| Popis: |
Detailed measurements have been made of the absorption cross section of Cs 2 in the visible ( C « X 1 ∑ + g , and other higher systems) and of K 2 in the red ( B 1 ∏ u « X 1 ∑ + g ). The C s 2 values, extending from 4700 to 6700 A, vary from about 0·01 to 1·2 A 2 . A representative value in the more prominent blue and red regions of the smeared-out spectrum is several tenths A 2 . The K 2 cross section varies from 5 to 25 A 2 for averaged data from 6200 to 6750 A, with the peak of the clearly-visible band structure reaching 35 A 2 at the (2, 0) band head. The cross sections were measured from absorption spectra taken as a function of optical depth for varying amounts of several inert broadening gases. Maximum effective cell-length and temperature uncertainties lead to maximum estimated errors of roughly +25 to -35 per cent. |
