316 research outputs found
Energy Dependence of Total Cross Sections for Reactions with 4, 6he, 6, 7, 9li Nuclei
The paper presents the results of measurement of the total cross sections for reactions 4,6He + Si and 6,7,9Li + Si in the beam energy range 5−50 A⋅MeV. The enhancements of the total cross sections for reaction 6He + Si compared with reaction 4He + Si, and 9Li + Si compared with reactions 6,7Li + Si have been observed. The performed microscopic analysis of total cross sections for reactions 6He + Si and 9Li + Si based on numerical solution of the time-dependent Schrödinger equation for external neutrons of projectile nuclei 6He and 9Li yielded good agreement with experimental data
Parity Inversion And Different Properties of Be11 halo Nuclei
The recent developments of radioactive nuclear beams has opened up the
possibility of exploring a wide variety of nuclei far from the valley of
beta-stability. Of late several theoretical studies have come up in the past
for describing nuclei in these exotic region. Extension of traditional shell
model techniques to explain the exotic feature in the structure of these nuclei
such as, formation of neutron halo large r.m.s radii, soft dipole resonances
etc have confirmed the necessity to modify the single particle shell model
potential when dealing with nuclei far from stability. The ground state nuclear
structure properties of 4Be11 have been calculated in the framework of shell
model using analytically soluble mean field potential given by Ginocchio. The
potential is highly versatile in nature and depends on four parameters, which
define its depth, range and shape. Potential parameters, which generate highly
diffuse shape, account for the small binding and halo structure of the valence
neutron in 4Be11. The problem of ground state parity inversion is also
addressed
Total cross sections for the reactions Be+Si and B+Si
In this paper, the results of measurements of the total cross sections for
the reactions Be+Si and B+Si in the beam
energy range -- MeV are presented. The experimental cross sections
were obtained by detection of the gamma quanta and neutrons accompanying the
interaction of the isotopes of Be and B with Si. It was found that the
cross sections for Be are similar, but significantly exceed those for
Be. A significant increase in the cross sections for Be with
decreasing energy is observed in the entire measured energy range. A
theoretical explanation of the obtained experimental data is given based on the
microscopic model of deformed nuclei and the numerical solution of the
time-dependent Schr\"{o}dinger equation for the outer weakly bound neutrons of
the projectile nuclei. The calculated total reaction cross sections are in good
agreement with the experimental data
Study of internal structures of 9,10Be and 10B in scattering of 4He from 9Be
A study of inelastic scattering and single-particle transfer reactions was
performed by an alpha beam at 63 MeV on a 9$Be target. Angular distributions of
the differential cross sections for the 9Be(4He,4He')9Be*, 9Be(4He,3He)10Be and
9Be(4He,t)10B reactions were measured. Experimental angular distributions of
the differential cross sections for the ground state and a few low-lying states
were analyzed in the framework of the optical model, coupled channels and
distorted-wave Born approximation. An analysis of the obtained spectroscopic
factors was performed.Comment: 16 pages, 7 figures, 3 tables, regular paper, mispritns are corrected
in new versio
Dynamics of nucleus-nucleus collisions and neutron rearrangement in time-dependent approach
The dynamical approach based on numeric solution of the timedependent Schr¨odinger equation is applied to description of transfer and rearrangement of nucleons in nucleus-nucleus collisions. The results of calculation of neutron transfer cross sections for reaction 6He + 197Au and total reaction cross sections for reactions 6He + 28Si, 9Li + 28Si are in agreement with experimental data
Direct mass measurements of 19B, 22C, 29F, 31Ne, 34Na and other light exotic nuclei
We report on direct time-of-flight based mass measurements of 16 light
neutron-rich nuclei. These include the first determination of the masses of the
Borromean drip-line nuclei B, C and F as well as that of
Na. In addition, the most precise determinations to date for N
and Ne are reported. Coupled with recent interaction cross-section
measurements, the present results support the occurrence of a two-neutron halo
in C, with a dominant configuration, and a
single-neutron halo in Ne with the valence neutron occupying
predominantly the 2 orbital. Despite a very low two-neutron separation
energy the development of a halo in B is hindered by the 1
character of the valence neutrons.Comment: 5 page
TOF-Brho Mass Measurements of Very Exotic Nuclides for Astrophysical Calculations at the NSCL
Atomic masses play a crucial role in many nuclear astrophysics calculations.
The lack of experimental values for relevant exotic nuclides triggered a rapid
development of new mass measurement devices around the world. The
Time-of-Flight (TOF) mass measurements offer a complementary technique to the
most precise one, Penning trap measurements, the latter being limited by the
rate and half-lives of the ions of interest. The NSCL facility provides a
well-suited infrastructure for TOF mass measurements of very exotic nuclei. At
this facility, we have recently implemented a TOF-Brho technique and performed
mass measurements of neutron-rich nuclides in the Fe region, important for
r-process calculations and for calculations of processes occurring in the crust
of accreting neutron stars.Comment: 8 pages, 4 figures, submitted to Journal of Physics G, proceedings of
Nuclear Physics in Astrophysics II
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