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A method is presented for computer analysis of-v-ray spectra from semiconductor detector systems. We describe a mathematical formalism for the representation of photopeaks and the continua in their vicinity which is applicable to analysis of spectra measured under widely varying conditions. With this formalism the line shape is defined for each peak in the spectrum. The region of data about a single peak or mUltiple peaks is then fitted with the shape functions and a function representing the background continuum. The line-shape calculations and the fitting are performed by using a least-squares procedure with an iterative gradient minimization method with variable metric. For an automatic analysis an algorithm is developed to search the raw data for statistically significant peaks.

The /~-decay of 377ms 95Rb and 168ms 97Rb has been thoroughly investigated by means of 7-ray, conversion electron and /Ldelayed neutron spectroscopy. More than 97 % of the /~-decay to particle-bound states has been placed in level schemes of 95Sr and 97Sr. High-resolution neutron spectroscopic studies have allowed to extend the knowledge of the excitation spectra up to 9 MeV, respectively 10 MeV. The density of neutron-unbound levels in 95Sr and 97Sr has been derived from peak stripping analyses of the neutron spectra. Beta-strength functions (S~(E)) have been investigated in detail.They indicate that Gamow-Teller /~-decay of both precursors is dominated by nuclear structure. The discovered pronounced resonances and the variation in the shape of So(E ) are compared with predictions from the gross theory of/3-decay and shell model calculations in the random phase approximation (RPA).

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Several new high-spin states are observed in the prompt ␥-rays emitted from the neutron-rich, odd-Z 145,147 La fragments produced in the spontaneous fission of 252 Cf. Alternating parity bands are extended up to spins 41/2 and 43/2 in 145,147 La, respectively. A new band completes the evidence for two sets of parity doublets expected for octupole correlations. Eight B(E1)/B(E2) ratios ͑four new͒ between two bands in 145 La are all essentially constant and somewhat larger than similar ratios in 143,144 Ba, where stable octupole deformation and/or correlations are reported. The new ratios out of the 31/2 Ϫ levels in both nuclei show a sharp spike compared to other states, presumably from a strong reduction in E2 strengths in this backbending region. In 145 La, collective bands show competition and coexistence between symmetric and asymmetric shapes. Band crossings occur in both nuclei around បϷ0.26-0.30 MeV. Their backbends are associated with the alignment of two i 13/2 neutrons according to cranked shell model calculations. ͓S0556-2813͑99͒08402-2͔ PACS number͑s͒: 21.10. Re, 23.20.Lv, 27.60.ϩj, 25.85.Ca

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