Excitation Functions Of Reactions Research Articles

Determination of excitation function for alpha induced reactions on 237Np and 238Pu

The excitation function of the alpha particle-induced reactions on 237Np and 238Pu has been determined for the incident alpha energies ranging from threshold to 50 MeV using TALYS1.95 nuclear reaction code. In this study, the excitation function of (α,xn) reactions on 237Np and 238Pu has been determined by invoking the Jeukenne–Lejeune–Mahaux–Bruyeres Optical model potential. The microscopic nuclear level density from Hilaire’s combinatorial table is used to calculate the nuclear level density. Also, the excitation function has been evaluated by using the alpha potential of Watanabe folding approach with Koning–Delaroche spherical optical model potential and McFadden–Satchler potential. Furthermore, all the calculated cross-sections have been compared with the experimental results taken from EXFOR and the available evaluated cross-sections from TENDL2019 nuclear data library. The calculated cross sections using Jeukenne–Lejeune–Mahaux–Bruyeres Optical model potential together with microscopic nuclear level density from Hilaire’s combinatorial table incorporating the Skyrme–Hartree–Fock–Bogoliubov calculation results in good correspondence with the experimental values from EXFOR.

Excitation functions of proton-induced nuclear reactions on natCaCO3 up to 60 MeV

47Sc could be used in SPECT imaging and is also suitable for targeted therapy of small tumours. Application of 47Sc is quite promising as theranostic with its diagnostic pair 44Sc or 43Sc. Excitation functions for the production of 47Sc and its accompanying impurities through proton bombardment of natural calcium carbonate (natCaCO3) targets were experimentally evaluated and compared with both previous measurements and TALYS predictions. The integral production yields of 47Sc, as well as the main impurities 44m,46,48Sc, were calculated. The consistency of the results with available experimental data was verified for each reaction. The target yield was determined using the measured activity of the produced radionuclides.

Investigation of the Excitation Functions of Proton-Induced Reactions on Natural Gadolinium Using the Nuclear Interaction Codes TALYS 1.96 and EMPIRE 3.2

Investigation of the Excitation Functions of Proton-Induced Reactions on Natural Gadolinium Using the Nuclear Interaction Codes TALYS 1.96 and EMPIRE 3.2

Exploring the possibilities of sub barrier fusion enhancement in fusion reactions induced by 28Si on 64Ni, 96Zr, 100Mo and 154Sm at energies around Coulomb barrier

The fusion excitation functions of reactions induced by 28Si on 64Ni, 96Zr, 100Mo and 154Sm targets at around Coulomb barrier energies have been analysed theoretically within coupled channel approach. Here we have examined the sensitivity of fusion cross section at sub-barrier energies towards coupling of inelastic excitations of fusing partners and positive Q-value neutron transfer (PQNT) channels. Along with the transfer channel, the influence of variation in deformation of fusing nuclei after transfer and of nuclear structure of fusing nuclei has also been considered. With a view to investigate the influence of nuclear structure here we have taken targets with different structural properties. It is found that coupling of neutron transfer channels produced a significant enhancement in sub-barrier fusion for the systems where one of the interacting nuclei is spherical or less deformed and no influence of transfer coupling has been observed for the system where both the participating nuclei are deformed.

Consistent assessment of neutron-induced activation of 93Nb

A concurrent assessment of all measured excitation functions for various reactions induced by neutrons on 93Nb, in addition to the results of TENDL-2021 and default parameters in TALYS-1.96, is given in this work. We use consistent parameter sets that were formerly obtained or validated by the analysis of other independent data, while no empirical rescaling factors of γ and/or neutron widths have been used. The correlation between the measured error bars of the primary data providing the consistent input parameters and the final uncertainty bands of the calculated results have been pointed out. At the same time, a proper account in this work of all available data for competitive reaction channels prevented compensation effects of less accurate model parameters. Remaining questions and the need for additional measurements are emphasized.

Analysis of elastic scattering angular distributions and fusion excitation functions of reactions induced by 9Be on 27Al, 28Si, 144Sm and 208Pb targets at near barrier energies

The elastic scattering angular distributions and the fusion excitation function data for the reactions induced by the loosely bound projectile 9Be on [Formula: see text]Al, [Formula: see text]Si, [Formula: see text]Sm and [Formula: see text]Pb targets at near and above barrier energies have been analyzed with a motive to investigate the importance of breakup couplings within the framework of continuum discretized coupled channels approach. It is found that at energies much higher than Coulomb barrier, the breakup effects are insignificant for light targets while for heavy targets, the breakup effects play a dominant role at these energies. But at energies comparable to the barrier height, the role of breakup becomes crucial for light mass targets also.

Excitation functions of neutron-induced threshold reactions in Au, Bi, Ta measured using 30–94 MeV quasi mono-energetic neutron sources

Activation measurements of neutron-induced threshold reactions were studied employing 7Li(p,n) quasi mono-energetic neutron sources in the neutron energy range of 30–94 MeV, where scarce experimental and evaluated data exist. A novel iterative neutron background subtraction approach is presented for the first time and its successful application is demonstrated on the analysis of the excitation functions of (n,xn) reactions in Au, Bi and Ta with x up to 10. Some of them are on the High Priority Nuclear Data Request List (HPRL). A comprehensive comparison of the measured data with theoretical predictions using the TALYS code is presented. While the calculated cross-sections agree with the measurements for lower-threshold reactions, severe discrepancies are observed for higher (n,xn) reactions for any of the TALYS model parameters.

Analysis of excitation functions of (p,n) reactions for the stable isotopes of zinc and copper up to 40 MeV

Analysis of excitation functions of (p,n) reactions for the stable isotopes of zinc and copper up to 40 MeV

Bayesian evaluation of residual production cross sections in proton-induced nuclear spallation reactions

Residual production cross sections in spallation reactions are key data for nuclear physics and related applications. Spallation reactions are very complex due to the wide range of incident energies and abundant fragments involved. Therefore, it is challenging to obtain accurate and complete energy-dependent residual cross sections. With the guidance of a simplified EPAX formula (sEPAX), the Bayesian neural network (BNN) technique is applied to form a new machine learning model (BNN + sEPAX) for predicting fragment cross sections in proton-induced nuclear spallation reactions. Three types of sample dataset for measured residual production cross sections in proton-induced nuclear spallation reactions are made, i.e. D1 consists of isotopic cross sections in reactions below 1 GeV/u, D2 consists of fragments excitation functions of reactions up to 2.6 GeV/u, and D3 is a hybrid of D1 and D2. With the constructed BNN and BNN + sEPAX models, the isotopic and mass cross section distributions are compared for the 356 MeV/u 40Ca + p and 1 GeV/u 136Xe + p reactions, and fragment excitation functions in 40Ca + p, 56Fe + p, 138Ba + p and 197Au + p reactions. It is found that the BNN model needs sufficient information to achieve good extrapolations, while the BNN + sEPAX model performs better extrapolations based on less information due to the physical guidance of the sEPAX formulas. It is suggested that the BNN + sEPAX model provides a new approach to predict the energy-dependent residual production cross sections produced in proton-induced nuclear spallation reactions of incident energies from tens of MeV/u up to several GeV/u.

An overview of activation cross-section measurements of some neutron and charged-particle induced reactions in Bangladesh

Abstract Over the last several decades, our research group has been working on nuclear data measurements using a J-25 Neutron Generator, a TRIGA Mark II Research Reactor and a Tandem Accelerator at Savar, as well as an Am/Be neutron source at Rajshahi. The spectrum of fast neutrons having energies from 0.5 to 20 MeV in the core of the TRIGA reactor as well as from 1.5 to 11 MeV of the Am/Be source was well characterized for validation of evaluated data of neutron threshold reactions. Spectrum-averaged cross sections were determined by integral measurements. The integral values measured at both the reactor and the Am/Be source were compared with the integrated data deduced from measured and evaluated excitation functions of some nuclear reactions given in some data libraries. As example, the details on the integral and integrated cross sections of the 64Zn(n,p)64Cu and 60Ni(n,p)60Co reactions are discussed. In both cases, integral test shows that further improvement of the evaluated excitation function reported in data libraries is needed. The use of a newly developed facility at the 3 MV Tandem Accelerator in measurement of proton induced reaction cross sections in the energy region below 5 MeV is outlined, and new results on the 64Ni(p,n)64Cu and natNi(p,x)61Cu processes below 3 MeV are discussed.

Excitation functions of proton-induced reactions on natW target for rhenium isotope production

The proton-induced reaction cross-sections on natural tungsten within the proton energy range of 12.50 ± 0.79 MeV to 44.08 ± 0.33 MeV are determined by using the stacked-foil activation method and offline γ-ray spectrometry at the MC50 cyclotron of the Korea Institute of Radiological and Medical Science. The proton beam intensity is determined by using the natCu(p,xn)62Zn and natCu(p,xn)65Zn monitor reactions. The residual nuclide activities are measured using an HPGe γ-ray detector. The experimental results in this work contains 63 individual measured points for seven identified nuclides 181;182m,g;183;184m,g;186Re via the natW(p,xn) reactions. In addition, the thick target yields are determined for the 181;182m,g;183;184m,g;186Re products produced from the natW(p,xn) reactions. The present data are compared with literature data and the theoretical predictions from the TALYS-1.9 code and the TENDL-2019 library.

Excitation functions of proton-induced nuclear reactions on ^{86}Sr, with particular emphasis on the formation of isomeric states in ^{86}Y and ^{85}Y

Cross sections of proton-induced nuclear reactions on enriched ^{mathrm {86}}Sr target were measured by the activation technique up to proton energies of 44 MeV. The isomeric cross-section ratios for ^{mathrm {86m,g}}Y and ^{mathrm {85m,g}}Y as a function of projectile energy were deduced from their measured data. The present experimental data for the nuclear reaction products, namely ^{mathrm {86m}}Y, ^{mathrm {86g+xm}}Y, ^{mathrm {85m}}Y, ^{mathrm {85g}}Y, ^{mathrm {84}}Rb and ^{mathrm {83}}Rb were compared with the results of nuclear model calculations using the code TALYS, which combines the statistical, precompound, and direct interactions. In general, the experimental cross-section data as well as the isomeric cross-section ratios are reproduced well by the model calculations, provided the input model parameters are properly chosen and the level structure of the product nucleus is thoughtfully considered. The quality of the agreement between experimental data and model calculations was numerically quantified. For products formed via emission of a light complex particle as well as multi-nucleons (e.g., alpha and 2p2n), the contribution of the latter process starts increasing when its energy threshold is crossed.

Excitation functions of natNi(p, x) reactions in the energy range of 75–100 MeV

Stacked-foil activation technique and high-resolution gamma spectrometry were used to investigate new excitation functions of proton-induced nuclear reactions on natNi targets in the energy range of 75–100 MeV. The stack foils were irradiated with 100 MeV protons at the separated-sector cyclotron of the Institute of Modern Physics, Chinese Academy of Sciences, China. The proton intensity for each nickel foil was determined using the natNi(p, x)57Ni monitor reaction. The cross-sections of the natNi(p, x)56Ni, 55,57,58Co, and 54Mn reactions were calculated and compared with the existing literature data presented in the Experimental Nuclear Reaction Data (EXFOR). Furthermore, evaluated nuclear data of the PADF-2007, ENDF/B-VIII.0, and JENDL-4.0/HE libraries as well as theoretical calculations of the TALYS code were used. Overall, our experimental data agree with the majority of the literature data. The results of TALYS code as well as the ENDF/B-VIII.0 and JENDL-4.0/HE libraries could reproduce most of the experimental trend, whereas the results of PADF-2007 library could not do so. The new experimental results provide cross-sections for proton-induced natNi reactions in the energy range of 75–100 MeV and could serve as a technical assistance for radionuclide production and radiation safety practices.

Medical radiaosotopes production: Activation cross-sections of 52Mn by the alpha-induced reaction on natural vanadium (V)

Excitation functions for α-induced reactions on natural vanadium were calculated in the energy range up to 50 MeV. The production cross sections of 52Mn will be compared to some previously published results and the TALYS (TENDL 2019) code calculations. The integral yield of 52Mn is derived from the calculated cross-sections and compared with those from other production routes.

Exploring the effects of breakup couplings for weakly bound projectile 9Be on various targets at around barrier energies

Here, the fusion excitation functions of reactions induced by 9Be on various heavy mass targets, 144Sm, 169Tm, 181Ta, 186W, 187Re, 197Au and 208Pb, at around barrier energies have been studied within the framework of the Continuum Discretized Coupled Channel (CDCC) approach. The inconsistency in the definitions of theoretical and experimental fusion cross section is properly accounted for which results in a fair agreement between data and predictions at near and above barrier energies for all the targets except Tungsten. The difference between the measured and the calculated fusion cross section is found to be independent of the targets.

ESTIMATION OF GROSS-STRUCTURE PARAMETERS OF GIANT DIPOLE RESONANCE: 2. EXPERIMENTAL TESTING

Experimental testing of a novel technique for determination of width and maximum of excitation function of a photonuclear reaction with dominant giant dipole resonance is conducted. The method is based on measurement of normalized reaction yield in a thin target, overlapping entirely a flux of X-rays and on processing of data obtained with the use of a developed analytical model. For the checking of method, the nickel and molybdenum foils of natural isotopic composition were activated by bremsstrahlung radiation at four energies of the electron beam in the range 40…95 MeV. The obtained parameters of cross-section of the reference reactions 58Ni(γ,n)57Ni and 100Mo(γ,n)99Mo are in good agreement with those presented in the available databases.

Theoretical Calculations of the Cross-sections for (n,α) and (n,xα) reactions on the Structural Material for Fusion Reactor 46-50Ti

The biggest problem of structural materials for fusion reactor is the damage caused by the fusion product neutrons to the structural material. If this problem is overcomed, an important milestone will be left behind in fusion energy. One of the important problems of the structural material is that nuclei forming the structural material interacting with fusion neutrons are transmuted to stable or radioactive nuclei via (n, x) (x; alpha, proton, gamma etc.) reactions. In particular, the concentration of helium gas in the structural material increases through deuteron- tritium (D-T) and (n, α) reactions, and this increase significantly changes the microstructure and the properties of the structural materials. Therefore, in this study, the effects of the different nuclear level density models on the excitation functions of the (n, α) reactions on 46-50Ti isotopes, an attractive candidate for the structural material for fusion reactors, have been investigated for the first time. Also, the differential cross-sections with respect to alpha energy for the emission of alpha particles of the 46-50Ti (n, xα) reactions have been investigated at 14.1 MeV incident neutron energy. The calculations are performed using the two-component exciton model in the TALYS 1.9 code, and the results are compared with available experimental data. The results of this study will contribute to nuclear database as required for improving, design and operations of the important facilities as ITER (International Thermonuclear Experimental Reactor), DEMO (The demonstration power plant) and ENS (European Nuclear Society).

Excitation functions of some deuteron-induced nuclear reactions on Al

Abstract Excitation functions of the reactions 27Al(d,αp)24Na, 27Al(d,2p)27Mg and 27Al(d,p)28Al were measured by the activation technique up to deuteron energies of 37 MeV. The available experimental databases of the reaction products 27Mg and 28Al were extended and compared with the nuclear model calculations based on the code TALYS-1.8. Our measured data are reproduced well by the model calculations after adjustment of a few free input parameters. The cross-section ratio of the (d,αp) to (d,2p) process as a function of projectile energy was deduced from the measured data, and the result is interpreted in terms of competition between a proton and an α-particle emission.

Excitation functions for Rh, Ru and Tc radionuclides obtained by proton irradiation of natRu up to 33.6 MeV

Excitation functions for reactions induced by protons up to 33.6 MeV on natural ruthenium targets (Ru) were experimentally obtained using the activation method through stacked foil irradiations. The cross-sections for the production of the radionuclides 94g,95m,95g,96m,96g,99mTc, 95,97,103Ru and 99m,99g,100g,101m,101g,102m,102gRh were derived from high resolution γ-ray spectrometry without any chemical processing. Comparison with the few earlier published experimental data and with values predicted by the theoretical code TALYS 1.6 (as available in the on-line library TENDL-2019) are discussed. Thick target yields calculated from fits to our experimental excitation curves are discussed.

Investigating the excitation functions of the neutron-induced reactions leading to the radioactive products on natural titanium isotopes

In this study, the excitation functions of some (n, x) reactions leading to the radioisotope products on natural titanium isotopes, which is an important material for fusion technology, are calculated by using the ALICE/ASH and TALYS 1.95 codes. Besides, the effects of the phenomenological and the microscopic nuclear level density models on these excitation functions are investigated by using the two-component exciton and geometry dependent hybrid models. The obtained results for the considered reactions in this study are compared with the available experimental and ENDF/B-VIII data, and the suitable nuclear level density model is determined for each reaction. According to the results, the phenomenological nuclear level density models are generally in good agreement with experimental data, except for 48Ti(n,d) and 50Ti(n,γ) reactions. Also, the results of this study can be used to predetermine radiotoxicity in the structural material for a fusion reactor.