A NEW ENERGY-LEVEL OF THE NEUTRAL TANTALUM ATOM

Investigating the hyperfine structure (hfs) of the not yet classified line lambda = 4160.99 Angstrom we suceeded in the determination of the electronic angular momenta of the combining levels and in the identif ication of the lower level using the hfs constants of all known levels as a fingerprint card-index. In this way the lower level turned out t o be the a(2)G(9/2) level, which has even parity. Using the energy of this level and the wavenumber of the transition it was possible to det ermine the energy of the (odd parity) upper level to 34716.23 +/- 0.02 cm(-1). The total angular momentum quantum number amounts to J = 11/2 . Additionally, it was possible to identify the line lambda = 3436.00 Angstrom as a further combination with this new level.