Search results for "EXCITATION"
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Structure of theN=27isotones derived from theAr44(d,p)Ar45reaction
2008
The $^{44}\mathrm{Ar}$($d,p$)$^{45}\mathrm{Ar}$ neutron transfer reaction was performed at $10A$ MeV. Measured excitation energies, deduced angular momenta, and spectroscopic factors of the states populated in $^{45}\mathrm{Ar}$ are reported. A satisfactory description of these properties is achieved in the shell model framework using a new $\mathit{sdpf}$ interaction. The model analysis is extended to more exotic even-$Z$ nuclei down to ${}_{14}^{41}{\mathrm{Si}}_{27}$ to study how collectivity impacts the low-lying structure of $N=27$ neutron-rich nuclei.
Nuclear levels of 183W studied with and reactions
2011
Abstract The level structure of 183 W has been studied using gamma–gamma coincidences from thermal neutron capture in 182 W accompanied with the reaction ( d → , p ) . From these data and those of previous studies a total of 76 levels and about 490 connecting γ -transitions have been established for energies below 2.4 MeV. An analysis based on the standard distorted-wave Born approximation (DWBA) provides the lj -angular momentum transfers and spectroscopic factors for 36 levels up to 2.2 MeV excitation energy. A large number of particle transitions indicate an influence of strong mixing between particle and probably hole states. The extra exchange of phonons across the Fermi surface leads …
Medium-spin levels and the character of the 20.4 ns isomer in 145Gd
1982
Abstract Levels of the N = 81 nucleus 145Gd have been investigated by in-beam γ-ray and conversion electron spectroscopy with the 144Sm(3He, 2n) reaction. Fourteen new low- and medium-spin states between 1.0 and 2.4 MeV excitation, the known yrast levels up to spin 21 2 + , five other high-spin non-yrast states and a new 20.4 ns 13 2 isomer at 2200.2 keV in 145Gd have been observed. The isomer decays via a fast 927.3 keV E3 transition with B(E3) = 48 ± 7 W.u. Another weaker decay branch is a mixed, strongly hindered E1 + M2 + E3 transition to the v h −1 11 2 state. We propose an octupole v f 7 2 j −2 × 3 − main configuration for the isomer, analogous to the 997 keV 13 2 + isomer in 147Gd. T…
Transfer and neutron capture reactions toIr194as a test of Uν(6/12)⊗Uπ(6/4)supersymmetry
2008
The structure of $^{194}\mathrm{Ir}$ is investigated via ($n,\ensuremath{\gamma}),(n,{e}^{\ensuremath{-}}),(d,p)$, and ($\stackrel{\ensuremath{\rightarrow}}{d},\ensuremath{\alpha}$) spectroscopy. The use of different methods leads to an almost complete level scheme up to high excitation energies including \ensuremath{\gamma}-decay and spin-parity assignments. A reanalysis of the formerly published ($n,\ensuremath{\gamma}$) data was triggered by our new ($d,p$) and ($\stackrel{\ensuremath{\rightarrow}}{d},\ensuremath{\alpha}$) transfer reactions. The experimental level scheme is compared to predictions using extended supersymmetry. Herein, the classification of states was done according to q…
Interplay of quasiparticle and phonon excitations in 181Hf observed through (n,γ) and reactions
2002
Abstract Nuclear levels of 181 Hf were investigated in the range up to 3 MeV excitation energy by (n, γ ) and (d,p) reactions. Over 170 levels and about 390 γ -transitions were established most of them for the first time. 25 rotational bands were identified. Comparison of the results of the two reactions yields information on the fine structure in the fragmentation of Nilsson strength. The states below 2 MeV with the most complete spectroscopic information were interpreted in terms of the Quasiparticle Phonon Model (QPM). Excitation energies, electromagnetic transition rates, γ -branchings and spectroscopic factors are discussed in connection with their possible structure.
Mass and low-lying levels ofIn106,108from theCd106,108(p,nγ)reactions
1984
106In has been studied via the reaction 106Cd(p,nγ)106In in the energy range Ep=7-9 MeV. Inbeam γ-ray excitation functions, γ-γ coincidence measurements, and β+-delayed γ-ray excitation functions have been used to identify thirteen levels in 106In. From this new level scheme the energy separation of the high-spin ground state and the low-spin isomer has been determined to be 28.6±0.5 keV. The threshold energy of the strongest low-lying γ-ray transition yields a mass excess for 106In of -80601±15 keV. Spins for some states are suggested by comparing the excitation functions to Hauser-Feshbach calculations. In-beam γ-ray excitation functions for the 108Cd(p,nγ)108In reaction give a mass exces…
Giant resonances in unstable oxygen isotopes
1999
Abstract Electromagnetic and nuclear breakup of the neutron-rich Oxygen isotopes ranging from A = 17 to A = 22 is studied experimentally in reactions at energies around 600 MeV/u. The beams were produced in fragmentation reactions and separated by the GSI Fragment Separator FRS. By measuring the four-momenta of all decay products after inelastic scattering and neutron decay of the projectile, the excitation energy is determined. From the differential cross sections dσ dE ∗ for electromagnetic excitation, the E1-strength distributions can be deduced. For 18,20,22O, low-lying dipole strength is observed, exhausting about 5% of the Thomas Reiche Kuhn sumrule for energies up to 5 MeV above the …
Neutron Excitations Across the N=50 Shell Gap in 102In
2002
The structure of In-102 has been investigated by in-beam gamma-spectroscopic methods. Knowledge on the excited states of this nucleus has significantly been extended. Three cascades of transitions were observed to exceed the spin-energy domain spanned by the pig(9/2)(-1)v(d(5/2),g(7/2))(3) configurations. The new high spin states at similar to 4 MeV excitation energy could be assigned to the pig(9/2)(-1)v(d(5/2), g(7/2))(2)h (11/2) configuration, while at least those at 4.733, 5.192 and 5.853 MeV most likely arise from the vg(9/2) --> vd(5/2), g(7/2) one-particle-one-hole excitation across the N = 50 shell closure.
Nuclear structure of 157Gd
2003
Abstract The energy levels of 157 Gd have been investigated using the (n, γ ) and (n, n′ γ ) reactions. As a result of the analysis of the γ -ray spectra from 16 isolated neutron resonances, a level scheme with a complete set of levels with spins J =1/2, 3/2 has been established up to 1.86 MeV excitation energy. A part of the level scheme is interpreted in more detail on the basis of Coriolis and Δ N =2 coupled Nilsson configurations. Slightly different sets of shape parameters are deduced for negative- and positive-parity levels. A large excess of unassigned 1/2 and 3/2 levels evidently requires an explanation in terms of inclusion of new additional degrees of freedom.
Energy dependence of the $^{28}$Si($^{32}$S,$^{36}$Ar)$^{24}$Mg reaction between 90 and 103 MeV incident energy
1986
Abstract Angular distributions for the 28 Si( 32 S, 36 Ar) 24 Mg reaction have been measured from 90 to 103 MeV of incident lab energy, in steps of 0.5 MeV. The ground state, the 2 1 + level in each nucleus and the mutual excitation of both 2 1 + states have been resolved. The data have been analysed in the frame of finite range DWBA calculations. The deduced relative spectroscopic factors show good agreement with those predicted by the model of Chung and Wildenthal but are smaller than those deduced in other experiments.