共查询到20条相似文献,搜索用时 15 毫秒
1.
The hole-vibration coupling in the Z = 50 region is investigated by calculating the level structure of 115In. Four proton-hole states are coupled with quadrupole and octupole core vibrations. The phonon energies and the amplitudes of the vibrational motions are taken from experiment, while the single-hole energies are treated as free parameters. Most of the observed features of a quintet of states with , which have enhanced E2 transition strengths to the ground state, are well reproduced by the theory. The hole-vibration coupling produces a strong fragmentation of the single-hole strengths. This is quite in agreement with the results of (d, 3He) experiments on 116Sn. 相似文献
2.
Continuous radiation (bremsstrahlung) from a 2 MeV electron accelerator has been used to excite seven nuclear levels in 115In, at 1133, 1291, 1449, 1464, 1487, 1498 and 1610 keV. Mean-life values were calculated for the first five levels and the δ2 ratio was also determined for those at 1133 and 1464 keV. 相似文献
3.
We have studied at room temperature the intensities and the Knight shifts of the nuclear magnetic resonances of 69Ga, 71Ga, and 51V in V3?xFexGa for Fe concentrations ranging from x = 0.04 to x = 0.6. The results interpreted in terms of a redistribution of the conduction electrons and a paramagnetism due to the Fe impurities. 相似文献
4.
Energy levels of 69Ge are populated by the 69Ga(p, n) reaction. Angular distributions and DSAM are used to extract information on spins and γ-decay properties of the levels of this nucleus. The observed structure of the negative- and positive-parity states is compared with the predictions of the one- and three-particle-cluster—core coupling model. 相似文献
5.
6.
Gamma rays in the range 5.4–6.7 MeV have been studied for 31 s-wave neutron resonances of 115In, selected by time of flight in the range 3–430 eV. In a subsidiary experiment, spin J = 5 has been assigned to 17 and J = 4 to 14 resonances by measuring intensity variations of some strong low-energy transitions. The reduced widths averaged over all initial states of the same spin have been estimated for 41 primary transitions: these values have provided information on the spin and parity of the corresponding 116In final states. Overall mean values of E1 and M1 radiative strength have been calculated. The width distribution has been fitted with a χ2 function with ν = 1.10+0.27?0.09 degrees of freedom for M1 and ν = 1.42 + 0.014?0.08 for E1 radiation. An estimate of the spin cut-off parameter σ = 3.6?0.4+ 0.8 has been derived. A non-statistical effect already evidenced in previous measurements has been confirmed, consisting of a strong modulation of the radiative strength against resonance energy, correlated also with the local neutron strength function. In addition, it has now been shown that this structure is due to E1 radiation only. 相似文献
7.
The yields of isomeric states in 89Y, 115In and 197Au produced by the (γ, γ') reaction have been measured in the energy range 100–800 MeV by the activation method. From the yields the cross sections have been deduced. Large cross sections around the first pion resonance are found. The experimental results are compared to calculations based on the impulse approximation. 相似文献
8.
Mechanisms of the reactions of 12C and 14N with 115In have been investigated by measuring the angular distributions of the target residues. Various possible transfer mechanisms are discussed with the help of kinematic analysis and a semiclassical transfer model. Interesting secondary (or tertiary) peaks are seen near 90 in the angular distributions for most target residues. 相似文献
9.
W.H.A. Hesselink B.R. Kooistra L.W. Put R.H. Siemssen S.Y. Van Der Werf 《Nuclear Physics A》1974,226(2):229-236
The 116Sn(d, 3He)115In reaction has been investigated at Ed = 50 MeV. Thirteen transitions to states up to 3 MeV excitation energy were studied. The measured angular distributions were compared with DWBA calculations and transferred angular momenta and spectroscopic factors were deduced. Levels at 1.04, 2.23 and 2.52 MeV were found to be excited most likely by l = 3 angular momentum transfer in contrast to previous investigations at lower incident energies in which no l = 3 transitions have been observed. 相似文献
10.
F. Rigaud G.Y. Petit J. Dalmas J.L. Irigaray M. Suffert F. Saporetti G. Longo R. Guidotti 《Nuclear Physics A》1979,326(1):26-36
Spectra of high-energy photons following the radiative capture of 8–22 MeV protons in 110Cd and 111In are measured. The (p, γ) differential cross sections at 90° with respect to the beam axis is deduced from the integration of measured spectra. The photon angular distribution is measured for the reaction, too, at 13 MeV incident energy. Satisfactory agreement between theory and experiment is obtained by using the direct-semidirect model for dipole and quadrupole fast nucleon radiative capture. 相似文献
11.
T. Bǎdicǎ C. Ciortea S. Dima A. Gelberg A. Petrovici I. Popescu 《Nuclear Physics A》1974,222(1):168-172
The magnetic moment of the 828 keV level in 115In was found to be 0.80 ± 0.14 μN by measuring the γ-γ integral angular correlation perturbed by an external magnetic field. Several assumptions concerning the nature of the state investigated have been discussed. 相似文献
12.
The cross sections for the reactions 197Au(n, γ)198Au and 115In(n, γ)116mIn have been measured with the activation method in the neutron energy region 2.0–7.7 MeV. The influence of background neutrons on the results was studied in considerable detail. The main problems are caused by low-energy neutrons produced by charged-particle reactions in the target material and secondary neutrons from nonelastic reactions in the sample and surrounding materials.The measured capture cross sections are generally lower than previous results and the deviation tends to increase with increasing neutron energy. The data are also compared with calculations based on the compound-nucleus model and quite good agreement is obtained. 相似文献
13.
Differential cross-section and analysing-power excitation functions were measured for elastic proton scattering from Ep = 3.6–6.4 MeV at θc.m. = 90°, 115.8°, 129.8° and 155.3°. Differential cross-section angular distributions were measured at 3.56, 3.94, 5.78 and 8.98 MeV and analysing-power angular distributions at 5.78 and 8.98 MeV. Optical-model parameters were deduced from these distributions. Resonance parameters were determined for eight analogue resonances in 71Ga and neutron spectroscopic factors were calculated. These were compared with the results of previous (p, p) cross-section analyses and the results of (d, p) reactions leading to states in 71Zn. 相似文献
14.
W.F. Van Gunsteren 《Nuclear Physics A》1976,265(2):263-279
15.
G.L. Belenkii E.Yu. Salaev R.A. Suleimanov N.A. Abdullaev V.Ya. Shteinshraiber 《Solid State Communications》1985,53(11):967-971
Experimental investigations of thermal expansion parallel and perpendicular to the layers plane of layer crystals GaS, GaSe and InSe are described. The obtained results are analized together with known thermal expansion data on graphite, C, and boron nitride, BN. Theoretical calculations of linear expansion coefficients are carried out on the basis of the model of highly anisotropic crystal. It is shown, that the negative thermal expansion in the layer plane, typical of layer crystals, is due to “bending” waves, acoustic waves propagating in the layer plane and polarized perpendicular to this plane (TA⊥ mode) 相似文献
16.
D.A. Hutcheon D.M. Sheppard P. Kitching J.M. Davidson C.W. Luursema L.E. Carlson 《Nuclear Physics A》1975,245(2):306-316
A pulsed proton beam and coaxial Ge(Li) detector were used to study the time dependence of the angular distribution of γ-rays resulting from the decay of the 879 keV state in 70Ga, as excited by the 70Zn(p, n)70Ga reaction. A strong time-dependent attenuation of anisotropy was observed. The unperturbed value of the angular distribution is consistent with the assignment of spin I = 4 to the 879 keV level. The half-life of the 879 keV state was measured to be . 相似文献
17.
Summary Calculations of the neutrino-capture cross sections for69,71Ga based on a microscopic treatment of the Gamow-Teller matrix elements are presented. A strong enhancement of the cross-section
for high-energetic neutrinos is found compared to previous phenomenological estimates. As a consequence the present assumptions
on the signal from8B neutrinos in71Ga have to be revised. A rather large solar model dependent background of8B neutrinos has to be expected in a gallium solarneutrino experiment together with the pp signal. This will complicate the
interpretation of such an experiment particularly in the case of neutrino oscillations with not maximum mixing angle. The
calculations yield a larger sensitivity of the gallium detector than assumed previously for galactic neutrinos.
Riassunto Si presentano i calcoli delle sezioni d'urto di cattura neutrinica per69,71Ga basati su un trattamento microscopico degli elementi di matrice di Gamow-Teller. Si trova un forte aumento della sezione d'urto rispetto a stime fenomenologiche precedenti. Di conseguenza gli assunti attuali sul segnale dai neutrini8B in71Ga devono essere riveduti. Si prevede un sottofondo abbastanza grande, dipendente dal modello solare di neutrini di8B in un esperimento di neutrini solari di71Ga con il segnale pp. Ciò complicherà l'interpretazione di questo esperimento particolarmente nel caso di oscillazioni neutriniche con angolo di mescolamento non massimo. I calcoli danno una sensibilità maggiore del rivelatore di gallio rispetto a quanto precedentemente assunto per i neutrini galattici.
Резюме Проводятся вычисления поперечных сечений захвата нейтрино в69,71Ga на основе микроскопического рассмотрения матричных элементов Гамова-Теллера. Обнаружено сильное увеличение поперечного сечения для нейтрино высоких энергий по сравнению с предыдущими феноменологическими оценками. В рамках предложенного подхода заново определяется сигнал от8B-нейтрино в71Ga. Отмечается наличие довольно большого фона нейтрино. Это приводит к проблемам при интерпретации эксперимента с солнечными нейтрино в галлии в случае нейтринных осцилляций с немаксимальным углом смешивания. Вычисления приводят к большей чувствительности галлиевого детектора, чем предполагалось ранее для галактических нейтрино.相似文献
18.
The isotopes 107Sn and 107In were produced through the 106Cd(3He, 2n)107Sn and 106Cd(3He, pn)107In reactions. They were studied by means of γ-spectroscopy, excitation functions, γγ coincidences and angular distributions of γ-rays. A level scheme is proposed for the newly discovered 107Sn, and new states belonging to 107In are given. Microscopic calculations have been performed in a three-quasiparticle approximation for a large number of tin isotopes in order to get a wide view of the systematic evolution of the various states. 相似文献
19.
The origin of the high- and low-frequency K-satellites of 31Ga, 32Ge, 33 As is explain on the basis of Hayasi's theory of quasi-stationary states. It is shown that the same QSS difference gives rise to a particular satellite of either type in all the elements. The results are compared with those of multiple ionisation theory. 相似文献
20.
It is well known that the observation of a nonzero Fermi matrix element for a β-transition between states that differ in isospin can provide information about the relative isospin purity of the states involved. We have determined the log ft value for the 0+ → 0+ (ΔT ≠ 0) β-transition in decay as 6.516 ± 0.020. From this log ft value, we have deduced |MF| = (43.4 ± 1.1) × 10?3, |α| = (21.7 ± 0.6) × 10?3 and |〈VCD〉| = 41.7 ± 1.1 keV, where MF,α2 and 〈VCD〉 represent the Fermi matrix element, isospin impurity and Coulomb matrix element, respectively. The Coulomb matrix element of 41.7 keV found for 64Ga is one of the largest known from β-decay experiments. The experimental procedure involved a careful measurement of the intensity of the annihilation radiation relative to that of the other γ-rays from 64Ga decay. As a by-product, we have obtained an improved 64Ga decay scheme. We have also summarized the existing information on the isospin impurities of nuclear states as deduced from β-decay experiments. 相似文献