scholarly journals Cross sections of deuteron-induced reactions on medium-mass nuclei

2019 ◽  
Vol 14 ◽  
pp. 137
Author(s):  
A. Lagoyannis ◽  
T. Konstantinopoulos ◽  
I. Yigitoglou ◽  
A. Spyrou ◽  
G. Perdikakis ◽  
...  

Cross section measurements of deuteron-induced reactions on Ni and Ge isotopes have been carried out at energies well below the Coulomb barrier. The preliminary results are compared with statistical model calculations

2019 ◽  
Vol 10 ◽  
pp. 165
Author(s):  
C. Tsabaris ◽  
C. T. Papadopoulos ◽  
R. Vlastou ◽  
A. A. Pakou ◽  
P. A. Assimakopoulos ◽  
...  

The 7Li + 11 Β reaction has been studied in the energy range from a little below to about three times the Coulomb barrier by measuring the cross section of the 7- ray transitions in the residual nuclei produced. Statistical compound nucleus calculations have been performed in order to interpret the experimental data as well as to extract cross sections of the individual exit channels. The statistical compound nucleus theory can reproduce rather well the absolute j - ray and the various reaction channel excitation functions.


2008 ◽  
Vol 17 (10) ◽  
pp. 2349-2353 ◽  
Author(s):  
YU. E. PENIONZHKEVICH ◽  
R. KALPAKCHIEVA ◽  
A. A. KULKO ◽  
S. M. LUKYANOV ◽  
V. A. MASLOV ◽  
...  

Excitation functions for evaporation residues in the reactions 206,208 Pb (6,4 He,2n 210 Po , as well as for the transfer reactions in the interaction of 6 He and 6 Li projectiles with Au and Pt were measured at the energies near the Coulomb barrier. Studied reactions were characterized by an increase in the cross-section compared to statistical model calculations.


2020 ◽  
Vol 239 ◽  
pp. 01028
Author(s):  
R. Vlastou ◽  
A. Kalamara ◽  
G. Gkatis ◽  
A. Stamatopoulos ◽  
M. Kokkoris ◽  
...  

Cross sections for the 70,76Ge(n,2n), 72,73Ge(n,p) and 72,74Ge(n, α) reactions have been measured at the 5.5 MV tandem T11/25 Accelerator Laboratory of NCSR Demokritos, using the activation technique. Neutron beams have been produced in the ~16-20 MeV energy region, by means of the 3H(d,n)4He reaction. The maximum flux has been determined to be of the order of 105 n/cm2 s, while the flux variation of the neutron beam was monitored by using a BF3 detector. The cross section has been deduced with respect to the 27Al(n, α)24Na and 93Nb(n,2n)92mNb reference reactions. The contaminations from reactions induced on neighboring Ge isotopes and leading to the same residual nucleus, have been taken into account. After the end of the irradiations, the activity induced by the neutron beams at the targets and reference foils, has been measured by HPGe detectors. Statistical model calculations using the EMPIRE code were performed on the data measured in this work as well as on data reported in literature.


2020 ◽  
Vol 29 (05) ◽  
pp. 2050029
Author(s):  
Manjeet Singh Gautam ◽  
Sukhvinder Duhan ◽  
Rishi Pal Chahal ◽  
Hitender Khatri ◽  
Suman B. Kuhar ◽  
...  

This work emphasized the role of the projectile breakup channel by studying the complete fusion (CF) and incomplete fusion (ICF) dynamics of [Formula: see text] reactions. The theoretical calculations for the chosen reactions have been done by opting for the coupled channel approach and the energy dependent Woods–Saxon potential (EDWSP) model. The below barrier fusion enhancements of the studied reactions are reasonably addressed by the outcomes of the adopted models, which in turn can be attributed to the couplings of nuclear structure degrees of freedom of the collision partners to their relative motion. In contrast, at above barrier energies, the CF cross-section data of the chosen reactions are found to be suppressed significantly when compared with the predictions made by using the present models. Interestingly, the fusion suppression factors of the given reactions can be minimized considerably with respect to the reported value when it is analyzed within the framework of the EDWSP model. For instance, in case of [Formula: see text] ([Formula: see text] reaction, the magnitude of fusion suppression factor is minimized up to 7% (13%) relative to the reported value whereas for [Formula: see text] ([Formula: see text] reaction, the fusion suppression factor is found to be less by 7% (8%) with reference to the reported value. Such suppression effects can be correlated with the low breakup threshold of alpha breakup channel associated with the loosely bound projectile. The projectiles being weakly bound systems split into two charged fragments and either of the breakup components is absorbed by the target resulting in the reduction of incoming flux going into fusion channel. The flux lost from the CF channel appears in the form of ICF yields. For [Formula: see text], total fusion (TF) cross-sections that are sum of CF and ICF cross-sections are also analyzed in conjunction with the EDWSP model and thus reasonably explained by the model calculations. In order to identify the ICF contribution, the ratio of ICF/TF cross-section data of [Formula: see text] reaction has been examined and thus properly addressed by using the EDWSP model. The presence of ICF component in TF cross-section clearly pointed out the breakup of projectile due to its loosely bound nature prior to the Coulomb barrier. Although ICF data of other systems are not available in the literature, a similar behavior is expected for ICF and TF data for [Formula: see text] and [Formula: see text] reactions.


2020 ◽  
Vol 16 ◽  
pp. 169
Author(s):  
R. Vlastou ◽  
S. Galanopoulos ◽  
C. T. Papadopoulos ◽  
M. Kokkoris ◽  
M. Serris ◽  
...  

The72Ge(n,α)69mZn, 74Ge(n,α)71mZn, 76Ge(n,2n)75g+mGe reaction cross sections have been measured from 9.6 to 11.4 MeV and studied, along with data from litera- ture, within the frame of statistical model calculations by using the code EMPIRE-II.


1981 ◽  
Vol 34 (1) ◽  
pp. 25 ◽  
Author(s):  
HJ Gardner ◽  
LW Mitchell ◽  
SR Kennett ◽  
MR Anderson ◽  
DG Sargood

Cross sections have been measured for the reactions 53Cr(p, y)5 4Mn, 53Cr(p, n)53Mn and 53Cr(p, p/)53Cr over the proton energy range O'88-2'40 MeV. The results are compared with the predictions of statistical model, calculations with global optical model parameters, with particular reference to the role of isobaric analogue resonances. Satisfactory agreement between theory and experiment is achieved for all three reactions.


1981 ◽  
Vol 34 (1) ◽  
pp. 105 ◽  
Author(s):  
MR Anderson ◽  
SR Kennett ◽  
ME Sevior ◽  
DG Sargood

Cross sections for inelastic scattering of protons by 45SC have been measured over the energy range Ep = 1?2-2? 5 MeV for protons leading to the second, third, fourth, sixth and eighth excited states of 45SC. Statistical model calculations are' in good agreement with the data. Further statistical model cross section calculations are used in an investigation of the part played by inelastic and superelastic scattering of protons in bringing about a thermal distribution of states in 45SCin a stellar interior under the conditions of explosive silicon burning. This mechanism is found to be effective for temperatures above 4? ?x 109 K


1983 ◽  
Vol 36 (1) ◽  
pp. 1 ◽  
Author(s):  
LW Mitchell ◽  
DG Sargood

The cross section of the reaction 55Mn(p, y)56Pe has been measured in the energy range 0�80-2�04 MeV and of the reaction 55Mn(p, n)55Pe from threshold to 2� 04 MeV. Statistical model calculations reproduce the (p, n) cross section to within a factor of 1� 4, but with the (p, y) reaction they fail by a factor ;;;:2 over a significant part of the energy range. Thermonuclear reaction rates are calculated from the data for temperatures in the range (1-5) x 109 K.


2020 ◽  
Vol 227 ◽  
pp. 01008
Author(s):  
Sotirios Harissopulos ◽  
Eleni Vagena ◽  
Michail Axiotis ◽  
Artemis Spyrou ◽  
Georgios Provatas ◽  
...  

The cross sections of the 72Ge( α , γ)76Se and 1°7Ag(ρ, γ)1°8Cd reactions were measured at energies relevant to p-process nucleosynthesis. The new data, together with cross section results from our previous ( α , γ) measure-ments on 65Cu and 118Sn and other ( α , γ) cross-section data reported in lit-erature are compared with statistical model calculations performed using the latest version (1.9) of the statistical model code TALYS. In addition, the effect on these calculations of different combinations of the optical model potentials (OMPs), nuclear level densities (NLDs) and γ-ray strength functions (γSFs) entering the calculations was investigated.


1980 ◽  
Vol 33 (2) ◽  
pp. 177 ◽  
Author(s):  
FC Barker

The nonresonant part of the 7Be(p, )I)8B cross section at low energies is recalculated by means of a direct-capture potential model, using parameter values determined by fitting 7Li(n, n)7Li and 7Li(n, )I)8Li data. Standard values of the potential parameters and spectroscopic factors give values of the 7Li(n,)I) cross section that are too large. Modified values that fit the thermal-neutron capture cross section predict 7Be(p,)I) cross sections that are much less than the experimental values. Also, shell model calculations predict resonant 7Be(p,)I) cross sections that are smaller than the experimental values. It is suggested that the accepted experimental values of the 7Be(p, )I) cross section may be too large, perhaps due partly to an overlarge accepted value for the 7Li(d, p)8Li cross section, which has been used for normalization purposes. A decrease in the 7Be(p,)I) cross section would reduce the calculated detection rate of solar neutrinos and lessen the discrepancy with the measured value.


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