794 research outputs found

    Inelastic scattering of protons from 6,8^{6,8}He and 7,11^{7,11}Li in a folding model approach

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    The proton-inelastic scattering from 6,8^{6,8}He and 7,11^{7,11}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 NR_R and NI_I 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 β\beta values are extracted by fitting the p + 6,8^{6,8}He,7,11^{7,11}Li inelastic angular distributions. The present analysis of p + 8^8He inelastic scattering to the 3.57 MeV excited state, including unpublished forward angle data (RIKEN) confirms L = 2 transition. Similar analysis of the p + 6^6He 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

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    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

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    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

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    We systematically calculate the total reaction cross sections of oxygen isotopes, 1524^{15-24}O, on a 12^{12}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(11^{11}Li,9^{9}Li)t at 3AA MeV

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    The p(\nuc{11}{Li},\nuc{9}{Li})t reaction has been studied for the first time at an incident energy of 3AA 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

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    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)

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    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 11^{11}Be

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    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 11^{11}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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