共查询到20条相似文献,搜索用时 31 毫秒
1.
J. Deslauriers S. C. Gujrathi S. K. Mark 《Zeitschrift für Physik A Hadrons and Nuclei》1977,283(1):33-42
The nuclide141Eu is identified to have two beta decaying isomers,141g Eu and141m Eu, whose decay half-lives are measured to be 40.0±0.7 s and 3.3±0.3s, respectively. Their decay properties are studied by means of beta and gamma spectroscopy techniques. The states withJ π assignments in141Sm thus deduced are compared with those of the other odd-A, N=79 isotones. The total decay energy of141g Eu is measured to be 6.03±0.10 MeV, which is compared with the predictions of several mass formulae and with the decay energy systematics of theN=78 isotones. The141g Eu and141m Eu are deduced to haveJ π =5/2+ and 11/2?, respectively. A 96.4 keV isomeric transition between them is found to be anE3 transition with aB(E3)=1.6±0.4e 2fm6. The structure of141Eu is compared with that of the otherN = 78 isotones. 相似文献
2.
E. M. Alakshin R. R. Gazizulin A. V. Klochkov S. L. Korableva T. R. Safin K. R. Safiullin M. S. Tagirov 《Optics and Spectroscopy》2014,116(5):721-723
The influence of microwave irradiation on the recovery of nanocrystalline PrF3 powders has been experimentally analyzed by nuclear magnetic resonance (NMR) at T = 1.5 K. It is established that the relaxation times of 141Pr and 19F nuclei rise significantly with an increase in the hydrothermal-treatment time, whereas the 141Pr NMR spectra narrow, which indicates a decrease in the number of defects in the lattices of nanosamples. 相似文献
3.
H. H. Hansen 《Zeitschrift für Physik A Hadrons and Nuclei》1979,291(1):43-47
Accurate experimental internal conversion data have been used to study the effect of nuclear penetration in the case of thel-forbidden transitions in139La (165.8 keV),141Pr (145.4 keV) and203Tl (279.2 keV). The nuclear penetration parameterλ and theE2/M 1 mixing ratioδ 2 have been deduced by graphical analysis. Following results were obtained:λ=2.8±1.3,δ 2 =(8.4 ?8.4 +14.0 )·10?4 for139La,λ=1.2±0.6,δ 2=(4.8±0.5)·10?3 for141Pr, andλ=6.4±1.1,δ 2=1.36±0.12 for203Tl. 相似文献
4.
《Nuclear Physics A》1987,472(2):295-317
The high spin states of 162Yb and 164Hf have been studied using 122Sn(44Ca, 4n) and 120Sn(48Sn(48Ti, 4n) reactions respectively. The resulting new level schemes for 162Yb and 164Hf are presented and compared with existing data for 160Er. The systematic behaviour of these three N = 92 isotones at large angular momentum yields information both on modifications of the single-neutron spectrum of states resulting from the polarisation of the nuclear field and on the single-proton spectrum of states. 相似文献
5.
A. G. Belov Yu. P. Gangrsky L. M. Melnikova V. Yu. Ponomarev N. Tsoneva Ch. Stoyanov A. Tonchev N. Balabanov 《Physics of Atomic Nuclei》2001,64(11):1901-1908
Isomeric ratios were measured for N=81 isotones (135Xe, 137Ba, 139Ce, 141Nd, 143Sm). In the experiment reported here, μ ν ≤3±10? J π=11/2? isomers were excited in (n, γ) and (γ, n) reactions and in the β + decay of 139Pr and 141Pm. In order to determine the reaction yields, use was made of the activation method involving measurement of the gamma-ray spectra of reaction products. It is found that, in the same reactions, isomeric ratios are different for isotones characterized by different atomic numbers Z. Isomeric ratios were calculated with the spectra of low-lying levels and radiative-transition probabilities established on the basis of the quasiparticle-phonon model. Good agreement between the experimental and calculated values of isomeric ratios is obtained for all isotopes invesigated here. The dependence of isomeric ratios on the atomic number Z of a nucleus is explained by the difference of reaction energies, which leads to different probabilities of excitation of activation levels through which the isomers being considered are populated. 相似文献
6.
S. Kawarazaki N. Kunitomi Y. Morii H. Suzuki R.M. Moon R.M. Nicklow 《Solid State Communications》1984,49(12):1147-1151
At several reciprocal lattice positions of PrSn3, we observed Bragg scattering of neutrons which is purely due to the nuclear spin polarization of 141Pr, and could measure the temperature dependence of the polarization between 10 mK and 4.2 K. From the perfectly polarized state of the nuclear spins, the difference between the spin-dependent nuclear scattering lengths b+ and b- has been determined to be b+ - b- = -0.110 ± 0.006 × 10-12 cm, which is significantly larger in magnitude than the previously reported value. An additional electronic polarization which is linearly proportional to the nuclear spin polarization has also been observed. 相似文献
7.
B. Bleaney 《Applied magnetic resonance》1993,5(1):63-67
PrF3 is an enhanced nuclear paramagnet for which the resonance parameters have been determined both by acoustic resonance (Al’tshuleret al., 1979 [1]) and by conventional nuclear magnetic resonance (Nielsen, 1983 [2]). In this paper, the temperature at which the nuclei of the single stable isotope141Pr,I=5/2, enter an ordered state is estimated to beca. 0.1 mK, smaller than the overall nuclear electric quadrupole splitting 6P/h=1.2 mK. Possible arrangements of the nuclear moments in the ordered state are discussed, together with the requirements for a neutron diffraction measurement. 相似文献
8.
E. M. Alakshin A. S. Aleksandrov A. V. Egorov A. V. Klochkov S. L. Korableva M. S. Tagirov 《JETP Letters》2011,94(3):240-242
Nuclear pseudoquadrupole resonance of 141Pr in Van Vleck paramagnet PrF3 has been observed in singlecrystal and micro- and nanopowder samples at a temperature of 4.2 K. The spectra of nuclear pseudoquadrupole
resonance of 141Pr, as well as the spin-spin and spin-lattice relaxation parameters, have been obtained. The parameters of the nuclear spin
Hamiltonian have been determined. It has been found that the parameters of the crystal electric field in nanocrystals differ
strongly from those in microcrystals. 相似文献
9.
G. G. Kennedy S. C. Gujrathi S. K. Mark 《Zeitschrift für Physik A Hadrons and Nuclei》1975,274(3):233-239
The level structure of theN=80,140Nd has been investigated through the beta decay of140m Pm and140g Pm, whose decay half-lives were measured to be 5.95±0.05 min and 9.1±0.5 sec, respectively. Decay schemes for the two isomers have been constructed fromγ-ray measurements. With the help of the beta decayft values and internal conversion electron measurements, spins and parities were deduced for levels in140Nd. Among the levels a 7? state at 2222.0 keV and a 5? state at 2273.3 keV are identified as two-neutron quasiparticle states. The (ie233-01) for140m Pm and140g Pm have been deduced as 7? and 1+, respectively. From beta end-point measurements, the decay energies of the two isomers have been determined asQ EC=6.48±0.07 MeV140m (Pm) andQ EC=6.08±0.10 MeV (140gPm). The results are discussed in the light of nuclear systematics of theN=79 and 80 isotones. 相似文献
10.
Strutinsky-type cranking calculations with inclusion of pairing correlations have been performed for the rare-earth nuclei 156, 158, 164Dy and 164Er. The pairing effects contribute significantly and with their inclusion the calculated yrast spectra agree very well with experiments. Using Hartree-Fock-Bogouliubov cranking wave functions we have calculated the magnetic moments and quadrupole moments for states up to spin . The quadrupole moments are found to be constant over the whole spin range. The gyromagnetic factors g(I) show a strong I-dependence for 156, l58Dy, a weaker one for 164Er and none for 164Dy. The sensitivity of this spin dependence on the single-particle occupation and the pairing degrees of freedom is studied. It is found that the spin variation of the gyrofactors is a rotational alignment effect. 相似文献
11.
The proton-hole character of states in159Ho has been studied using the162, 164Er(p, α)159, 161Ho reactions with 17 MeV protons. The shapes of angular distributions measured for both nuclei were compared, with good agreement in most cases, to tritoncluster-transfer DWBA calculations. The deviations obtained and the experimental normalization factors deduced for the164Er(p, α)161Ho reaction by comparisons to (t, α) cross sections indicate a need for a revised treatment of the mechanism of the (p, α) reaction on deformed nuclei. By comparisons to the well-known states in161Ho, nuclear structure factors were obtained for many levels in159Ho. The Nilsson assignments for the 3/2+[411], 5/2?[532] and 5/2+[413] bands were confirmed and the lowest rotational members of these bands were established. The anomalous strengths of the strongly mixed positive parity states in159, 161, 163Ho are discussed in the frame-work of the Nilsson model with the pairing and effective Coriolis strengths included. The Coriolis strengths giving best fits to excitation energies also improve the agreement of theory with the experimental nuclear structure factors. Rotational spacings of the 5/2+[413] and especially those of the 5/2?[532] bands in159, 161, 163Ho show mixmg effects unexplainable by the present calculations. 相似文献
12.
A 3He-20Ne and a 3He-22Ne 1.52 m laser were frequency stabilized to the Lamb-dip of their respective gain curve and provided a resettability of 2 MHz. Using these lasers, absolute frequencies for the 20Ne and 22Ne laser transitions were measured by interferometric frequency comparison with an I2-stabilized He-Ne laser at 0.633 m. A least-square analysis which accounts for the linear frequency dependence of the laser gas pressure yielded two parameters which can reproduce the measured frequencies within an accuracy of ±1.0·10–8 at 1.52 m. 相似文献
13.
《Nuclear Physics A》1988,485(1):136-160
A decay scheme for the 130±20 ns high-spin isomer in 182Os has been established. The excitation energy of the isomer is 7049±1 keV and it has Iπ = 25(+). A 2.4% decay directly to the yrast 24+ level at 5988 keV is observed. In 184Os a 20±5 ns isomer is observed at 2366±1 keV excitation energy with Iπ = 10+. Again, direct transitions into the yrast 8+ and 10+ levels are observed. Contrary to previous speculations, there is no compelling evidence for stable triaxial shapes in the structure of the levels through which the isomers decay. The abnormally short half-lives observed, as well as the unusual decay patterns, are best understood in terms of a γ-soft nuclear potential. Motion in the γ-direction allows the isomer to decay via barrier penetration from an axially symmetric prolate shape with the angular momentum along the nuclear symmetry axis (deformation aligned state) via oblate shapes to another prolate shape with the angular momentum perpendicular to the nuclear symmetry axis (rotation-aligned state). 相似文献
14.
J. Jastrzȩbski R. Kossakowski J. Łukasiak M. Moszyński Z. Preibisz S. André J. Genevey A. Gizon J. Gizon 《Physics letters. [Part B]》1980,97(1):50-54
The search for and study of high spin isomers produced by 12C, 14N and 16O induced reactions on targets close to N = 82 has been performed. The observed isomers were identified unambiguously by a detailed study of the excitation functions, delayed gamma-ray multiplicity and multiparametric gamma-gamma coincidences. The isomers with the highest spin above the ground state were observed in 152Er and 151Ho nuclei. 相似文献
15.
《Nuclear Physics A》1986,449(3):537-578
High-spin states in 164Yb have been populated in the 152Sm(16O, 4n) and 150Sm(18O, 4n) reactions. From studies of γγ coincidences, γ-ray angular distributions and conversion electron measurements the level scheme has been constructed. The g-band and the S-band have been established to spin and parity 22+ and 26+', respectively, and the rotational sequences (π, α) = (−, 1)1, (−, 0)1 and (−, 0)2 to 23−, 24− and 18−, respectively. Constructed two-quasineutron configurations and cranked shell model calculations are compared with the experimental results. Residual interactions between quasiparticles are extracted from data. The side-bands in 162, 164Er and 164, 166Yb are discussed, putting a special emphasis on the octupole bands and their interaction with the two-quasiparticle bands. Crossing frequencies and the gain in alignment are summarized for the Yb isotopes and the main features are discussed. 相似文献
16.
A. Charvet R. Chéry Do Huu Phuoc R. Duffait 《Zeitschrift für Physik A Hadrons and Nuclei》1974,267(5):355-358
The decay of 3.0 min143Eu has been investigated by means of a Ge(Li) detector. TheΒ + spectrum obtained with a Si(Li) spectrometer leads to aQ-value of 5100±50 keV. For the first time a decay scheme including levels situated at 107.5, 755.0, 1107.9, 1537.5 and 1912.8 keV has been established. The data are compared to those obtained for the neighbouringN=81141Nd nucleus. Besides, new experimental measurements indicate that the 1345.4 keV level in141Nd has not the odd-parity and would be 5/2+, 7/2+. Hence, the 7/2? state is situated at 1967.4 keV. Those data are in reasonable agreement with intermediate coupling calculations. 相似文献
17.
R. Broda M. Ogawa S. Lunardi M. R. Maier P. J. Daly P. Kleinheinz 《Zeitschrift für Physik A Hadrons and Nuclei》1978,285(4):423-424
High spin isomers in 147 Gd and 146 Gd have been produced in (α, xn)reactions, and their half-lives, excitation energies and maximum spins have been determined. It is proposed that these isomers are identical with those recently observed in bombardments with 50 Ti and 40 Ar projectiles. 相似文献
18.
K.G. Bernhardt H. Bohn K.A. Eberhard R. Sielemann R. Vandenbosch M.P. Webb 《Nuclear Physics A》1981,365(1):157-172
Excitation functions for α-emission leading to the ground and first excited states of 26Mg and 8Be emission leading to the ground and first and second excited states of 22Ne have been measured at several forward angles for Ec.m. = 15 to 22.4 MeV. There is little evidence for correlated structure. The angular distribution at 16.5 MeV for the α + 26Mg(g.s.) channel is rather structureless while that for the 8Be+22Ne(g.s.) channel appears to be dominated by a J = 13 contribution. Statistical model calculations indicate that much of the yield for both the α and 8Be exit channel is compound nuclear in origin, with some indication of a larger direct contribution for the 8Be channel at the lower end of the bombarding energy range. 相似文献
19.
The magnetic structure of ferrimagnetic ilmenite Ni2+Mn4+O3 has been investigated by neutron diffraction. Below the Curie temperature (164°C), the spins are oriented into two kinds of ferromagnetic planes perpendicular to the [111] rhomboedral axis, one containing Mn4+ and the other Ni2+ cation. Two successive planes are coupled antiferromagnetically. The experimental magnetic moments are respectively found equal to 1.8 and 2.2 μB for Ni2+ and Mn4+ at room temperature. The positional atomic parameters have been redetermined from nuclear diffraction data taken above the Curie temperature. 相似文献
20.
The independent isomeric yield ratio of148Pr in thermal neutron induced fission of235U has been determined experimentally. The fission product148Pr isomers, extracted directly by on-line mass separation technique, have high-spin (J=4) to low-spin (J=1) isomer ratio of 0.14±0.04 using growth and decay analysis. Statistical model calculation of isomeric yeild ratio using constant initial r.m.s. angular momentumJ rms can not reproduce either present results or other recent measurements of isomer ratios. TheJ rms derived from isomer ratio data in all thermal fissioning systems indicate a wide spread ranging from 2? to 13?. No clear correlation betweenJ rms and isomeric spins or number of neutrons of isomers is found, thus, more model refinements and experimental works should be done in order to evaluate independent isomeric yields correctly. 相似文献