The Emission Spectrum of D2 in the Extreme Ultraviolet

The emission spectrum of the ${\mathrm{D}}_{2}$ molecule has been photographed in the extreme ultraviolet region by use of a grazing incidence vacuum spectrograph with 2-meter grating In the $2p^{1}\ensuremath{\Sigma}\ensuremath{-}1s^{1}\ensuremath{\Sigma}$ system 37 bands have been analyzed. In the $2{p}^{1}\ensuremath{\Pi}\ensuremath{-}1s^{1}\ensuremath{\Sigma}$ system 29 bands were obtained. Constants of the three observed electronic states of the ${\mathrm{D}}_{2}$ molecule are given and the data are compared with that of the ${\mathrm{H}}_{2}$ molecule. Electronic shifts of 4 ${\mathrm{cm}}^{\ensuremath{-}1}$ and 23 ${\mathrm{cm}}^{\ensuremath{-}1}$ are observed for the $2p^{1}\ensuremath{\Sigma}\ensuremath{-}1s^{1}\ensuremath{\Sigma}$ and $2p^{1}\ensuremath{\Pi}\ensuremath{-}1s^{1}\ensuremath{\Sigma}$ systems, respectively.