Cross Section Database Research Articles

Investigation of the Nuclear Cross-Sections for Proton Capture Reactionsin the Star Formation Process of the Galaxies

Understanding the CNO cycle and the proton-proton (p-p) chain is essential for comprehending the development of main sequence stars in the initial stages of spiral and elliptical galaxy formation. This study investigates two nuclear reactions that occur in spiral galaxies and elliptical galaxies. Using theoretical computer software (e.g. OriginPro. software program), we summarized the excitation functions to analyze the (p,γ) interaction cross sections of 7Be(p,γ)8B, 12C(p,γ)13N, 14N(p,γ)15O, and 15N(p, γ)12C. In the p-p series and CNO cycle with energy up to 8 MeV. In this work, we compared the theoretical values from the ENDF/B-VII library with the estimated database of nuclear fusion cross sections in hydrogen-burning stellar objects from CSC-GM and TALYS. For these nuclei, cross sections can be calculated at low energies within the pp chain and CNO cycle. Therefore, we were able to calculate only four finite elements in the CNO cycle and the pp series.

Determination of mass attenuation coefficient for common prosthetic materials utilizing Monte Carlo simulation, theoretical analysis, and XCOM software

Abstract The accurate calculation of radiation doses in radiotherapy necessitates precise knowledge of the mass attenuation coefficients ( μ m ) of prosthetic materials. Thus, this study aims to determine the μ m of widely used prosthetic materials through theoretical methods, Monte Carlo (MC) simulation, and the XCOM photon cross-section database for the first time. Calculations were performed for the following medical sources: Pd-103, I-125, Cs -131, Tc-99m, Ba-133, Ir-192, Au-198, Cs-137, Ra-226 and Co-60 with a range of energies between 10 keV and 2 MeV. Outcomes reveal that in all three datasets increasing the energy reduces the μ m values for all provided materials. For instance, this value for MMA and PEG and MCNPX simulations, theoretical calculation, XCOM evaluation varies from 0.41911 to 0.09006 cm2.g−1, 0.39194 to 0.08583 cm2.g−1, 0.39790 to 0.08715 cm2.g−1, and 0.45099 to 0.09029 cm2.g−1, 0.42214 to 0.09050 cm2.g−1, 0.40040 to 0.08090 cm2.g-,1 respectively. Furthermore, for high density prosthetic materials like Steel, Titania, and Zinc oxide, μ m is higher specifically at low energy regions compared to low density prosthetic materials, while increasing the energy from 0.021 to 1.25 MeV, a different scenario is recorded. Moreover, MCNPX results exhibit higher deviations specifically in high energy regions compared to other approaches. However, this approach remains as accurate for prosthetic attenuation evaluation. The results of this study present a detailed classification of a wide range of prosthetic materials in terms of their applications and energy levels, serving as a significant reference for future research.

Machine learning study of universal electronic stopping cross-sections of ions in matter

Accurate electronic stopping cross-section (ESCS) database of ions in matter is crucial for precise simulation of radiation damage. Based on the experimental-cleaned database of SRIM, binary theory and unitary convolution approximation as well as the descriptor pool extracted from these models, we developed a universal machine learning ESCS database using the least absolute shrinkage and selection operator (LASSO) algorithm. This method allows for predictions for ion-target combinations with atomic numbers from 1 to 92, within the energy range from 1 keV/u to 1 GeV/u, addressing the limitations of machine learning on training dataset. The database exhibits remarkable accuracy in predicting ESCS and ion depth distribution/range, along with robust reciprocity performance. Key descriptors are also determined, which closely mimic the Lindhard-Scharff-Schiott and Bohr-Bethe-Bloch formulations, achieved through precise adjustments of the exponent of individual elements. The proposed universal ESCS database surpasses the accuracy of existing databases, supporting related applications across a wide range of energies and systems.

Activation cross-sections of proton-induced nuclear reactions on natural zinc in the energy range of 4–30 MeV

In the present work, the excitation functions for the proton-induced nuclear reactions on natural zinc were measured in the energy range of 4–30 MeV using the well-established stacked-foil activation procedure. The activation products were measured based on their characteristic gamma lines using HPGe γ-ray spectrometry. The radioactivities determined were used for the calculation of cross-sections of the radionuclides of interest, i.e., 61Cu, 62,65,69mZn, 57Co and 66,67,68Ga. The cross-sections have also been compared with the available literature data and the theoretical prediction of the TALYS code via its latest TENDL-2023 library as well as the prediction of EMPIRE-3.2.2 model code. The results show a reasonable agreement when compared with the available literature data. This work, however, shows that the theoretical data extracted from the TENDL-2023 library and EMPIRE-3.2.2 default calculation significantly underestimate the experimental cross-sections of 57Co nuclide while they overestimate those of 69mZn. The present result has potential applications to improve the predicting capability of the model codes as well as to serve as additional data for the nuclear reaction cross-section database.

Measurement of fast neutron induced (n,γ) reaction cross-section of 68Zn, 96Zr, 121Sb and 123Sb in the energy range of 1 to 2 MeV

The (n,γ) reaction cross-section for the elements 68Zn, 96Zr, 121Sb and 123Sb, present in the reactor structural/shielding materials, was measured by neutron activation technique in the neutron energy region of 1–2 MeV as very limited data is available in this energy range. Further, the neutron spectrum peaks in this energy region for the fast breeder reactors and proposed accelerator driven sub-critical systems. The natural strontium (natSr) element was used as a neutron flux monitor by considering effective combined reaction cross-section for 86Sr(n,γ)87Srm and 87Sr(n,n′)87Srm reactions. The pellets of mixture of sample and monitor were irradiated by a quasi-mono energetic fast neutron beam, generated by 7Li(p,n)7Be reaction at FOTIA, Bhabha Atomic Research Centre, Mumbai, India. The activity of activation products was measured by off-line gamma-ray spectrometry using High Purity Germanium Detector (HPGe). The present data with improved uncertainty and covariance analysis enhance the cross-section data base for better constraining the evaluated data and theoretical models. The theoretical (n,γ) reaction cross-sections were calculated using TALYS 1.96, which could reasonably explain the present data with the Fermi gas level density prescription.

Data and modeling sensitivity analysis for molten salt fast reactor benchmark – Static calculations

The Molten Salt Reactor (MSR) idea is increasingly being recognized in the nuclear field due to its potential safety, sustainability, and economic efficiency advantages. The Molten Salt Fast Reactor (MSFR) benchmark, introduced in 2019, highlighted variations in results tied to different neutron cross-section libraries. This study investigates the impact of utilizing the ENDF/B-VIII.0 and JEFF-3.3 cross-section libraries for MSFR benchmark assessment compared to the ENDF/B-VII.1 database. Monte Carlo based open source code OpenMC is used for the analyses. Rigorous sensitivity analyses assess the influence of individual components, including the cross-section database, resonance elastic scattering, and Thermal Scattering Law (TSL). Beyond the criticality assessments, parameters such as delayed neutron fraction, temperature coefficient of reactivity, and neutron spectrum are compared for different cross-section libraries. Our analyses reveal that incorporating new evaluations for 233U (n,γ) and fission cross-sections in ENDF/B-VIII.0 significantly alters criticality results, i.e., more than 1700 pcm difference is seen between libraries. Similarly, critical concentration using ENDF/B-VII.1 and JEFF-3.3 is over-predicted by approximately 3%. The variations in Thermal Scattering Law (TSL) files do not yield substantial differences in outcomes due to the fast spectrum of the reactor. In some cases, the treatment of resonance elastic scattering leads to reactivity differences greater than 50 pcm. The benchmark compares 233U-started and Minor Actinide (MA)-started core. From the reactor physics point of view, the MA-started core leads to a 29% higher (n, γ) reaction rate than the 233U-started core. A 3–4% smaller value of thermal reactivity coefficient is obtained using the ENDF/B-VIII.0 library compared to the ENDF/B-VII.1 value. Using the ENDF/B-VIII.0 for the MSFR benchmark signifies using newer and better data for the GEN-IV reactors neutron physics calculations.

Development of a cyclic ion mobility spectrometry-mass spectrometry-based collision cross-section database of permethylated human milk oligosaccharides.

Human milk oligosaccharides (HMOs) are an important class of biomolecules responsible for the healthy development of the brain-gut axis of infants. Unfortunately, their accurate characterization is largely precluded due to a variety of reasons - there are over 200 possible HMO structures whereas only 10s of these are available as authentic analytical standards. Furthermore, their isomeric heterogeneity stemming from their many possible glycosidic linkage positions and corresponding α/β anomericities further complicates their analyses. While liquid chromatography coupled to tandem mass spectrometry remains the gold standard for HMO analyses, it often times cannot resolve all possible isomeric species and thus warrants the development of other orthogonal approaches. High-resolution ion mobility spectrometry coupled to mass spectrometry has emerged as a rapid alternative to condensed-phase separations but largely has remained limited to qualitative information related to the resolution of isomers. In this work, we have assessed the use of permethylation to improve both the resolution and sensitivity of HMO analyses with cyclic ion mobility separations coupled with mass spectrometry. In addition to this, we have developed the first-ever high-resolution collision cross-section database for permethylated HMOs using our previously established calibration protocol. We envision that this internal reference database generated from high-resolution cyclic ion mobility spectrometry-mass spectrometry will greatly aid in the accurate characterization of HMOs and provide a valuable, orthogonal, approach to existing liquid chromatography-tandem mass spectrometry-based methods.

TYtool: A software application for yield and target power optimization in charged particle induced radionuclide production

A software application useful for optimization and maximizing radionuclide production without exceeding the power limits of the target material or holder has been developed. The software (TYtool) can be used for target optimization including yield calculations vs time, thickness, and incident energy, W/mm through the target, and automated target thickness optimization with the Makkonen-Craig & Helariutta − or the novel Yield/Wapproach. TYtool also facilitates graphical representation of many basic plots such as cross section, mass stopping power, activity output, projected range and it is useful for many different particles, reactions, radionuclides via the default cross section data base or the import function for cross section and mass stopping power. The software is available for free at: https://gitlab.com/NM_Karolinska_Solna/TYtool.

Analysis of the atomic ratio of H and Zr effect on the neutronics parameters of ZrH moderated space nuclear reactor

Zirconium hydride (ZrH) is an ideal moderator for space nuclear reactors due to its exceptional properties, including high hydrogen content, small neutron absorption cross section, and high operating temperature. The primary goal of this study is to examine how the atomic ratio of H to Zr (H/Zr ratio) influences the neutronics parameters of a ZrH moderated space nuclear reactor, with a focus on establishing a reliable reference for ensuring the optimal safety and minimization of such reactors. The neutronics calculation based on the ZrH moderated space nuclear reactor named Topaz-II is performed using the Reactor Monte Carlo code (RMC code) with the ENDF/VII cross-section database. The effects of the H/Zr ratio were studied with a particular focus on the initial keff, the burnup, the temperature reactivity coefficient and the criticality safety. The results show that with the increase of the H/Zr ratio, the initial keff increases while the drums’ worth decreases. The Moderator Temperature Coefficient (MTC) is a positive value that rises as the H/Zr ratio increases. In the dropping accidents, the reactor full of voids with seawater is more serious, and the introduced reactivity decreases with the increase of the H/Zr ratio.

Extension of evaluated cross section database for charged particle monitor reactions

The evaluation and deduction of recommended cross section values allowing extension of the database to monitor energy and intensity parameters of charged particle beams is presented. Included are 53 charged particle (p, d, 3He, 4He) induced reactions on suited C, Al, Ti, Fe, Ni, Cu, Nb and Au targets. The new data allow more systematic simultaneous use of multiple reactions on the same target and promote the backings of electrodeposited and sedimented targets as monitoring aids. Where possible the energy range is extended to above 100 MeV. Integral yield curves over the studied energy range are derived and compared to experimentally measured yields at specific energy points. A comparison with the theoretical excitation curve prediction of the TALYS-code as available in the TENDL 2021–2023 libraries is shown.

The Astrochemistry Low-energy Electron Cross-Section (ALeCS) database

Context. Electron–molecule interaction is a fundamental process in radiation-driven chemistry in space, from the interstellar medium to comets. Therefore, knowledge of interaction cross sections is key. There have been a plethora of both theoretical and experimental studies of total ionization cross sections spanning from diatomics to complex organics. However, the data are often spread over many sources or are not public or readily available. Aims. We introduce the Astrochemistry Low-energy Electron cross-section (ALeCS) database. This is a public database for electron interaction cross sections and ionization rates for molecules of astrochemical interest. In particular, we present here the first data release, comprising total ionization cross sections and ionization rates for over 200 neutral molecules. Methods. We include optimized geometries and molecular orbital energies at various levels of quantum chemistry theory. Furthermore, for a subset of the molecules, we have calculated ionization potentials. We computed the total ionization cross sections using the binary-encounter Bethe model and screening-corrected additivity rule, and we computed ionization rates and reaction network coefficients for molecular cloud environments. Results. We present the cross sections and reaction rates for >200 neutral molecules ranging from diatomics to complex organics, with the largest being C14H10. We find that the screening-corrected additivity rule cross sections generally significantly overestimate experimental total ionization cross sections. We demonstrate that our binary-encounter Bethe cross sections agree well with experimental data. We show that the ionization rates scale roughly linearly with the number of constituent atoms in the molecule. Conclusions. We introduce and describe the public ALeCS database. For the initial release, we include total ionization cross sections for >200 neutral molecules and several cations and anions calculated with different levels of quantum chemistry theory, the chemical reaction rates for the ionization, and network files in the formats of the two most popular astrochemical networks: the Kinetic Database for Astrochemistry, and UMIST. The database will be continuously updated for more molecules and interactions.

Extension of recommended cross section database for production of therapeutic isotopes

Radionuclide-based diagnostics and therapy require proper selection of production nuclear reaction based on knowledge of the production excitation functions and the achievable yields completed with data on the formation of possible impurities. In the present work the existing IAEA recommended cross section data database for production of therapeutic isotopes is extended to production of the 47Sc,47Ca(47Sc), 58mCo, 71As(71Ge), 71Ge, 77Br, 77Kr(77Br), 80mBr, 103Pd, 103Pd(103mRh), 103Ru(103mRh), 105Rh, 117mSn, 119Sb, 119mTe(119Sb), 134Ce, 135La, 149gTb, 161Tb, 165Er, 165Tm(165Er), 167Tm, 197mHg, 197gHg, 198gAu, and 230Pa(230U) radioisotopes. Nearly 60 nuclear reactions are presented and discussed. The new recommended cross-section data and their uncertainties for the production of these 21 radionuclides will be available on the Web page of the IAEA Nuclear Data Section at https://nds.iaea.org/radionuclides and also at the IAEA medical portal https://nds.iaea.org/medportal.

Optimisation of the Tripathi model using a nuclear reaction cross-section database

Nuclear reaction cross-sections are an essential ingredient to reliable deterministic and stochastic radiation transport codes used for radiation protection in space and heavy-ion therapy applications. A recent study compared the existing literature data compiled within the open-access GSI-ESA-NASA cross-section database to the models implemented in the transport codes most commonly used for radiation protection in space and heavy-ion therapy applications. The outcome of the comparison was that none of the models fit well the experimental data for all projectile-target systems at all energy ranges. Therefore, the literature data were exploited to optimise the Tripathi–Cucinotta–Wilson model as reported in this work. This model is used as default in FLUKA, TRiP, and SpaceTRiP, it is part of the hybrid-Kurotama (HK) model used in particle and heavy ion transport code (PHITS), and it is implemented in Geant4. The consequences of using the proposed Tripathi–Cucinotta–Wilson optimisation in the HK model are also analysed.

Radiation attenuation of SiO2–MgO glass system for shielding applications

Silicate glasses are an essential material in many industries due to their unique properties. In this study, we aim to investigate the potential of (100-x) SiO2-xMgO (x = 5, 20, 35, and 55 mol%) glass system to use for medical and nuclear applications. The silicate oxide is reduced and the MgO is added accordingly with different concentrations of 5, 20, 35, and 55 mol%, with sample codes of SM1, SM2, SM3, and SM4, respectively. The goal of such change is to develop glasses with optimum radiation attenuation properties. The Mass attenuation coefficient (MAC) of the glasses, for different photon energies, is calculated using the Geant4 Monte Carlo simulations and the XCOM photon cross section database. The simulation results provide vital data on the shielding effectiveness of the glass compositions against photon radiation. The obtained findings showed that the radiation attenuation properties can be tailored by adjusting the relative concentrations of the constituting glass oxides, such as SiO2 and MgO. For example, the best shielding performance is observed for the SM1 sample, with the highest concentration of SiO2, among the studied glasses. Furthermore, the shielding performance of the studied glasses is compared with some famous materials previously considered in recent publications. Therefore, the present glasses show promising shielding performance, with high effective and low-cost, for potential use in real radiation sources for experimental validation.

The development of nuclear reactor three-dimensional neutronic thermal–hydraulic coupling code: CorTAF-2.0

Numerical reactor technology is the development direction of advanced nuclear energy system simulation, which has the ability of high-fidelity multi-physical field coupling calculation. The thermal–hydraulic and neutron physics fields in reactor core exhibit strong feedback relationships. Establishing the neutronic thermal–hydraulic coupling calculation model of the whole core “pin-by-pin” is the key technology for the development of numerical reactors. In this study, the neutron diffusion analysis model and cross-section database have been developed based on the open source CFD platform OpenFOAM. The three-dimensional neutron diffusion analysis model based on the finite volume method has been validated by benchmark problems. By integrating the neutron diffusion analysis model and cross-section database into nuclear reactor core three-dimensional thermal–hydraulic characteristics analysis code CorTAF, the strongly coupled neutronic thermal–hydraulic coupling analysis code CorTAF-2.0 has been developed. The neutronic thermal–hydraulic coupling phenomena in the full core of AP1000 have been simulated using CorTAF-2.0, yielding the sub-channel level parameters distribution of the whole core. This work offers valuable references for reactor full-core neutronic thermal–hydraulic coupling analysis.

Copper radionuclides for theranostic applications: towards standardisation of their nuclear data. A mini-review.

Copper has several clinically relevant radioisotopes and versatile coordination chemistry, allowing attachment of its radionuclides to biological molecules. This characteristic makes it suitable for applications in molecular imaging or radionuclide targeted therapy. Of particular interest in nuclear medicine today is the theranostic approach. This brief review considers five radionuclides of copper. These are Cu-60, Cu-61, Cu-62, Cu-64, and Cu-67. The first four are positron emitters for imaging, and the last one Cu-67 is a β--emitting radionuclide suitable for targeted therapy. The emphasis here is on theory-aided evaluation of available experimental data with a view to establishing standardised cross-section database for production of the relevant radionuclide in high purity. Evaluated cross section data of the positron emitters have been already extensively reported; so here they are only briefly reviewed. More attention is given to the data of the 68Zn(p,2p)67Cu intermediate energy reaction which is rather commonly used for production of 67Cu.

Neutronic and burn up analysis of VVER 1000 benchmark using EXCEL and TRIHEX-FA code system

Benchmarking and validation of the neutronic codes is an important aspect of the reactor design. This paper presents VVER-1000 X2 Benchmark steady state core physics analysis carried out using the lattice level burn-up code, EXCEL and core physics analysis using multi-group diffusion code, TRIHEXFA developed at BARC. These codes have been augmented with new features for modeling of LWR Cores. The VVER-1000 X2 Benchmark with modern fuel assembly (FA) design is a comprehensive benchmark proposed for validating and verifying package of codes and data libraries for reactor physics calculations of LWRs, which includes fuel assembly modeling, generation of homogenized cross section data base for all envisaged core conditions, and reactor core modeling. The trends of k∞ (k-inf) values as a function of various parametric variations and as a function of burn-up for all the fuel assemblies considered in benchmark are analyzed in detail and the deviations have been estimated.The VVER-1000 core follow-up simulations are done by using core diffusion code TRIHEXFA using the few group data generated by EXCEL code. Important core physical characteristics like critical soluble boron, 2-D radial power distribution, axial power distribution, radial peaking factors and volumetric power peaking factors, FA burn-up values obtained from the TRIHEXFA simulations are compared with the experimental core follow up data. All these parameters are found to be reasonably in good agreement with the values provided in benchmark.

AllCCS2: Curation of Ion Mobility Collision Cross-Section Atlas for Small Molecules Using Comprehensive Molecular Representations.

The development of ion mobility-mass spectrometry (IM-MS) has revolutionized the analysis of small molecules, such as metabolomics, lipidomics, and exposome studies. The curation of comprehensive reference collision cross-section (CCS) databases plays a pivotal role in the successful application of IM-MS for small-molecule analysis. In this study, we presented AllCCS2, an enhanced version of AllCCS, designed for the universal prediction of the ion mobility CCS values of small molecules. AllCCS2 incorporated newly available experimental CCS data, including 10,384 records and 7713 unified values, as training data. By leveraging a neural network trained on diverse molecular representations encompassing mass spectrometry features, molecular descriptors, and graph features extracted using a graph convolutional network, AllCCS2 achieved exceptional prediction accuracy. AllCCS2 achieved median relative error (MedRE) values of 0.31, 0.72, and 1.64% in the training, validation, and testing sets, respectively, surpassing existing CCS prediction tools in terms of accuracy and coverage. Furthermore, AllCCS2 exhibited excellent compatibility with different instrument platforms (DTIMS, TWIMS, and TIMS). The prediction uncertainties in AllCCS2 from the training data and the prediction model were comprehensively investigated by using representative structure similarity and model prediction variation. Notably, small molecules with high structural similarities to the training set and lower model prediction variation exhibited improved accuracy and lower relative errors. In summary, AllCCS2 serves as a valuable resource to support applications of IM-MS technologies. The AllCCS2 database and tools are freely accessible at http://allccs.zhulab.cn/.

Neural-network–based algorithm for the inverse problem of measuring K-shell ionization cross-sections of Si induced by 3–25 keV electrons and 4.5–9 keV positrons using the thick-target method

In this study, a neural network method is proposed for solving the inverse problem in the measurement of inner-shell ionization cross-sections using the thick-target method. It was applied to calculate the K-shell ionization cross-section of silicon (Si) from positron impacts in the energy range from 4.5 to 9 keV, using a Monte Carlo simulation program called PENELOPE to construct a comprehensive characteristic X-ray yield and cross-section database, serving as a foundation for training the neural network. The experimental values are compared with those obtained using regularization, yield differential, and distorted-wave Born approximation (DWBA) theoretical models. Our findings reveal that the cross-section results obtained from all three algorithms are in good agreement with the theoretical DWBA values within the error range. Moreover, our study highlights the superiority of the neural network algorithm in solving ill-posed problems, compared with traditional regularization algorithms and the yield differential method. Furthermore, we re-analyse the experimental data of electron-induced ionization cross-sections on a pure thick Si target in the energy range from 3 to 25 keV, which were originally obtained by Zhu et al. who used a regularization method. The reprocessed cross-sections obtained in this study exhibit good agreement with the reported results within the error range. To the best of our knowledge, this is the first experimental report of the K-shell ionization cross-sections of Si from positron impact.

Experimental low velocity proton and 28Siq+ induced X-ray production cross sections for select elements within 24 ≤ Z ≤ 83

Particle Induced X-ray Emission (PIXE) spectroscopy is an effectively well-established analytical technique in the low projectile mass (Z < 3) regime. This is in part due to the availability of fairly accurate theoretical models of fundamental interaction parameters such as the X-ray production cross section (XPCS). Continual development of widely used theoretical models such as the ECPSSR theory with adapted corrections in the United Atom limit (UA), Electron Capture (EC) and Multiple Ionisation (MI); requires a rich database of experimental X-ray production cross sections. Beyond the scope of proton PIXE, validated reliable theoretical models may be useful for the accurate approximation of heavy ion induced X-ray production cross sections for Heavy Ion PIXE. This requires persistent efforts aimed at contributing to the currently sparse heavy ion induced X-ray production cross section database. In this work, we report on a new experimental dataset of low energy XPCS in the 0.3 MeV/u – 1.0 MeV/u ion velocity range in Cr, Ni, Ge, Mo, Sn, W, Au and Bi due to proton and 28Siq + ion impact, with an aim at enriching and updating the current database.