Deuteron Stripping Reactions Research Articles

Nonlocal optical potential with core excitation in [formula omitted] and [formula omitted] reactions

We propose a new nonlocal form of the nucleon-nucleus optical potential and demonstrate its reliability. We extend the nonlocal potential to include the excitation of the nuclear core and develop energy-independent proton-Be10 potential reasonably reproducing the experimental data at low energies. We apply the new potential to the study of deuteron stripping and pickup reactions Be10(d,p)11Be and Be11(p,d)10Be using rigorous three-body Faddeev-type equations for transition operators that are solved in the momentum-space partial-wave framework. The achieved description of the experimental data is considerably more successful as compared to previous studies with local potentials. The values of spectroscopic factors consistent with the data are determined, exhibiting only weak energy dependence. The results possibly indicate an increased predicting power of the proposed calculational scheme.

A Brief Review on the Development of Theories of Deuteron Stripping Reactions

As one type of single nucleon transfer reactions, deuteron stripping reaction has been playing an important role in the study of the single particle structure of atomic nuclei. Also, as a typical three-body nuclear reaction, deuteron stripping reaction is also an important subject in the development of direct nuclear reaction theories. We briefly review the history of the study of deuteron stripping reactions, focusing on the evolution of its theoretical descriptions, and the differences and the relations of the Plane Wave Born Approximation(PWBA), the distorted wave Born approximation(DWBA), the Continuum Discretized Coupled Channel method(CDCC), the Adiabatic Wave Approximation(ADWA), and the approach based on the Faddeev equations. Some important problems being currently addressed in deuteron stripping reaction theories and those should be addressed in near future are also discussed, including deuteron strippings at intermediate and high energies, theory for transfer to continuum states of the residue nuclei, applications of dispersive optical model potentials and non-local potentials, etc. Some preliminary results of our theoretical calculations for deuteron stripping at intermediate and high energies are presented.

What kind of optical model potentials should be used for deuteron stripping reactions?

This paper presents the results of a study that compares CTOM, a microscopic optical model potential (OMP), which is an optical model co-created by the China Nuclear Data Center & Tuebingen University, to CH89, which is a typical phenomenological OMP. The respective OMPs were tested by applying them to the modelling of nucleon elastic scattering and (d, p) transfer reactions involving 14C, 36S, and 58Ni targets at both low and relatively high energies. The results demonstrated that although both potentials successfully accounted for the angular distributions of both the elastic scattering and transfer cross sections, the absolute values of the transfer cross sections calculated using CTOM were approximately 25% larger than those calculated using CH89. This increased transfer cross sections allowed CTOM to produce single particle strength reduction factors for the three reactions that were consistent with those extracted from (e, e′ p) reactions as well as with more recent (p, 2p) and (p, pn) reactions. Notch tests suggested that nucleon elastic scattering and transfer reactions are sensitive to different regions of the OMP; accordingly, phenomenological OMPs, which are constrained only by elastic scattering cross sections, may not be sufficient for nucleon transfer reactions. Therefore, we suggest that microscopic OMPs, which reflect more theoretical considerations, should be preferred over phenomenological ones in calculations of direct nuclear reactions.

Polarization of Nucleons in the Deuteron Stripping Reaction on Nuclei

A general analytical expression has been obtained in the diffraction approximation for the polarization of nucleons arising in the deuteron stripping reaction on nuclei at intermediate energies of the incident particles. A tabulated density distribution of the target nucleus and a realistic wave function of the deuteron with correct asymptotic limits at large internucleon distances were used in the calculations. The nucleon-nucleus phase shifts were calculated in the Glauber formalism using the double folding potential. The calculated angular dependencies for the vector analyzing power $A_{y}$ of the reaction $^{3}\text{He}(\vec{d},p)^{4}\text{He}$ are found to be in satisfactory agreement with the corresponding experimental data.

Polarized-deuteron stripping reaction at intermediate energies

A general analytical expressions for the cross-section and the polarization of nucleons arising in the inclusive deuteron stripping reaction have been derived in the diffraction approximation. The nucleon–nucleus phases were calculated in the framework of Glauber formalism and making use of the double-folding potential. The tabulated distributions of the target nucleus density and the realistic deuteron wave function with correct asymptotic at large nucleon–nucleon distances were used. The calculated angular dependences for the cross-sections and the analyzing powers of the [Formula: see text] reaction are compared with corresponding experimental data.

Deuteron-induced nucleon transfer reactions within anab initioframework: First application top-shell nuclei

Background: Low-energy transfer reactions in which a proton is stripped from a deuteron projectile and dropped into a target play a crucial role in the formation of nuclei in both primordial and stellar nucleosynthesis, as well as in the study of exotic nuclei using radioactive beam facilities and inverse kinematics. Ab initio approaches have been successfully applied to describe the $^3$H$(d,n)^4$He and $^3$He$(d,p)^4$He fusion processes. Purpose: An ab initio treatment of transfer reactions would also be desirable for heavier targets. In this work, we extend the ab initio description of $(d,p)$ reactions to processes with light $p$-shell nuclei. As a first application, we study the elastic scattering of deuterium on $^7$Li and the ${}^{7}$Li($d$,$p$)${}^{8}$Li transfer reaction based on a two-body Hamiltonian. Methods: We use the no-core shell model to compute the wave functions of the nuclei involved in the reaction, and describe the dynamics between targets and projectiles with the help of microscopic-cluster states in the spirit of the resonating group method. Results: The shape of the excitation functions for deuteron impinging on ${}^{7}$Li are qualitatively reproduced up to the deuteron breakup energy. The interplay between $d$-$^7$Li and $p$-$^8$Li particle-decay channels determines some features of the ${}^{9}$Be spectrum above the $d$+${}^{7}$Li threshold. Our prediction for the parity of the 17.298 MeV resonance is at odds with the experimental assignment Conclusions: Deuteron stripping reactions with $p$-shell targets can now be computed ab initio, but calculations are very demanding. A quantitative description of the ${}^{7}$Li($d$,$p$)${}^{8}$Li reaction will require further work to include the effect of three-nucleon forces and additional decay channels, and improve the convergence rate of our calculations.

Deuteron stripping on nuclei at intermediate energies

A general analytical expression for the double differential cross section of deuteron stripping reaction on nuclei at intermediate energies of incident particles was obtained in the diffraction approximation. Nucleon–nucleus phases were calculated in the framework of Glauber formalism and making use of the double-folding potential. The exact wave function of deuteron with correct asymptotics at short and long distances between nucleons was used. The calculated angular dependencies of cross sections are in good agreement with corresponding experimental data.

Asymptotic normalization coefficients and spectroscopic factors from deuteron stripping reactions

We present the analysis of three deuteron stripping reactions, $^{14}\mathrm{C}(d,p)^{15}\mathrm{C},^{58}\mathrm{Ni}(d,p)^{59}\mathrm{Ni}$, and $^{116}\mathrm{Sn}(d,p)^{117}\mathrm{Sn}$ using the combined method [A. M. Mukhamedzhanov and F. M. Nunes, Phys. Rev. C 72, 017602 (2005)], in which each reaction is analyzed at low and significantly higher energies. At low energies all these reactions are peripheral and the experimental asymptotic normalization coefficients (ANCs) are determined with accuracy about $10%$. At higher energies we determine the spectroscopic factors (SFs) by fixing the normalization of the peripheral parts of the reaction amplitudes governed by the ANCs found from the low-energy data. The combined method imposes a strict limitation on the variation of the geometrical parameters of the single-particle potential, which can be arbitrarily taken in the standard approach. By checking the compatibility of the ANCs and SFs using the combined method we reveal the flaw in the contemporary nuclear reaction theory in treating the nuclear interior, which is the most crucial part in the determination of the SFs.

Publisher’s Note: Nonlocality in Deuteron Stripping Reactions [Phys. Rev. Lett.110, 112501 (2013)

Publisher’s Note: Nonlocality in Deuteron Stripping Reactions [Phys. Rev. Lett.<b>110</b>, 112501 (2013)

Nonlocality in deuteron stripping reactions.

We propose a new method for the analysis of deuteron stripping reactions, A(d,p)B, in which the nonlocality of nucleon-nucleus interactions and three-body degrees of freedom are accounted for in a consistent way. The model deals with equivalent local nucleon potentials taken at an energy shifted by ∼40 MeV from the "E(d)/2" value frequently used in the analysis of experimental data, where E(d) is the incident deuteron energy. The "E(d)/2" rule lies at the heart of all three-body analyses of (d, p) reactions performed so far with the aim of obtaining nuclear structure properties such as spectroscopic factors and asymptotic normalization coefficients that are crucial for our understanding of nuclear shell evolution in neutron- and proton-rich regions of the nuclear periodic table and for predicting the cross sections of stellar reactions. The large predicted shift arises from the large relative kinetic energy of the neutron and proton in the incident deuteron in those components of the n+p+A wave function that dominate the (d, p) reaction amplitude. The large shift reduces the effective d-A potentials and leads to a change in predicted (d, p) cross sections, thus affecting the interpretation of these reactions in terms of nuclear structure.

Nuclear threshold effects and neutron strength functions

The present work is devoted to study of spectroscopic aspects, in terms of neutron strength function, for the threshold effects with non-light nuclei. Relations to the neutron strength functions of the anomal effects observed at threshold of neutron analogue channel, in deuteron stripping reactions on A ≈ 90 mass target nuclei and in nucleon mirror reactions with A ≈ 30 nuclei, are established. It is proved that these threshold effects follow the mass dependance of the neutron strength functions.

THE DEUTERON STRIPPING ANOMALY AT THRESHOLD OF ANALOGUE CHANNEL AND THE 3 - p WAVE NEUTRON STRENGTH FUNCTION

We prove in this paper that the magnitude of anomaly in deuteron stripping reactions on A ≈ 80–110 mass target nuclei, at threshold of analogue channel, is proportional to the 3 - p wave neutron strength function. The result is obtained from analysis, within an empirical approach and computational frameworks, of the cross-section and analyzing power experimental data related to this (d,p) anomaly.

Deuteron stripping as a probe of the proton halo in17F

The deuteron stripping reactions are presented as a method of determining particle distribution within possible halo nuclei. Distributions of the last proton in {sup 17}F and the last neutron in {sup 17}O are extracted from a comparison of experimental and theoretical reaction cross sections. It is found that the first excited state of {sup 17}F is a proton halo state and that the halo behavior can be explained purely in terms of binding-energy effects. {copyright} {ital 1999} {ital The American Physical Society}

Comparison between the ground state transitions of the sub-Coulomb deuteron stripping reactions on 6Li

By means of recoil nuclei spectroscopy the 6Li(d,p 0) 7Li and 6Li(d,n 0) 7Be mirror reactions have been measured for deuteron energies between 65 and 135 keV. The results have been compared with theoretical calculations including effects of the isospin mixed subthreshold resonance state in 8Be.

Deuteron-stripping reaction at intermediate energies

The inclusive deuteron-stripping-reaction differential and integrated cross sections are calculated on the basis of diffraction theory with allowance for nuclear surface diffuseness. It is shown that this process includes two mechanisms. The results of the calculations are in good agreement with the 650 MeV deuteron experimental data.

Three-body formalism for deuteron stripping reactions

A three-body formalism for deuteron stripping reactions has been developed. The equations of Altet al (1967) (AGS) for the three particle system (target A, n, p) are reduced to a set of coupled one-dimensional integral equations with the use of (i) angular momentum basis for representation and (ii) separable approximation for the two bodyt-matrices (which delineate the interactions between the particle pairs). The on-shell solutions of this set of integral equations are then related to the cross sections of the rearrangement processes. The inputs in this calculation, viz., the separable interactions between the particle pairs in the respective channels are simply constructed from the respective two body bound state in accordance with the bound state approximation (BSA) conforming to the ‘unitarity’ requirement. Using this formalism preliminary calculations for the (d, p) and (d, n) reaction cross sections on16O have been carried out and they seem to have considerable semblance with the observed cross sections.

Deuteron break-up contribution to stripping and pick-up reactions

A simple prescription is given for calculating the effect of the break-up channel in deuteron stripping and pick-up reactions, and it is found to work for a wide range of nuclei.

A new estimate of break-up in deuteron-induced reactions

The break-up contribution to the deuteron stripping and pick-up reaction is obtained from an integral equation.

Antisymmetrization corrections to three-body models of deuteron stripping reactions

A recent suggestion that antisymmetrization corrections to transfer reactions may be treated through a generalization of the Johnson—Soper adiabatic prescription for deuteron breakup is examined and shown to be inconsistent. An alternative technique for treating antisymmetrization corrections in the presence of strong breakup which gives quantitatively different results is applied to recent 116Sn(d,p) 117Sn(g.s.) data at 79 MeV.

The Application of a Deuteron Stripping Reaction to Investigate Extreme-Pressure Films

Extreme-pressure (EP) additives containing sulphur have been tested using a fourball machine and the structure and thickness of the surface films which formed during wear tests have been studied using conventional methods of physical analysis. A nuclear technique based on a deuteron-proton stripping reaction, was employed to give complementary information (unobtainable by more usual techniques) which produced a better understanding of the structure and formation of such EP films.