Study of muonic atoms in the A = 100 - 140 mass regions (nuclear charge radii, isotope and isotone shifts) and in the Sm-Gd and W-Os-Pt transition regions (electric monopole and quadrupole moments). Progress report No. 6, October 16, 1980-October 15, 1981

During the reporting period the analysis of the over 100 muonic spectra of practically all stable isotopes of Ru, Pd, Cd, Sn, Te and Ba has progressed satisfactorily and systematic trends of the ΔN = 2 isotope and of the ΔZ = 2 isotone shifts have been established. The analysis of the muonic x-ray spectra of the Gd-isotopes 154155156157158160Gd has been completed. A paper describing precise measurements of the ground-state quadrupole moments of 155Gd and 157Gd has been published. The discrepancies in the energy splitting of the 3d and 2p levels of muonic 208Pb was partly solved by a precise re-measurement of the d/sub 5/3/ - d/sub 3/2/ splitting energy. Uncertainties in the nuclear polarization corrections cannot account for the discrepancies that still exist in the 2p/sub 3/2/ - 2p/sub 1/2/ splitting energy. A theoretical attempt to explain the observed isotope shifts in Ca nuclei was qualitatively successful. A refinement of the model, however, is needed to provide a quantitative explanation of the experimental results