共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
3.
Mirjalili A. Yazdanpanah M. M. 《The European Physical Journal A - Hadrons and Nuclei》2011,47(5):1-10
The diffusion-effusion model has been used to analyse the release and yields of Fr and Cs isotopes from uranium carbide targets of very different thicknesses (6.3 and 148 g/cm2) bombarded by a 1 GeV proton beam. Release curves of several isotopes of the same element and production efficiency versus decay half-life are well fitted with the same set of parameters. Comparison of efficiencies for neutron-rich and neutron-deficient Cs isotopes enables separation of the contributions from the primary (p + 238U) and secondary (n + 238U) reactions to the production of neutron-rich Cs isotopes. A rather simple calculation of the neutron contribution describes these data fairly well. The FLUKA code describes the primary and secondary-reaction contributions to the Cs isotopes production efficiencies for different targets quite well. 相似文献
4.
A. Mirjalili M. M. Yazdanpanah 《The European Physical Journal A - Hadrons and Nuclei》2012,48(5):1-10
Target mass correction (TMC) is employed to amend the polarized helium structure functions, 3He . The structure function can be obtained via the convolution of the light cone momentum distribution with the polarized structure of the proton and neutron. The calculation of the polarized structure function of the nucleon is based on the constituent quark model. The analytical result for 3He polarized structure function at low values of Q2 is not in good agreement with the available experimental data. The reliability of calculations is increased using TMC effect. New comparison confirms a better agreement with the experimental data. 相似文献
5.
6.
A final-state-effects formalism suitable to analyze the high-momentum response of Fermi liquids is presented and used to study the dynamic structure function of liquid 3He. The theory, developed as a natural extension of the Gersch-Rodriguez formalism, incorporates the Fermi statistics explicitly through a new additive term which depends on the semidiagonal two-body density matrix. The use of a realistic momentum distribution, calculated using the diffusion Monte Carlo method, and the inclusion of this additive correction allows for good agreement with available deep-inelastic neutron scattering data. 相似文献
7.
Evgenji Krasnoperov Evgenji E. Meilikhov Dimitrji Eschenko Dierk Herlach Elvezio Morenzoni Ulrich Zimmermann Fredy N. Gygax Alexander Schenck 《Hyperfine Interactions》1994,87(1):1017-1022
We report the first measurements of the positive-muon spin depolarization in liquid3He. The relaxation of the muon and muonium precession has been studied in transverse, longitudinal, and zero magnetic fields in the temperature range 0.5–2.5 K. The results are discussed in terms of two different depolarization mechanisms: recombinational depolarization (i.e. slow muonium formation) and magnetic relaxation due to the3He nuclear magnetic moments. 相似文献
8.
The phase transitions of liquid 3He are described by truncations of an exact nonperturbative renormalization group equation. The location of the first-order transition lines and the jump in the order parameter are computed quantitatively. At the triple point we find indications of partially universal behavior. We suggest experiments that could help to determine the effective interactions between fermion pairs. 相似文献
9.
10.
11.
We present the first measurements of the thermal conductivity of spin-polarized normal liquid 3He. Using the rapid melting technique to produce nuclear polarizations up to 0.7, and a vibrating wire both as a heater and a thermometer, we show that, unlike the viscosity, the conductivity increases much less than predicted for s-wave scattering. We suggest that this might be due to a small probability for head-on collisions between quasiparticles. 相似文献
12.
13.
14.
The superfluid transitions temperature is calculated from the microscopic theory of a Fermi liquid in terms of the Landau parameters and one unknown scale factor. Determining the latter from the observed transition in 3He leads to an estimate that the superfluid transition in 3He4He mixtures may be presently observable. 相似文献
15.
16.
We present new quantum Monte Carlo calculations of the ground-state energy of liquid 3He using backflow and 3-body wavefunctions and twist-averaged boundary conditions. We estimate the effects of the 3-body potential and compare to experimental measurements of the unpolarized equation of state and the magnetic susceptibility. There is still a large discrepancy with respect to the magnetic susceptibility, requiring either improved nodal surfaces or going beyond the fixed-node method. 相似文献
17.
Summary We calculate the3He−4He chemical potential and change in volume in bulk liquid4He employing integral equation and Monte Carlo procedures. Detailed numerical results on these quantities and their dependence
on bulk density and on the isotopic-mass difference are presented and discussed.
This work has been supported by the Deutsche Forschungsgemeinschaft under grant Ri 267 and by the U.S. Department of energy
under contract DE-AC 02-76 ER03077 and by the NSF under grant DMR-77-18329. 相似文献
18.
19.
《Solid State Communications》1986,59(8):575-577
We present a microscopic calculation of the wave number dependent quasiparticle interaction and its variation with pressure in liquid 3He. Calculation of the variation of the Landau parameters Fs0 and Fa0 with pressure is also presented. The theory is capable of reproducing qualitatively some of the salient features seen in experiments in liquid 3He. 相似文献