796 research outputs found
Inelastic scattering of protons from He and Li in a folding model approach
The proton-inelastic scattering from He and Li nuclei are
studied in a folding model approach. A finite-range, momentum, density and
isospin dependent nucleon-nucleon interaction (SBM) is folded with realistic
density distributions of the above nuclei. The renormalization factors N
and N on the real and volume imaginary part of the folded potentials are
obtained by analyzing the respective elastic scattering data and kept unaltered
for the inelastic analysis at the same energy. The form factors are generated
by taking derivatives of the folded potentials and therefore required
renormalizations. The values are extracted by fitting the p +
He,Li inelastic angular distributions. The present analysis of
p + He inelastic scattering to the 3.57 MeV excited state, including
unpublished forward angle data (RIKEN) confirms L = 2 transition. Similar
analysis of the p + He inelastic scattering angular distribution leading to
the 1.8 MeV (L = 2) excited state fails to satisfactorily reproduce the data.Comment: one LaTeX file, five PostScript figure
Stability Assessment and Suggestion for Control Measures of a Potential Landslide Slope on NH 94, Uttarakhand Himalaya, India
An unstable slope having few houses which were under distress was studied to arrive at suitable control measures. The slope has undergone subsidence at the road level and there are few houses down the road level which have developed major cracks. The study was focused on identification of causes, assessment of slope stability and suggestions for control measures. The study involved geological and geotechnical investigations, slope stability analysis and monitoring of movements. The paper highlights the field observations and results of the study
Landslide Investigation at Phata Village on Rudraprayag-Kedarnath Road, Uttaranchal — A Case Study
Phata village on the Guptakashi-Gaurikund road in the Mandakini valley of Garhwal Himalaya was affected by a major landslide on 16th July 2001 due to heavy rainfall. The debris flow not only swept away several houses but it also claimed 15 lives. A detailed landslide investigation was carried out to assess the present stability condition. Geotechnical investigation was carried out to determine the soil properties. Seismic refraction survey to determine the overburden thickness was also carried out using Engineering Seismograph. Slope stability analysis was carried out to ascertain the existing stability of the slope. It was found that with rise in pore pressure the slope is marginally stable. The seismic stability analysis showed that seismicity of the order of 0.15g may trigger slips on the slope. The human settlement on the downhill slope may get effected in the eventuality of slide due to seismicity or rain. The paper presents the results of the geological and geotechnical studies which helped to assess the present stability condition
Elastic and total reaction cross sections of oxygen isotopes in Glauber theory
We systematically calculate the total reaction cross sections of oxygen
isotopes, O, on a C target at high energies using the Glauber
theory. The oxygen isotopes are described with Slater determinants generated
from a phenomenological mean-field potential. The agreement between theory and
experiment is generally good, but a sharp increase of the reaction cross
sections from ^{21}O to ^{23}O remains unresolved. To examine the sensitivity
of the diffraction pattern of elastic scattering to the nuclear surface, we
study the differential elastic-scattering cross sections of proton-^{20,21,23}O
at the incident energy of 300 MeV by calculating the full Glauber amplitude.Comment: 9 pages, 8 figure
Measurement of two-halo neutron transfer reaction p(Li,Li)t at 3 MeV
The p(\nuc{11}{Li},\nuc{9}{Li})t reaction has been studied for the first time
at an incident energy of 3 MeV delivered by the new ISAC-2 facility at
TRIUMF. An active target detector MAYA, build at GANIL, was used for the
measurement. The differential cross sectionshave been determined for
transitions to the \nuc{9}{Li} ground andthe first excited states in a wide
range of scattering angles. Multistep transfer calculations using different
\nuc{11}{Li} model wave functions, shows that wave functions with strong
correlations between the halo neutrons are the most successful in reproducing
the observation.Comment: 6 pages, 3 figures, submitted to Physical Review Letter
Lifetimes of states in 19Ne above the 15 O + alpha breakup threshold
The 15O(alpha,gamma)19Ne reaction plays a role in the ignition of Type I
x-ray bursts on accreting neutron stars. The lifetimes of states in 19Ne above
the 15O + alpha threshold of 3.53 MeV are important inputs to calculations of
the astrophysical reaction rate. These levels in 19Ne were populated in the
3He(20Ne,alpha)19Ne reaction at a 20Ne beam energy of 34 MeV. The lifetimes of
six states above the threshold were measured with the Doppler shift attenuation
method (DSAM). The present measurements agree with previous determinations of
the lifetimes of these states and in some cases are considerably more precise
Lifetime of 19Ne*(4.03 MeV)
The Doppler-shift attenuation method was applied to measure the lifetime of
the 4.03 MeV state in 19Ne. Utilizing a 3He-implanted Au foil as a target, the
state was populated using the 20Ne(3He,alpha)19Ne reaction in inverse
kinematics at a 20Ne beam energy of 34 MeV. De-excitation gamma rays were
detected in coincidence with alpha particles. At the 1 sigma level, the
lifetime was determined to be 11 +4, -3 fs and at the 95.45% confidence level
the lifetime is 11 +8, -7 fs.Comment: 6 pages, submitted to Phys. Rev.
Coulomb-nuclear interference in the breakup of Be
Within a theory of breakup reactions formulated in the framework of the post
form distorted wave Born approximation, we calculate contributions of the pure
Coulomb and the pure nuclear breakup as well as those of their interference
terms to a variety of cross sections in breakup reactions of the one-neutron
halo nucleus Be on a number of target nuclei. In contrast to the
assumption often made, the Coulomb-nuclear interference terms are found to be
non-negligible in case of exclusive cross sections of the fragments emitted in
this reaction on medium mass and heavy target nuclei. The consideration of the
nuclear breakup leads to a better description of such data.Comment: 9 pages, latex, 2 figures, to be published in Phys. Rev. C (Rapid
Communication
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