Elastic Scattering Cross Sections Research Articles

Elastic scattering cross sections and transport of tin ions in extreme ultraviolet lithography sources

Energetic tin ions are created by laser produced plasmas in extreme-ultraviolet lithography sources where hydrogen must be used as a buffer gas to protect critical optical components. In this study, the quantum chemistry code NWChem is used to calculate the interatomic potential between singly ionized tin and molecular hydrogen. The interatomic potential was fit by an inverse-power potential, a modified universal ZBL potential, and a two-piece-Lennard-Jones potential which were in turn used to calculate the classical distance of closest approach, scattering angle, total elastic scattering cross sections. Furthermore, the universal Ziegler-Biersack-Littmark (ZBL) potential was used in the open-source binary collision approximation codes RustBCA as well as Stopping Range in Matter and Transport of Ion in Matter (SRIM/TRIM) to calculate ion ranges, straggling, and stopping cross sections in a hydrogen gas target.

νe → νe scattering with massive Dirac or Majorana neutrinos and general interactions

We calculate the neutrino-electron elastic scattering cross section, extending the results previously obtained in ref. [1], in the presence of generic new interactions that take into account all the effects caused by finite neutrino masses. We address the potential significance of a heavy neutrino sector during precision measurements, particularly for tau neutrinos scattering with masses in the MeV range, for which the existing upper bounds on |Uτ4|2 would result in conceivably measurable contributions. Finally, we comment on the possibility to distinguish between Dirac and Majorana neutrinos, including the analysis of the new emerging parameters and its application to illustrative model-dependent scenarios.

Study of the energy calibration of the DEAP-3600 detector using Na-22 source data and simulations

DEAP-3600 is a single-phase liquid argon (LAr) direct-detection dark matter experiment, operating 2 km underground at SNOLAB (Sudbury, Canada). The detector consists of 3.3 tons of LAr contained in a spherical acrylic vessel. At WIMP mass of 100 GeV, DEAP-3600 has a projected sensitivity of 10-46 cm2 for the spin independent elastic scattering cross section of WIMPs. Radioactive sources have been used for the energy calibration and to test the detector performance. One of the most effective calibration run has been taken with a 22Na source deployed in a tube located around the DEAP-3600 steel shell. The simultaneous emission of three γs by the source provides an excellent tagging for the 22Na decay. The results concerning the energy response of the detector and the agreement between data and Monte Carlo simulations in DEAP-3600 are investigated in this study.

Secluded scalar dark matter and the muon anomalous magnetic moment

Abstract We consider a dark matter model with a singlet scalar, $\chi$, as our dark matter (DM) candidate which is secluded from the Standard Model (SM) and annihilates to the singlet scalar, $\phi$, via a contact interaction. 
The singlet scalar, $\phi$, has a leptophilic interaction with the SM leptons 
and may decay leptonically at tree level, and decays into a pair of photons at loop level. 
The focus in this work is to consider DM masses below 10 GeV. 
It is found a viable secluded region in the parameter space after imposing the observed 
relic density. There is a one-loop interaction between scalar dark matter and the atomic electron in this model. We then apply the available direct detection bounds from Xenon10, Xenon1T, and DarkSide on the DM-electron elastic scattering cross section. While the model can explain the muon anomalous magnetic moment, we put bounds from current and future lepton collider experiments.

Near-resonant light scattering by an atom in a state-dependent trap

Abstract There are an increasing number of experimental scenarios where near-resonant light is applied to atoms tightly trapped in far off-resonant optical fields, such as for quantum optics applications or for atom imaging. Oftentimes, the electronic ground and excited states involved in the optical transition experience unequal trapping potentials. Here, we systematically analyze the effects of unequal trapping on near-resonant atom–light interactions. In particular, we identify regimes where such trapping can lead to significant excess heating compared to atoms in state-independent potentials, and a reduction of total and elastic scattering cross sections associated with a decreased atom–photon interaction efficiency. Understanding these effects can be valuable for achieving maximum efficiency in quantum optics experiments or atom imaging setups, where efficient atom–light interactions on resonance are desired, but achieving equal trapping is not feasible.

Calculation And Uncertainty Analysis of Core Parameters of ALMANAR Reactor Using New Nuclear Data Libraries

Abstract A small modular lead-cooled fast spectrum core concept called ALMANAR designed to produce 45 MWth power for 22 years operating without refuelling was proposed in a previous study. The neutronics investigation showed its excellent inherent safety features. It could be considered as a candidate for future electricity source for the near future. It is noteworthy that the target accuracy for eigenvalue calculation for keff regardless of spectrum is set to 300 pcm. However, findings in this analysis revealed that the keff uncertainty was larger for the recently released nuclear data libraries (about 800 pcm), mostly from 235U capture cross section (624 pcm) in the case of ENDF/B-VIII.0 and 238U inelastic scattering cross section (437 pcm) in the case of JENDL-5. Selected kinetic parameters of the ALMANAR core and their uncertainty were also evaluated and analysed. No major impact on the total ßeff, leffeff and λeff simulation results was found. In order to improve the reliability of criticality calculations of the lead-cooled small fast reactor, the accuracy of capture and fission cross section of 235,238U, the capture cross section of 10B and the elastic scattering cross section of 208Pb at the fast energy range of ENDF/B-VIII.0 should be improved. Furthermore, the inelastic scattering and capture cross section of 238U, fission and capture cross section of 235U and the capture cross section of 10B of JENDL-5 should also be improved.

Investigation of elastic scattering cross-sections of electron with neon atoms

In the present study, Integral [QI(E)], Momentum transfer [QM(E)] and Total [QT(E)] cross-sections have been successfully determined for the elastic scattering of electrons with Neon (Ne) atoms in intermediate incident energy range (100 – 500 eV). The Partial Wave Analysis (PWA) method and modified absorption potential of Raj and Kumar, Phys. Letters A 282 (2001) 284 have been employed to investigate these cross-sections. The present results were compared with the existing experimental data and theoretical calculations for the different cross-sections. These results were in better agreement with the existing studies of cross-sections.

Series representation of differential elastic scattering cross section for electrons: Applications in theoretical models of electron transport in condensed matter

Series representation of differential elastic scattering cross section for electrons: Applications in theoretical models of electron transport in condensed matter

A multichannel algebraic scattering approach to astrophysical reactions

The investigation of many astrophysical processes is dependent upon an understanding of nuclear reaction rates. However, nuclear capture reactions of astrophysical interest occur at extremely low energies, taking place at the Gamow energy within the stellar environment. Hence, they are hard to study experimentally due to Coulomb repulsion. They may also involve compound resonances stemming from a delicate interplay of many quantum states in the colliding bodies. The multi-channel algebraic scattering (MCAS) method is one that addresses both of these challenges; it has a history of successfully modelling narrow compound resonance structures, incorporating as many channels as are important for a given problem, but is also proven in recreating the lowenergy, non-resonant elastic scattering cross sections needed for these astrophysics problems. We provide an overview of MCAS’ techniques of modelling elastic scattering reactions, how these may be extended to capture reactions, and current work in this area.

Positron and Electron Impact Elastic Scattering by Atomic Beryllium

Theoretical results for positron and electron elastic scattering from beryllium atom at incident energies ranging from the first inelastic threshold to 200 eVare presented. Elastic, total, momentum transfer, and differential cross sections are computed using both the first order distorted wave Born approximation andthe optical potential approaches utilizing a complex potential. We have shown that our data agree fairly well with the available data and provided the details of thePhysics in case of discrepancies. This study demonstrates the importance of accurate atomic elastic scattering cross sections.

Lighting up the LHC with Dark Matter

We show that simultaneously explaining dark matter and the observed value of the muon’s magnetic dipole moment may lead to yet unexplored photon signals at the LHC. We consider the Minimal Supersymmetric Standard Model with electroweakino masses in the few-to-several hundred GeV range, and opposite sign of the Bino mass parameter with respect to both the Higgsino and Wino mass parameters. In such region of parameter space, the spin-independent elastic scattering cross section of a Bino-like dark matter candidate in direct detection experiment is suppressed by cancellations between different amplitudes, and the observed dark matter relic density can be realized via Bino-Wino co-annihilation. Moreover, the observed value of the muon’s magnetic dipole moment can be explained by Bino and Wino loop contributions. Interestingly, “radiative” decays of Wino-like neutralinos into the lightest neutralino and a photon are enhanced, whereas decays into leptons are suppressed. While these decay patterns weaken the reach of multi-lepton searches at the LHC, the radiative decay opens a new window for probing dark matter at the LHC through the exploration of parameter space regions beyond those currently accessible. To complement the current electroweakino searches, we propose searching for a single (soft) photon plus missing transverse energy, accompanied by a hard initial state radiation jet.

Study of electron- and positron-induced elastic scattering cross sections of lead atoms

Study of electron- and positron-induced elastic scattering cross sections of lead atoms

Analysis of α + 16O elastic scattering in the semi-microscopical dispersive optical model

We study the elastic scattering cross sections of the α +16O system at 49.5, 69.5, and 80.7 MeV using the optical potentials calculated in the framework of the semi-microscopical dispersive optical model. In this model, the optical potential contains an energy-independent part calculated in the double folding model with a realistic effective nucleon-nucleon interaction, as well as an energy-dependent dynamic polarization potential, the parameters of which are adjusted to the data. The parameters of the real and imaginary parts of the dynamic polarization potential are connected by the dispersion relations.

Multi-method treatment of elastic scattering of alpha particles from atomic hydrogen over a wide impact energy range

Multiple theoretical methods are used to calculate the elastic scattering cross section for collisions of alpha particles with atomic hydrogen in the center-of-mass energy range of 10−4–108 eV. At the lowest energies where elastic scattering greatly dominates other reaction channels, a single-channel quasi-molecular-orbital approach is used. With the opening of inelastic channels at higher energies the multi-channel atomic-orbital, close-coupling method is applied, and at the highest energies considered perturbation theory (the Born approximation) is used. The results are compared with other data available in the literature and from preliminary multi-channel molecular-orbital, close-coupling calculations in order to assess the accuracy of the results and to create a recommended set of data spanning the entire energy range. The data is made available for use in astrophysical modeling and other plasma science applications online.

Cored dark matter halos in the cosmic neutrino background

We study the impact of the interaction between DM and the cosmic neutrino background on the evolution of galactic dark matter halos. The energy transfer from the cosmic background neutrinos to galactic dark matter can heat the center of the galaxy and make it cored. The core formation is efficient for the small galaxies such as the satellite galaxies of the Milky Way and we can put a conservative constraint on the non-relativistic elastic scattering cross section as σχν ≲ 10-31 cm2 for 0.1 keV dark matter.

а- бөлшектердің 9Be ядросымен соқтығысу кезіндегі серпімді шашырауының жаһандық заңдылықтары

The article investigates the characteristics of the experimental data of the elastic scattering cross section in the low-energy range of the a+9Be nuclear system. General regularities depending on the change in the energy of accelerated ions of the parameters of the obtained cross sections are established. Based on the analysis in the framework of the optical model (OM), energy-dependent optical interaction potentials in a wide range of energies were found.The energy regularity of potentials, revealed as a result of systematic analysis, makes it possible to predict with sufficient accuracy the cross-section of processes at energies at which experimental measurements were not carried out.The potential, which is a complex function of the interaction between nuclei, is an empirical measurement that describes the interaction in the scattering process.Studies of the dependence of the potential on external factors should be carried out individually for each nuclear system. Such analyses carried out in order to improve the accuracy of phenomenological theories should be based on a large array of experimental data. To clarify the truthfulness of the results of phenomenological approaches, it would be theoretically more correct to determine the global patterns of potentials and energy dependences of the full reaction cross-section.The article defines the energy dependence of the potentials and the total cross-section of the reaction based on a systematic analysis of the experimental data set in the energy range of laboratory Elab=30 - 60 MeV for the α+9Be process.Optimal values of the cross-section parameters satisfying global laws depending on the energy of the accelerating beam are found.

An extensive theoretical quantification of secondary electron emission from silicon

Though intensive experimental studies have been carried out on electron emission properties in past decades, the reliable data from accurate experimental measurements for clean and smooth surfaces are still quite limited. In this work, we have performed a comprehensive Monte Carlo simulation of electron emission yields, the secondary electron yield (SEY, δ), backscattered electron coefficient (BSC, η) and total electron yield (TEY, σ=δ+η), from silicon and the uncertainty quantification of the theoretical calculation results for the first time. The simulations were made on total 17280 scattering models. The considered uncertainty factors in the physical modelling that can influence the calculated yields include work function data, optical energy loss function data, dielectric function models for electron inelastic scattering and the scattering potentials for electron elastic scattering. The calculation results show that δ is significantly influenced by the work function while the dielectric function model has a slight effect. Elastic scattering potential (or elastic scattering cross section) and energy loss function affects to a certain extent both δ and η. Our simulated η data agree with most of the experimental measurements while the simulated mean δ data are well below most of the experimental data. At a 75% level of confidence, the experimental σ data measured by Goto et al. lie within the uncertainty range of our simulation results. This work has provided sufficient ground for the necessity of building a theoretical database of electron emission yield considering the fact that most of the previous experimental data are not reliable due to the presence of surface contamination during the measurements.

On particle scattering in Gross-Pitaevskii theory and implications for dark matter halos

Bose-Einstein-condensed dark matter (BEC-DM), also called scalar field dark matter (SFDM), has become a popular alternative to the standard, collisionless cold dark matter (CDM) model, due to its long-held potential to resolve the small-scale crisis of CDM. Halos made of BEC-DM have been modelled using the Gross-Pitaevskii (GP) equation coupled to the Poisson equation; the so-called GPP equations of motion. These equations are based on fundamental microphysical conditions that need to be fulfilled in order for the equations to be valid in the first place, related to the diluteness of the DM gas and the nature of the particle scattering model. We use these conditions in order to derive the implications for the BEC-DM parameters, the 2-particle self-interaction coupling strength g and the particle mass m. We compare the derived bounds with the constraint that results from the assumption of virial equilibrium of the central cores of halos, deriving a relationship that connects g and m. We find that the GPP conditions are greatly fulfilled, for BEC-DM particle masses of interest, if such models also obey the virial condition that turns out to be the strongest constraint. We also derive the implications for the elastic scattering cross section (per particle mass) in BEC-DM halos, based on the scattering model of GPP, and find a huge range of possible values, depending on the self-interaction regime. We put our results into context to recent literature which predicts sub-kpc core size in BEC-DM halos.

Theoretical Study on 10C Elastic Scattering Cross Sections Using Different Cluster Density Distributions and Different Potentials

Elastic scattering cross sections are a fundamental aspect of nuclear physics research, and studying the cross sections of various nuclei can provide important insights into the behavior of nuclei. In this study, the elastic scattering cross sections of 10C projectile by 27Al, 58Ni, and 208Pb target nuclei are analyzed. The aim of this study is to investigate the cluster structure of 10C and the sensitivity of the elastic scattering cross sections to different potentials. To achieve this objective, the double folding optical model and a simple cluster approach are used to analyze the cross sections. The real part of the optical potential is obtained by folding two different effective interactions, Michigan-3-Yukawa (M3Y) and JeukenneLejeune-Mahaux (JLM), with four different cluster density distributions of the 10C nucleus: 6Be + \alpha, 9B + p, 8Be + p + p, and \alpha + \alpha + p + p. The imaginary part is taken to be a Woods-Saxon phenomenological form. The sensitivity of the elastic scattering cross sections to different potentials is assessed by comparing the results obtained using different potentials. The cluster structure of 10C is validated by comparing the theoretical results with experimental data. The results show that the cross sections are sensitive to the choice of potential used and that the cluster structure of 10C is validated. The theoretical results show reasonable agreement with the experimental data.

Cross Sections for Coherent Elastic and Inelastic Neutrino-Nucleus Scattering

The prospects of extracting new physics signals in coherent elastic neutrino–nucleus scattering (CEνNS) processes are limited by the precision with which the underlying nuclear structure physics, embedded in the weak nuclear form factor, is known. We present calculations of charge and weak nuclear form factors and CEνNS cross sections on 12C, 16O, 40Ar, 56Fe and 208Pb nuclei. We obtain the proton and neutron densities, and charge and weak form factors by solving Hartree–Fock (HF) equations with a Skyrme (SkE2) nuclear potential. We validate our approach by comparing 208Pb and 40Ar charge form factor predictions with available elastic electron scattering data. Since CEνNS experiments at stopped-pion sources are also well suited to measure inelastic charged–current and neutral–current neutrino–nucleus cross sections, we also present calculations for these processes, incorporating a continuum Random Phase Approximation (CRPA) description on top of the HF–SkE2 picture of the nucleus. Providing both coherent as well as inelastic cross sections in a consistent framework, we aim at obtaining a reliable and detailed comparison of the strength of these processes in the energy region below 100 MeV. Furthermore, we attempt to gauge the level of theoretical uncertainty pertaining to the description of the 40Ar form factor and CEνNS cross sections by comparing relative differences between recent microscopic nuclear theory and widely-used phenomenological form factor predictions. Future precision measurements of CEνNS will potentially help in constraining these nuclear structure details that will in turn improve prospects of extracting new physics.