G. Schatz

The odd-even staggering of the nuclear charge radii of Pb isotopes

Abstract Previous laser-spectroscopic studies of the hyperfine structure splittings and isotope shifts of the (6p 2 3 P 0 -6p7s 3 P 1 ; 283.3 nm) PbI resonance line have been extended to further radioactive Pb nuclides: 196, 197, 197m, 211, 214 Pb Using an improved theoretical result for the specific mass shift, we recalibrate the isotope shifts of the full series ( A = 196–214) of measured isotope shifts in terms of the nuclear parameter and determine the odd-even staggering parameters. The variation of the nuclear charge radii of the Pb nuclides exhibits distinct shell effects, and the odd-even staggering shows a conspicuous trend, being more pronounced for neutron-deficient Pb isotopes.

Investigation of delayed fission in 236U

Abstract The fission isomer of 236 U was produced by the reaction 235 U(d, p) 236 U using pulsed beam techniques. The half-life of the fission isomer was determined to be T 1 2 = 116 ± 7 ns . An isomeric to prompt fission ratio σ i / σ f = (1.24 ± 0.06) × 10 −5 was obtained. The measurements were performed with parallel-plate avalanche detectors which proved to be a high efficiency low background system.

The magnetic moment of the 92+ state in 85Rb, mesonic contributions in the z = 37 region and blocking of core polarization in the 1f52 proton shell

Abstract The g -factor of the 9 2 + state in 85 Rb ( E = 513 keV ; T 1 2 = 1015 ns ) was measured by the TDPAD and the SOPAD methods. The experimental value corrected for diamagnetism and the Knight shift is g = +1.369±0.010. The analysis of this g -factor together with the g -factors of the ground states in 85, 87 Rb shows that the effects usually attributed to mesonic exchange currents depend rather strongly on the corrections for core polarization. A comparison of g -factors of 9 + 2 states in As, Br and Rb isotopes shows a linear increase of the magnetic moments with increasing number of nucleons in the 1 f 5 2 proton shell as predicted by the M1 core polarization theory.