The existence of such a transmission maximum is discussed in relation to theoretical predictions. New features are also reported and identified as due to excitation from the 4f and 5s subshells.