One-two step transfer observed in 16O+11B nuclear system

2015 ◽  
Vol 24 (06) ◽  
pp. 1550047 ◽  
Author(s):  
Sh. Hamada ◽  
N. Burtebayev
Keyword(s):  
Angular Distribution ◽  
Cross Section ◽  
Born Approximation ◽  
Optical Model ◽  
Ion Beam ◽  
Nuclear System ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
Cluster Transfer ◽  
Spectroscopic Amplitude

The angular distribution measurements for 16O ion beam elastically scattered from 11 B target of thickness 32.9μg/cm2 at energy 22.4 MeV had been performed in the cyclotron DC-60 INP NNC RK. The previous measurements for 16 O +11 B nuclear system at energies 27, 30, 32.5 and 35 MeV showed an increase in the differential cross-section at backward angles due to the contribution of cluster transfer. Such transfer process could not be described in terms of optical model (OM); it could be described within the framework of distorted wave Born approximation method implemented in FRESCO code. Both one (5 Li ) and two-step transfer (proton transfer followed by Alpha transfer) were taken into considerations. We have extracted the spectroscopic amplitude (SA) for the configuration 16 O →11 B +5 Li .

Simplistic distorted-wave Born approximation interpretation of the 11Li(p,t)9Li reaction

2019 ◽  
Vol 28 (07) ◽  
pp. 1950050
Author(s):  
A. A. Cowley
Keyword(s):  
Angular Distribution ◽  
Cross Section ◽  
Born Approximation ◽  
Incident Energy ◽  
Theoretical Treatment ◽  
Large Radius ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
Neutron Cluster ◽  
Coupled Channel

The reaction [Formula: see text]Li([Formula: see text])9Li(gs) at an incident energy of 4.3[Formula: see text]MeV is interpreted in terms of a simplistic distorted-wave Born approximation, which assumes simultaneous transfer of the halo neutrons. The halo neutrons involved in the reaction is treated as either a di-neutron cluster or individual entities. Either of these approaches appears to be a good approximation of the reaction mechanism, as would be expected from earlier studies. The dominant contribution to the yield of the reaction comes from the known (2[Formula: see text])2 neutron structure component of the ground state of [Formula: see text]Li. Furthermore, the cross-section angular distribution seems to be relatively insensitive to the fact that [Formula: see text]Li has an anomalously large radius due to its Borromean halo properties. Significantly this simple treatment of the reaction is in much better agreement with the experimental angular distribution than previous sophisticated calculations. The relevance and limitations of a more advanced theoretical treatment which includes coupled channel and sequential transfer are discussed in the context of the present results.

Analysing powers and differential cross sections of (3He,p) reactions on 6Li and 7Li at low energy

1995 ◽  
Vol 73 (1-2) ◽  
pp. 74-84 ◽  
Author(s):  
D. Baddou ◽  
C. Rioux ◽  
R. J. Slobodrian ◽  
J. M. Nelson
Keyword(s):  
Cross Sections ◽  
Differential Cross ◽  
Born Approximation ◽  
Low Energy ◽  
Angular Distributions ◽  
Differential Cross Sections ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
Nucleon Transfer ◽  
Cluster Transfer

Angular distributions of the differential cross sections and analysing powers were measured at an energy of 4.6 MeV. The results are compared with the distorted wave Born approximation predictions for two-nucleon transfer and for a deuteron-cluster transfer. The agreement is qualitative at best, and a discussion of alternatives to improve it is presented.

Measurement and analysis of 10B +12C elastic scattering at energy of 41.3MeV

2019 ◽  
Vol 28 (04) ◽  
pp. 1950028 ◽  
Author(s):  
N. Burtebayev ◽  
M. Nassurlla ◽  
A. Sabidolda ◽  
S. B. Sakuta ◽  
A. A. Karakhodjaev ◽  
...  
Keyword(s):  
Experimental Data ◽  
Elastic Scattering ◽  
Cross Sections ◽  
Optical Model ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
Measurement And Analysis ◽  
Spectroscopic Amplitude ◽  
Deuteron Transfer ◽  
Forward Hemisphere

Angular distribution of the [Formula: see text] elastic scattering was measured at [Formula: see text][Formula: see text]MeV. Experimental data showed a significant increase in differential cross-sections at backward angles. The optical model with phenomenological potentials reproduces well the experimental cross-sections in the region of the angles of the forward hemisphere, but is not able to explain the increase in cross-sections at large angles. The distorted wave Born approximation method was used to reproduce the experimental data at large angles [Formula: see text] by taking into consideration a deuteron transfer. Spectroscopic amplitude has been extracted for the configuration [Formula: see text]C[Formula: see text]B + [Formula: see text] from the analysis.

Superoperator methods of calculating cross sections: II. Distorted wave Born approximation

1976 ◽  
Vol 54 (13) ◽  
pp. 1328-1342 ◽  
Author(s):  
R. F. Snider ◽  
R. E. Turner
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Correlation Functions ◽  
Born Approximation ◽  
Collision Cross Section ◽  
Internal State ◽  
Time Correlation ◽  
State Transitions ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation

The superoperator form of the collision cross section is evaluated within the distorted wave Born approximation. It is first verified that the obvious expansion methods give a result identical to that obtained by standard methods. Formalistically, the algebraic expansions of the transition operator and superoperator are shown to have parallel structures. The distorted wave Born approximation for the cross section also has a structure parallel to the structure of the Born approximation cross section. This is especially brought out by formulating the results in terms of time correlation functions. Certain simplifying features are found for cross sections averaged over initial and final velocity directions. These cross sections for internal state transitions are further simplified by averaging over a Maxwellian distribution of initial velocities in such a way as to obtain 'kinetic cross sections' appropriate for gas kinetic phenomena. Connection is also made with the 'constant acceleration approximation' used to estimate correlation functions in gas phase NMR.

The 44Ca(d,α)42K Reaction at 4.0 MeV

1974 ◽  
Vol 52 (9) ◽  
pp. 772-778 ◽  
Author(s):  
S. T. Lee ◽  
D. D. Long
Keyword(s):  
Excitation Function ◽  
Born Approximation ◽  
Optical Model ◽  
Angular Distributions ◽  
Model Parameters ◽  
Direct Reaction ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation

The angular distributions from the 44Ca(d,α)42K reaction were measured at Ed = 4.0 MeV in a range of angles from 40° to 160°. Based on the observation of forward peaking of the angular distributions and diminished fluctuations at 4 MeV in the excitation function, an analysis was carried out utilizing the distorted wave Born approximation. For the five strongly excited levels below 1.3 MeV, satisfactory fits were obtained using optical model parameters from the literature. The results, which were consistent with the spin assignments from other experiments, revealed no gross inadequacies of a direct reaction analysis at this energy which are not present at higher energies. For three levels in42K, the range of spins was tentatively reduced. In the case of the 1.113 MeV level, no previous assignments had been made.

Resonance recombination of spin-polarized atomic hydrogen at low temperatures

1988 ◽  
Vol 66 (5) ◽  
pp. 405-413 ◽  
Author(s):  
M. W. Reynolds ◽  
W. N. Hardy
Keyword(s):  
Cross Section ◽  
Dissociation Energy ◽  
Born Approximation ◽  
Atomic Hydrogen ◽  
Proton Exchange ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
Weakly Bound ◽  
Coupled Channels ◽  
Spin Polarized

In sufficiently large magnetic fields, the weakly bound levels of H2 acquire finite lifetimes owing to hyperfine predissociation and become manifest as scattering resonances in spin-polarized atomic hydrogen (H↓). In this work we investigate in detail the contribution to the reaction kinetics in H↓ due to the resonance, denoted [Formula: see text], arising from the predissociation of the (v,J) = (14,4) level of H2. To characterize the formation and disintegration of [Formula: see text], we calculate the predissociation as a function of both the applied magnetic field and the dissociation energy, D, of the level. Recombination occurs when [Formula: see text] is stabilized in collisions that cause transitions to lower molecular levels. For low H↓, densities, collisions with atoms of the saturated 4He vapour dominate; we calculate the cross section in the distorted wave Born approximation and also use a coupled-channels approach. At higher densities, stabilization occurs in collisions with H↓ as well; the effect of proton exchange between the atom and the molecule is derived. Previous experiments, analyzed neglecting proton exchange, are reanalyzed including this; the dissociation energy D is not as well determined by the data as was previously thought. Prospects for future experiments are discussed.

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