Marine climate and fisheries scenario of Maharashtra Climcard-4

Marine climate and fisheries scenario of Maharashtra Climcard-

Decay modes of 250No

The Fragment Mass Analyzer at the ATLAS facility has been used to unambiguously identify the mass number associated with different decay modes of the nobelium isotopes produced via 204Pb(48Ca,xn)(252-x)No reactions. Isotopically pure (>99.7%) 204Pb targets were used to reduce background from more favored reactions on heavier lead isotopes. Two spontaneous fission half-lives (t_1/2 = 3.7+1.1-0.8 us and 43+22-15 us) were deduced from a total of 158 fission events. Both decays originate from 250No rather than from neighboring isotopes as previously suggested. The longer activity most likely corresponds to a K-isomer in this nucleus. No conclusive evidence for an alpha branch was observed, resulting in upper limits of 2.1% for the shorter lifetime and 3.4% for the longer activity.Comment: RevTex4, 10 pages, 5 figures, submitted to PR

Multi-quasiparticle structures up to spin ~44ħ in the odd-odd nucleus Ta168

High-spin states in the odd-odd nucleus Ta168 have been populated in the Sn120(V51,3n) reaction. Two multi-quasiparticle structures have been extended significantly from spin ~20 to above 40. As a result, the first rotational alignment has been fully delineated and a second band crossing has been observed for the first time in this nucleus. Configurations for these strongly coupled rotational bands are proposed based on signature splitting, B(M1)/B(E2) ratio information, and observed rotation-alignment behavior. Properties of the observed bands in Ta168 are compared to related structures in the neighboring odd-Z, odd-N, and odd-odd nuclei and are discussed within the framework of the cranked shell model

Decay spectroscopy of two-quasiparticle K isomers in Cm 246,248 via inelastic and transfer reactions

The decay of K isomers in Cm (Z = 96) isotopes has been studied using inelastic and transfer reactions. The half-life of a previously identified 2-quasiparticle (qp) Kπ=8- isomer in Cm246 has been measured. A new 2-qp isomer is observed in Cm248, its half-life measured and its decay scheme established. The reduced K hindrances extracted for the decay transitions from the isomers in Cm246,248 indicate K to be a robust quantum number and validate axial symmetry in these nuclei. The excitation energies of the 2-qp isomers in Cm246 (N = 150) and Cm248 (N = 152) support the persistence of a deformed subshell gap at N = 152 in the Z≈100 region down to Z = 96 nuclei

Band crossings in Ta166

High-spin states in the odd-odd nucleus Ta166 are investigated through the 5n channel of the V51+Sn120 reaction. Four new bands are observed and linked into the previous level scheme. Configurations for the bands are proposed, based on measured alignments and B(M1)/B(E2) transition strength ratios

Rotational structures and the wobbling mode in Ta167

Excited states in the neutron-deficient nucleus Ta167 were studied through the Sn120(V51,4n) reaction. Twelve rotational bands have been observed and the relative excitation energy of each sequence is now known owing to the multiple interband connections. Several quasineutron alignments were observed that aided in the quasiparticle assignments of these bands. The resulting interpretation is in line with observations in neighboring nuclei. Trends in the wobbling phonon energy seen in Lu161,163,165,167 and Ta167 are also discussed and particle-rotor model calculations (assuming constant moments of inertia) are found to be inconsistent with the experimental data

Population and decay of a Kπ=8- two-quasineutron isomer in Pu 244

The decay of a Kπ=8- isomer in Pu244 and the collective band structures populating the isomer were studied using deep inelastic excitations with Ti47 and Pb208 beams, respectively. Precise measurements of M1/E2 branching ratios in the band confirm a 9/2-[734]ν - 7/2+[624]ν configuration assignment for the isomer, validating the systematics of Kπ=8-, two-quasineutron isomers observed in even-Z, N=150 isotones. These isomers around the deformed shell gap at N=152 provide critical benchmarks for theoretical predictions of single-particle energies in this gateway region to superheavy nuclei

Transverse wobbling in Pr 135

A pair of transverse wobbling bands is observed in the nucleus Pr135. The wobbling is characterized by ΔI=1, E2 transitions between the bands, and a decrease in the wobbling energy confirms its transverse nature. Additionally, a transition from transverse wobbling to a three-quasiparticle band comprised of strong magnetic dipole transitions is observed. These observations conform well to results from calculations with the tilted axis cranking model and the quasiparticle rotor model

N=151Pu, Cm and Cf nuclei under rotational stress: Role of higher-order deformations

Fast-rotating N=151 isotones 245Pu, 247Cm and 249Cf have been studied through inelastic excitation and transfer reactions with radioactive targets. While all have a ground-state band built on a νj15/2[734]9/2- Nilsson configuration, new excited bands have also been observed in each isotone. These odd-N excited bands allow a comparison of the alignment behavior for two different configurations, where the νj15/2 alignment is either blocked or allowed. The effect of higher order deformations is explored through cranking calculations, which help clarify the elusive nature of νj15/2 alignments