TRANSITIONS AND ENERGY-LEVELS IN AL-LIKE GE-XX, SE-XXII, SR-XXVI, Y-XXVII AND ZR-XXVIII

Transitions in Ge XX, Se XXII, Sr XXVI, Y XXVII and Zr XXVIII were identified in the extreme-ultraviolet spectra emitted from linear plasmas that were produced using line-focused laser beams. A grazing-incidence spectrograph viewed the plasma in the axial direction. Transitions between levels of the three odd configurations 3s(2)3p, 3p3 and 3s3p3d and the even 3s3p2 and 3s(2)3d were identified and the wavelengths in the range 90-220 angstrom were measured with an uncertainty of about 0.010 angstrom. Energy values, determined from the observed combinations were compared with values obtained from multi-configuration Dirac-Fock calculations. Fitted energy levels of 3p3 and 3s3p3d are also presented for elements between Cu and Rb.