Search results for "hell"
showing 10 items of 1035 documents
Coexisting structures in 115Sn and 116Sn
1998
Abstract Excited states up to I ≈ 20 in 115 Sn and 116 Sn, populated via the ( 18 O, αxn) reactions, have been studied using the DORIS Ge detector array in conjunction with charged particle detectors. In both nuclei, spherical as well as regular, deformed level structures were found. The spherical states are interpreted to arise from pure neutron configurations, while the deformed, intruder bands obviously involve proton 2p-2h excitations across the Z = 50 shell gap.
AK=3two-quasiparticle isomer in98Sr
2002
The decay of on-line mass-separated ${}^{98}\mathrm{Rb}$ to ${}^{98}\mathrm{Sr}$ is studied by $\ensuremath{\gamma}$ spectroscopy. The revised decay scheme adds further evidence of the coexistence of very different shapes in ${}^{98}\mathrm{Sr}.$ A set of levels is proposed to originate from particle-hole pair excitations across the $Z=40$ spherical gap in analogy with ${}^{96}\mathrm{Sr}.$ A deformed $K=3$ band with probable even parity is built on a 7.1-ns isomer at 1838 keV. It is interpreted as a two-quasineutron excitation in accordance with a quantum Monte Carlo pairing calculation based on a deformed shell model. Configurations of the calculated lowest-lying two-quasiparticle levels …
Cranked Relativistic Hartree-Bogoliubov Theory: probing the gateway to superheavy nuclei
2003
The cranked relativistic Hartree+Bogoliubov theory has been applied for a systematic study of the nuclei around 254No, the heaviest elements for which detailed spectroscopic data are available. The deformation, rotational response, pairing correlations, quasi-particle and other properties of these nuclei have been studied with different parametrizations for the effective mean-field Lagrangian. Pairing correlations are taken into account by a finite range two-body force of Gogny type. While the deformation properties are well reproduced, the calculations reveal some deficiencies of the effective forces both in the particle-hole and particle-particle channels. For the first time, the quasi-pa…
β-decay half-life ofV50calculated by the shell model
2014
In this work we survey the detectability of the ${\ensuremath{\beta}}^{\ensuremath{-}}$ channel of ${}_{23}^{50}\mathrm{V}$ leading to the first excited ${2}^{+}$ state in ${}_{24}^{50}\mathrm{Cr}$. The electron-capture (EC) half-life corresponding to the transition of ${}_{23}^{50}V$ to the first excited ${2}^{+}$ state in ${}_{22}^{50}\mathrm{Ti}$ had been measured earlier. Both of the mentioned transitions are 4th-forbidden non-unique. We have performed calculations of all the involved wave functions by using the nuclear shell model with the GXPF1A interaction in the full f-p shell. The computed half-life of the EC branch is in good agreement with the measured one. The predicted half-lif…
The Role of Fission in the r-process
2007
We have developed a full set of fission rates that include spontaneous fission, neutron-induced fission, beta-delayed fission and, neutrino-induced fission, that are supplemented with realistic distributions of fission yields. Using this new input data we have carried out r-process calculations assuming adiabatic expansions that mimic the conditions achieved in the supernova neutrino driven wind. We have explored the sensitivity of the final abundances to different mass models. The resulting abundance distribution turns out to be very sensitive to the strength of the N = 82 shell gap far from stability. Mass models with a strong shell gap converge to an r-process distribution that is indepe…
High-resolution study of Gamow-Teller transitions in the47Ti(3He,t)47V reaction
2013
In this work we have studied ${T}_{z}=+2\ensuremath{\rightarrow}+1$, Gamow-Teller (GT) transitions in the $^{48}\mathrm{Ti}(^{3}\mathrm{He},t)^{48}\mathrm{V}$ charge-exchange reaction at 140 MeV/nucleon and ${0}^{\ensuremath{\circ}}$ at the Research Center for Nuclear Physics, Osaka. From the high-resolution facility, consisting of a high-dispersion beamline and the Grand Raiden spectrometer, the spectrum had an energy resolution of 21 keV, among the best achieved. Individual GT transitions were observed and GT strength was derived for each state populated up to an excitation energy of 12 MeV. The total sum of the $B$(GT) strength observed in discrete states was 4.0, which is 33% of the sum…
Beta decay of $^{56}$Cu
2001
AbstractThe proton-rich isotope 56 Cu was produced at the GSI On-Line Mass Separator by means ofthe 28 Si( 32 S, p3n) fusion–evaporation reaction. Its β -decay properties were studied by detecting β -delayed γ rays and protons. A half-life of 93± 3 ms was determined for 56 Cu. Compared to theprevious work, six new γ rays and three new levels were assigned to the daughter nucleus 56 Ni. Themeasured Gamow–Teller strength values for five 56 Ni levels are compared toshell-model predictions. 2001 Elsevier Science B.V. All rights reserved. PACS: 21.10.-k; 23.40.-s; 21.60.Cs; 27.40.+zKeywords: R ADIOACTIVITY 56 Cu ( β + ) [from 28 Si( 32 S, p3n)]; Measured E γ , I ; Deduced β -intensity and β -st…
Sn108studied with intermediate-energy Coulomb excitation
2005
The unstable neutron-deficient Sn-108 isotope has been studied in inverse kinematics by intermediate-energy Coulomb excitation using the RISING/FRS experimental setup at GSI. This is the highest Z nucleus studied so far with this method. Its reduced transition probability B (E2;0(g.s.)(+)-> 2(1)(+)) has been measured for the first time. The extracted B(E2) value of 0.230(57)e(2) b(2) has been determined relative to the known value in the stable Sn-112 isotope. The result is discussed in the framework of recent large-scale shell model calculations performed with realistic effective interactions. The roles of particle-hole excitations of the Sn-100 core and of the Z=50 shell gap for the E2 po…
Lifetime measurements in neutron-rich63,65Co isotopes using the AGATA demonstrator
2013
Lifetimes of the low-lying (11/2-) states in 63,65Co have been measured employing the recoil distance doppler shift method (RDDS) with the AGATA γ-ray array and the PRISMA mass spectrometer. These nuclei were populated via a multinucleon transfer reaction by bombarding a 238U target with a beam of 64Ni. The experimental B(E2) reduced transition probabilities for 63,65Co are well reproduced by large-scale shell-model calculations that predict a constant trend of the B(E2) values up to the N=40 67Co isotope
Maximum spin aligned states in 98 47Ag51
1998
New excited states have been observed in the neutron deficient isotope Ag-98 following the Ni-58+Cr-50-->Te-108* heavy-ion reaction. One of these states may be interpreted as a maximum spin aligned state of the pi g(9/2)(-3) nu vg(7/2) configuration. Other possible interpretations within the nuclear shell model are discussed as well.