The study of inelastic scattering and multi-nucleon transfer reactions was performed by bombarding a 9Be target with a 3He beam at an incident energy of 30 MeV. Angular distributions for ...9Be(3He,3He)9Be, 9Be(3He,4He)8Be, 9Be(3He,7Be)5He, 9Be(3He,6Li)6Li and 9Be(3He,7Li)5Li reaction channels were measured. Cross sections for channels leading to unbound 5Heg.s., 5Lig.s. and 8Be systems were obtained from singles measurements where the relationship between the energy and the scattering angle of the observed stable ejectile is constrained by two-body kinematics. Information on the cluster structure of 9Be was obtained from the transfer channels. It was concluded that cluster transfer is an important mechanism in the investigated nuclear reactions. In the present work an attempt was made to estimate the relative strengths of the interesting 8Be+n and 5He+α cluster configurations in 9Be. The branching ratios have been determined confirming that the 5He+α configuration plays an important role. The configuration of 9 Be consisting of two bound helium clusters 3He+6He is significantly suppressed, whereas the two-body configurations 8Be+n and 5He+α including unbound 8Be and 5He are found more probable.
Experimental cross sections of formation of isotopes
46
Sc (in reaction
6
He +
45
Sc),
196,198
Au (in reaction
6
He +
197
Au), and
65
Zn (in reaction
6
He +
64
Zn) are analyzed. The time-dependent ...Schrödinger equation for the outer neutrons of
6
He and
197
Au nuclei is solved numerically to calculate the probability of neutron transfer and transfer cross sections. In reaction
6
He +
197
Au, the contribution of fusion and subsequent evaporation to experimental data can be neglected, while the corresponding contributions to reactions
6
He +
45
Sc and
6
He +
64
Zn are considerable. Fusion–evaporation is taken into account using the computational code of the NRV knowledge base. The results of calculations are in satisfactory agreement with the experimental data.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Angular distributions of protons, deuterons, tritons and alpha particles emitted in the reaction2H +9Be at E lab =19.5 MeV were measured with an aim to shed light on the internal cluster structure of ...9 Be and to study possible cluster transfer of5He. The analyses suggest a significant contribution of five nucleon transfer in the reaction channel9Be ( d ,4He)7Li.
Angular distributions of protons, deuterons, tritons and alpha-particles emitted from the reactions in the2H+9Be-system at Elab=19.5 MeV were measured with an aim to shed light on the internal ...cluster structure of9Be and the study of possible cluster transfer of5He. The analyses suggest a significant contribution of five-nucleon transfer in the reaction channel9Be(d,4He)7Li.
Abstract
Both K-shell x-ray emission spectroscopy and fluorescence spectroscopy are well-accepted diagnostics for experimental studies of warm dense matter and hot dense matter (HDM). Until now, ...however, this diagnosis has been used for the study of dense matter with temperatures lower than 100 eV or with temperatures above 1 keV. In this work, we have demonstrated the possibility of using K-shell emission spectroscopy for an intermediate temperature range of 100s eV to study dense plasma. Here, we discuss an analysis of the HDM emission spectra of a solid-state copper with temperatures up to a few hundreds of electronvolts heated by laser-accelerated charged particles.
We investigate the formation of a laser-produced magnetized jet under conditions of a varying mass ejection rate and a varying divergence of the ejected plasma flow. This is done by irradiating a ...solid target placed in a 20 T magnetic field with, first, a collinear precursor laser pulse (10^{12} W/cm^{2}) and, then, a main pulse (10^{13} W/cm^{2}) arriving 9-19 ns later. Varying the time delay between the two pulses is found to control the divergence of the expanding plasma, which is shown to increase the strength of and heating in the conical shock that is responsible for jet collimation. These results show that plasma collimation due to shocks against a strong magnetic field can lead to stable, astrophysically relevant jets that are sustained over time scales 100 times the laser pulse duration (i.e., >70 ns), even in the case of strong variability at the source.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
A method for direct and model-independent measurements of the full cross section for the reaction σ
R
is described, along with the physical setting and the results from measuring σ
R
(
E
) for the ...reaction
6
He+
197
Au in the energy region near the Coulomb barrier. A comparison of cross section values measured by the direct method with a summed cross section of the reaction’s
xn
evaporation channels (
x
= 2–7) and a neutron’s disruption-pickup channels measured by means of activation analysis is presented, along with the familiar value in the literature for a full cross section obtained from processing with an optical model of experimental differential cross sections of the elastic scattering of
6
He on
197
Au.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
New experimental measurements of the total reaction cross sections for the {sup 6}He + {sup nat}Si and {sup 9}Li + {sup nat}Si processes in the energy range of 5 to 40 A MeV are presented. A modified ...transmission method based on high-efficiency detection of prompt n–γ radiation has been used in the experiment. A bump is observed for the first time in the energy dependence σ{sub R}(E) at E ∼ 10–30 A MeV for the {sup 9}Li + {sup nat}Si reaction, and existence of the bump in σ{sub R}(E) at E ∼ 10–20 A MeV first observed in the standard transmission experiments is experimentally confirmed for the {sup 6}He + {sup nat}Si reaction. Theoretical analysis of the measured {sup 6}He + {sup nat}Si and {sup 9}Li + {sup nat}Si reaction cross sections is performed within the microscopic double folding model. Disagreement is observed between the experimental and theoretical cross sections in the region of the bump at the energies of 10 to 20 A MeV, which requires further study.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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