Elastic scattering reaction of on partial wave scattering matrix, differentia...Alexander Decker
This document analyzes the elastic scattering reaction of helium-4 and boron-10 at laboratory energies of 5-15 MeV using an optical model. The optical model approximates the interaction between projectile and target nuclei as a complex optical potential. Six optical parameters describe this potential, including the depth, Coulomb radius, and diffuseness of the real and imaginary parts. Five of the parameters were varied to calculate the partial wave scattering matrix, differential cross section, and reaction cross section ratio to the Rutherford cross section. The results provide angular distributions of the reaction cross sections and differential cross sections from center-of-mass angles of 0-180 degrees for energies of 5, 7, 12, and 15 MeV.
Laser Pulsing in Linear Compton ScatteringTodd Hodges
This document summarizes a method for calculating the energy spectrum of radiation produced in linear Compton scattering, accounting for the pulsed structure of the incident laser beam. The method involves performing a Lorentz transformation of the Klein-Nishina scattering cross section to calculate the emission from individual electrons in an electron beam, and then summing over all electrons to obtain the total energy spectrum. This approach allows for accurate modeling of effects of electron beam energy spread and emittance. The method is then applied to predict the photon spectrum from a proposed compact inverse Compton scattering x-ray source at Old Dominion University.
Apartes de la Conferencia de la SJG del 14 y 21 de Enero de 2012Nonlinear ele...SOCIEDAD JULIO GARAVITO
This document summarizes a research article about nonlinear electrodynamics and its effects on the polarization of the cosmic microwave background radiation. It introduces nonlinear electrodynamics models as alternatives to Maxwell's electrodynamics. The document then discusses how nonlinear electrodynamics is minimally coupled to gravity and derives the relevant equations of motion. It focuses on analyzing the Pagels-Tomboulis nonlinear electrodynamics Lagrangian and computing the polarization angle of photons propagating in an expanding universe with planar symmetry. Constraints on the nonlinear electrodynamics parameter are obtained using data on cosmic magnetic field strengths and the rotation of CMB polarization spectra measured by experiments.
The document discusses properties of the nucleus, including:
- The nucleus contains positively charged protons and uncharged neutrons.
- Isotopes of an element have the same number of protons but different numbers of neutrons.
- A mass spectrometer can be used to separate isotopes based on their different masses, producing a characteristic pattern on a photographic plate.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Ultracold atoms in superlattices as quantum simulators for a spin ordering mo...Alexander Decker
This document discusses using ultracold fermionic atoms in optical lattices to simulate spin ordering models. It begins by describing how atoms can be trapped in optical lattices using laser light. It then proposes how a spin ordering Hamiltonian could be used to achieve superexchange interaction in a double well system. Finally, it suggests going beyond double wells to study resonating valence bond states in a kagome lattice, which could provide insights into phenomena like high-temperature superconductivity.
NANO281 is the University of California San Diego NanoEngineering Department's first course on the application of data science in materials science. It is taught by Professor Shyue Ping Ong of the Materials Virtual Lab (http://www.materialsvirtuallab.org).
Modern electronic structure codes give relatively consistent equations of state. There remain challenges to fully automating electronic structure calculations, such as developing robust materials analysis software to integrate calculations, detecting and correcting errors, and managing scientific workflows. Frameworks like pymatgen, ASE, the Materials Project, AiiDA and Custodian provide modular, reusable tools for high-throughput electronic structure computations and extensive materials analysis capabilities. FireWorks serves as a workflow manager to automate calculations over diverse supercomputing resources. With automation comes large quantities of materials data that can be leveraged for materials design and discovery.
Elastic scattering reaction of on partial wave scattering matrix, differentia...Alexander Decker
This document analyzes the elastic scattering reaction of helium-4 and boron-10 at laboratory energies of 5-15 MeV using an optical model. The optical model approximates the interaction between projectile and target nuclei as a complex optical potential. Six optical parameters describe this potential, including the depth, Coulomb radius, and diffuseness of the real and imaginary parts. Five of the parameters were varied to calculate the partial wave scattering matrix, differential cross section, and reaction cross section ratio to the Rutherford cross section. The results provide angular distributions of the reaction cross sections and differential cross sections from center-of-mass angles of 0-180 degrees for energies of 5, 7, 12, and 15 MeV.
Laser Pulsing in Linear Compton ScatteringTodd Hodges
This document summarizes a method for calculating the energy spectrum of radiation produced in linear Compton scattering, accounting for the pulsed structure of the incident laser beam. The method involves performing a Lorentz transformation of the Klein-Nishina scattering cross section to calculate the emission from individual electrons in an electron beam, and then summing over all electrons to obtain the total energy spectrum. This approach allows for accurate modeling of effects of electron beam energy spread and emittance. The method is then applied to predict the photon spectrum from a proposed compact inverse Compton scattering x-ray source at Old Dominion University.
Apartes de la Conferencia de la SJG del 14 y 21 de Enero de 2012Nonlinear ele...SOCIEDAD JULIO GARAVITO
This document summarizes a research article about nonlinear electrodynamics and its effects on the polarization of the cosmic microwave background radiation. It introduces nonlinear electrodynamics models as alternatives to Maxwell's electrodynamics. The document then discusses how nonlinear electrodynamics is minimally coupled to gravity and derives the relevant equations of motion. It focuses on analyzing the Pagels-Tomboulis nonlinear electrodynamics Lagrangian and computing the polarization angle of photons propagating in an expanding universe with planar symmetry. Constraints on the nonlinear electrodynamics parameter are obtained using data on cosmic magnetic field strengths and the rotation of CMB polarization spectra measured by experiments.
The document discusses properties of the nucleus, including:
- The nucleus contains positively charged protons and uncharged neutrons.
- Isotopes of an element have the same number of protons but different numbers of neutrons.
- A mass spectrometer can be used to separate isotopes based on their different masses, producing a characteristic pattern on a photographic plate.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Ultracold atoms in superlattices as quantum simulators for a spin ordering mo...Alexander Decker
This document discusses using ultracold fermionic atoms in optical lattices to simulate spin ordering models. It begins by describing how atoms can be trapped in optical lattices using laser light. It then proposes how a spin ordering Hamiltonian could be used to achieve superexchange interaction in a double well system. Finally, it suggests going beyond double wells to study resonating valence bond states in a kagome lattice, which could provide insights into phenomena like high-temperature superconductivity.
NANO281 is the University of California San Diego NanoEngineering Department's first course on the application of data science in materials science. It is taught by Professor Shyue Ping Ong of the Materials Virtual Lab (http://www.materialsvirtuallab.org).
Modern electronic structure codes give relatively consistent equations of state. There remain challenges to fully automating electronic structure calculations, such as developing robust materials analysis software to integrate calculations, detecting and correcting errors, and managing scientific workflows. Frameworks like pymatgen, ASE, the Materials Project, AiiDA and Custodian provide modular, reusable tools for high-throughput electronic structure computations and extensive materials analysis capabilities. FireWorks serves as a workflow manager to automate calculations over diverse supercomputing resources. With automation comes large quantities of materials data that can be leveraged for materials design and discovery.
This document discusses voltammetry, an electroanalytical technique used in qualitative and quantitative analytical chemistry. It introduces the basic concepts and principles of voltammetry, including instrumentation, excitation signals, types of voltammetry, and features of voltammograms. Specifically, it discusses the fundamentals of voltammetric cells, electrodes, hydrodynamic voltammetry, and common shapes of voltammograms including linear scan and peak voltammograms. The overall purpose is to explain the fundamental concepts and applications of voltammetry as an analytical technique.
The document presents an analytical approach to estimate the range of alpha particles emitted from radon gas. It discusses the stopping power and range of charged particles as they pass through matter. Equations from Bohr and Bethe are provided to calculate stopping power. The results of simulations using SRIM2013 software to calculate alpha particle range and detection probabilities in air are presented and compared to previous SRIM versions. Tables and figures show trends in stopping power and range as alpha energy increases.
Materials Modelling: From theory to solar cells (Lecture 1)cdtpv
This document provides an overview of a mini-module on materials modelling for solar energy applications. It introduces the lecturers and outlines the course structure, which includes lectures on modelling, interfaces, and multi-scale approaches. It also describes a literature review activity where students will present a research paper using materials modelling in photovoltaics. Recommended textbooks are provided on topics like bonding in solids, computational chemistry, and density functional theory for solids.
This document provides an overview of density functional theory and methods for modeling strongly correlated materials. It discusses the limitations of standard DFT approaches like LDA for strongly correlated systems and introduces model Hamiltonians and correction methods like LDA+U, LDA+DMFT, self-interaction correction, and generalized transition state to better account for electron correlation effects. The document outlines the basic theory and approximations of DFT, including Kohn-Sham equations and the local density approximation, and discusses basis set approaches like plane waves, augmented plane waves, and pseudopotentials.
Electron Diffusion and Phonon Drag Thermopower in Silicon NanowiresAI Publications
The field of thermoelectric research has undergone a renaissance and boom in the fast two decades, largely fueled by the prospect of engineering electronic and phononic properties in nanostructures, among which semiconductor nanowires (NWs) have served both as an important platform to investigate fundamental thermoelectric transport phenomena and as a promising route for high thermoelectric performance for device applications. In this report we theoretical studied the carrier diffusion and phonon-drag contribution to thermoelectric performance of silicon nanowires and compared with the existing experimental data. We observed a good agreement between theoretical data and experimental observations in the overall temperature range from 50 – 350 K. Electron diffusion thermopower is found to be dominant mechanism in the low temperature range and shows linear dependence with temperature.
Prediction of electronic and magnetic properties of Full Heusler Alloy – Ir2CrAlIOSR Journals
This document summarizes a study that used density functional theory calculations to predict the structural, electronic, and magnetic properties of the full Heusler alloy Ir2CrAl. The calculations found that Ir2CrAl has:
1) A lattice constant of 5.9648 Å after structural optimization, with a bulk modulus of 270.9 GPa.
2) Half-metallic behavior with 100% spin polarization at the Fermi level, due to an indirect band gap of 0.3 eV in the minority spin channel.
3) Ferromagnetic ordering with a total magnetic moment of 3 μB per formula unit, in agreement with Slater-Pauling rules for Heusler alloys.
This document provides an overview of nuclear reactions including:
- Four main types of nuclear reactions: radioactive decay, bombardment with energetic particles, fusion, and fission.
- Key principles of nuclear reactions such as conservation of charge and nucleon number.
- Calculation of the energy (Q) released in nuclear reactions from the mass defect.
- Examples of calculating energy and writing equations for various nuclear reactions including alpha decay, beta decay, and bombardment reactions.
The document provides an introduction to basic nuclear physics concepts over 5 phases: 1) atomic structure, 2) binding energy and mass defect, 3) natural and artificial radioactivity, 4) fission and fusion, and 5) chain reaction, critical mass, and reflectors. It defines key terms like atom, isotope, ionization, and units of energy. It describes the structure of atoms including protons, neutrons, and electrons. It also covers natural radioactivity, types of radiation, and interactions between radiation and matter like photoelectric effect, Compton effect, and pair production.
Deep Inelastic Scattering at HERA (Hadron-Electron Ring Acceleartor)SubhamChakraborty28
A review presentation about the research and experiments done at HERA related to Deep Inelastic Scattering, High Energy Physics and Quantum Chromodynamics
Radioactive decay involves the spontaneous disintegration of atomic nuclei accompanied by emission of particles or radiation. The document discusses the properties and types of radioactive decay, including alpha, beta, and gamma decay. It defines key terms like activity, decay constant, half-life, and covers the exponential decay law. Examples are provided to illustrate concepts like calculating the number of daughter nuclei produced after a given period of time.
This document describes the tight-binding method for calculating the energy diagram of nanoelectronic systems. It introduces the tight-binding method and its application to calculating the energy diagrams of polyacetylene, single-layer graphene, bilayer graphene, and multi-layer graphene. It also discusses using the tight-binding method to calculate the energy diagrams of two and four layer graphene in a constant electric field and single-layer graphene in a modulated electric field. The document provides the theoretical framework and mathematical equations for applying the tight-binding method to these different nanoscale systems.
The document discusses density functional theory (DFT) and its implementation in the VASP software. It explains key concepts like the Kohn-Sham approach for approximating the many-body Schrodinger equation and the use of pseudopotentials and plane wave basis sets. It also summarizes some example calculations done in VASP like determining the binding energy of O2, equilibrium lattice constant of Cu, and band structures of Si and graphene. Key input and output files of VASP are also outlined.
The document provides an introduction to basic concepts in nuclear physics, including:
- Binding energy and the liquid drop model, which describes the saturation of nuclear forces.
- Nuclear dimensions and the different energy scales involved.
- The Fermi gas model, which treats nuclei as two fermion gases and can provide constants for binding energy formulas.
- The shell model, which incorporates a mean field potential and spin-orbit potential to reproduce shell structure in nuclei.
- Isospin, which treats protons and neutrons as states of a single particle to explain similarities in their behavior.
This document summarizes an experiment to verify the wave-particle duality of electrons using electron diffraction. Electrons are accelerated towards a graphite target, causing a diffraction pattern of concentric rings to appear on a fluorescent screen based on the De Broglie wavelength. The diameters of the rings were measured at different voltages and found to match closely with theoretical wavelengths calculated using De Broglie's equation, providing evidence that electrons exhibit both wave and particle properties.
This study measured the X-ray fluorescence spectra of chromium compounds with different oxidation states (Cr0, Cr3+, Cr6+) using a high-resolution crystal spectrometer. Second-order contributions like plasmon satellites were resolved below the main Kβ1,3 emission line. The intensities and energies of these satellites varied between the compounds. Specifically, the Kβ' satellite had higher intensity and was at a lower energy for Cr3+ compared to Cr6+ or Cr0. Similar trends were observed for other satellites like Kβ5. The results provide information about how chemical bonding affects X-ray emission spectra.
The document summarizes key topics in the chapter on nuclear physics, including:
1) The structure and properties of the nucleus, including its composition of protons and neutrons.
2) The discovery of the neutron by James Chadwick in 1932, which helped explain nuclear structure.
3) The strong and weak nuclear forces that bind nucleons together in the nucleus.
This document describes a new tissue-equivalent plastic called A-181 that accurately simulates the photon and neutron absorption properties of brain tissue. A-181 was formulated to match the recommended hydrogen and nitrogen content of brain tissue for applications using low-energy neutrons like boron neutron capture therapy (BNCT). Measurements using A-181 and the standard muscle tissue equivalent plastic A-150 in a BNCT beam show good agreement with Monte Carlo calculations and demonstrate A-181's suitability for neutron dosimetry in brain tissue.
Younes Sina's presentation on Nuclear reaction analysisYounes Sina
This document discusses nuclear reaction analysis (NRA), a technique used for light element depth profiling. NRA works by detecting reaction products from nuclear reactions between an ion beam and sample nuclei. The document covers the basic principles of NRA, including electronic and nuclear stopping, elastic and inelastic collisions. It also discusses various nuclear reactions used in NRA, experimental setup, data analysis methods, applications including depth profiling and limitations.
Comparative Study of Evolutionary Algorithms for the Optimum Design Of Thin B...jmicro
With the increasing levels of Electromagnetic pollution almost exponentially in this modern age of
Electronics reported and highlighted by numerous studies carried out by scientists from all over the world,
inspire engineers to concentrate their research for the optimum design of multilayer microwave absorber
considering various parameters which are inherently conflicting in nature. In this paper we mainly focus
on the comparative study of different Evolutionary algorithms for the optimum design of thin broadband (2-
20GHz) multilayer microwave absorber for oblique incidence (300
) considering arbitrary polarization of
the electromagnetic waves. Different models are presented and synthesized using various Evolutionary
algorithm namely Firefly algorithm (FA), Particle swarm optimization (PSO), Artificial bee colony
optimization (ABC) and the best simulated results are tabulated and compared with each others.
This document discusses voltammetry, an electroanalytical technique used in qualitative and quantitative analytical chemistry. It introduces the basic concepts and principles of voltammetry, including instrumentation, excitation signals, types of voltammetry, and features of voltammograms. Specifically, it discusses the fundamentals of voltammetric cells, electrodes, hydrodynamic voltammetry, and common shapes of voltammograms including linear scan and peak voltammograms. The overall purpose is to explain the fundamental concepts and applications of voltammetry as an analytical technique.
The document presents an analytical approach to estimate the range of alpha particles emitted from radon gas. It discusses the stopping power and range of charged particles as they pass through matter. Equations from Bohr and Bethe are provided to calculate stopping power. The results of simulations using SRIM2013 software to calculate alpha particle range and detection probabilities in air are presented and compared to previous SRIM versions. Tables and figures show trends in stopping power and range as alpha energy increases.
Materials Modelling: From theory to solar cells (Lecture 1)cdtpv
This document provides an overview of a mini-module on materials modelling for solar energy applications. It introduces the lecturers and outlines the course structure, which includes lectures on modelling, interfaces, and multi-scale approaches. It also describes a literature review activity where students will present a research paper using materials modelling in photovoltaics. Recommended textbooks are provided on topics like bonding in solids, computational chemistry, and density functional theory for solids.
This document provides an overview of density functional theory and methods for modeling strongly correlated materials. It discusses the limitations of standard DFT approaches like LDA for strongly correlated systems and introduces model Hamiltonians and correction methods like LDA+U, LDA+DMFT, self-interaction correction, and generalized transition state to better account for electron correlation effects. The document outlines the basic theory and approximations of DFT, including Kohn-Sham equations and the local density approximation, and discusses basis set approaches like plane waves, augmented plane waves, and pseudopotentials.
Electron Diffusion and Phonon Drag Thermopower in Silicon NanowiresAI Publications
The field of thermoelectric research has undergone a renaissance and boom in the fast two decades, largely fueled by the prospect of engineering electronic and phononic properties in nanostructures, among which semiconductor nanowires (NWs) have served both as an important platform to investigate fundamental thermoelectric transport phenomena and as a promising route for high thermoelectric performance for device applications. In this report we theoretical studied the carrier diffusion and phonon-drag contribution to thermoelectric performance of silicon nanowires and compared with the existing experimental data. We observed a good agreement between theoretical data and experimental observations in the overall temperature range from 50 – 350 K. Electron diffusion thermopower is found to be dominant mechanism in the low temperature range and shows linear dependence with temperature.
Prediction of electronic and magnetic properties of Full Heusler Alloy – Ir2CrAlIOSR Journals
This document summarizes a study that used density functional theory calculations to predict the structural, electronic, and magnetic properties of the full Heusler alloy Ir2CrAl. The calculations found that Ir2CrAl has:
1) A lattice constant of 5.9648 Å after structural optimization, with a bulk modulus of 270.9 GPa.
2) Half-metallic behavior with 100% spin polarization at the Fermi level, due to an indirect band gap of 0.3 eV in the minority spin channel.
3) Ferromagnetic ordering with a total magnetic moment of 3 μB per formula unit, in agreement with Slater-Pauling rules for Heusler alloys.
This document provides an overview of nuclear reactions including:
- Four main types of nuclear reactions: radioactive decay, bombardment with energetic particles, fusion, and fission.
- Key principles of nuclear reactions such as conservation of charge and nucleon number.
- Calculation of the energy (Q) released in nuclear reactions from the mass defect.
- Examples of calculating energy and writing equations for various nuclear reactions including alpha decay, beta decay, and bombardment reactions.
The document provides an introduction to basic nuclear physics concepts over 5 phases: 1) atomic structure, 2) binding energy and mass defect, 3) natural and artificial radioactivity, 4) fission and fusion, and 5) chain reaction, critical mass, and reflectors. It defines key terms like atom, isotope, ionization, and units of energy. It describes the structure of atoms including protons, neutrons, and electrons. It also covers natural radioactivity, types of radiation, and interactions between radiation and matter like photoelectric effect, Compton effect, and pair production.
Deep Inelastic Scattering at HERA (Hadron-Electron Ring Acceleartor)SubhamChakraborty28
A review presentation about the research and experiments done at HERA related to Deep Inelastic Scattering, High Energy Physics and Quantum Chromodynamics
Radioactive decay involves the spontaneous disintegration of atomic nuclei accompanied by emission of particles or radiation. The document discusses the properties and types of radioactive decay, including alpha, beta, and gamma decay. It defines key terms like activity, decay constant, half-life, and covers the exponential decay law. Examples are provided to illustrate concepts like calculating the number of daughter nuclei produced after a given period of time.
This document describes the tight-binding method for calculating the energy diagram of nanoelectronic systems. It introduces the tight-binding method and its application to calculating the energy diagrams of polyacetylene, single-layer graphene, bilayer graphene, and multi-layer graphene. It also discusses using the tight-binding method to calculate the energy diagrams of two and four layer graphene in a constant electric field and single-layer graphene in a modulated electric field. The document provides the theoretical framework and mathematical equations for applying the tight-binding method to these different nanoscale systems.
The document discusses density functional theory (DFT) and its implementation in the VASP software. It explains key concepts like the Kohn-Sham approach for approximating the many-body Schrodinger equation and the use of pseudopotentials and plane wave basis sets. It also summarizes some example calculations done in VASP like determining the binding energy of O2, equilibrium lattice constant of Cu, and band structures of Si and graphene. Key input and output files of VASP are also outlined.
The document provides an introduction to basic concepts in nuclear physics, including:
- Binding energy and the liquid drop model, which describes the saturation of nuclear forces.
- Nuclear dimensions and the different energy scales involved.
- The Fermi gas model, which treats nuclei as two fermion gases and can provide constants for binding energy formulas.
- The shell model, which incorporates a mean field potential and spin-orbit potential to reproduce shell structure in nuclei.
- Isospin, which treats protons and neutrons as states of a single particle to explain similarities in their behavior.
This document summarizes an experiment to verify the wave-particle duality of electrons using electron diffraction. Electrons are accelerated towards a graphite target, causing a diffraction pattern of concentric rings to appear on a fluorescent screen based on the De Broglie wavelength. The diameters of the rings were measured at different voltages and found to match closely with theoretical wavelengths calculated using De Broglie's equation, providing evidence that electrons exhibit both wave and particle properties.
This study measured the X-ray fluorescence spectra of chromium compounds with different oxidation states (Cr0, Cr3+, Cr6+) using a high-resolution crystal spectrometer. Second-order contributions like plasmon satellites were resolved below the main Kβ1,3 emission line. The intensities and energies of these satellites varied between the compounds. Specifically, the Kβ' satellite had higher intensity and was at a lower energy for Cr3+ compared to Cr6+ or Cr0. Similar trends were observed for other satellites like Kβ5. The results provide information about how chemical bonding affects X-ray emission spectra.
The document summarizes key topics in the chapter on nuclear physics, including:
1) The structure and properties of the nucleus, including its composition of protons and neutrons.
2) The discovery of the neutron by James Chadwick in 1932, which helped explain nuclear structure.
3) The strong and weak nuclear forces that bind nucleons together in the nucleus.
This document describes a new tissue-equivalent plastic called A-181 that accurately simulates the photon and neutron absorption properties of brain tissue. A-181 was formulated to match the recommended hydrogen and nitrogen content of brain tissue for applications using low-energy neutrons like boron neutron capture therapy (BNCT). Measurements using A-181 and the standard muscle tissue equivalent plastic A-150 in a BNCT beam show good agreement with Monte Carlo calculations and demonstrate A-181's suitability for neutron dosimetry in brain tissue.
Younes Sina's presentation on Nuclear reaction analysisYounes Sina
This document discusses nuclear reaction analysis (NRA), a technique used for light element depth profiling. NRA works by detecting reaction products from nuclear reactions between an ion beam and sample nuclei. The document covers the basic principles of NRA, including electronic and nuclear stopping, elastic and inelastic collisions. It also discusses various nuclear reactions used in NRA, experimental setup, data analysis methods, applications including depth profiling and limitations.
Comparative Study of Evolutionary Algorithms for the Optimum Design Of Thin B...jmicro
With the increasing levels of Electromagnetic pollution almost exponentially in this modern age of
Electronics reported and highlighted by numerous studies carried out by scientists from all over the world,
inspire engineers to concentrate their research for the optimum design of multilayer microwave absorber
considering various parameters which are inherently conflicting in nature. In this paper we mainly focus
on the comparative study of different Evolutionary algorithms for the optimum design of thin broadband (2-
20GHz) multilayer microwave absorber for oblique incidence (300
) considering arbitrary polarization of
the electromagnetic waves. Different models are presented and synthesized using various Evolutionary
algorithm namely Firefly algorithm (FA), Particle swarm optimization (PSO), Artificial bee colony
optimization (ABC) and the best simulated results are tabulated and compared with each others.
Nuclear physics describes the structure and interactions of atomic nuclei. Rutherford discovered the nucleus through alpha scattering experiments. Protons and neutrons were later identified. Isotopes have the same number of protons but different numbers of neutrons. Mass defect and binding energy explain why atomic nuclei are more stable than separated nucleons. Radioactive decay occurs spontaneously at a rate proportional to the number of unstable nuclei. Exponential decay and half-life are described by the decay constant. Nuclear reactions conserve nucleon number and charge. Energy is released or absorbed through mass-energy equivalence. Fission and fusion occur under different conditions according to binding energy. Controlled fission in reactors uses moderation and feedback to sustain a chain reaction. Fusion
L8 Introduction to Reactor Physics Part 1.pdfRHOWELLETIBAY1
- The document provides an introduction to reactor physics concepts including neutron interactions, nuclear cross sections, reaction rates, neutron moderation, and neutron attenuation.
- It describes various neutron interactions such as elastic scattering, inelastic scattering, radiative capture, charge production, neutron production, and fission. Microscopic and macroscopic cross sections, and their relationship to reaction rates are also covered.
- The concepts of neutron moderation, thermalization, and the role of moderators are summarized. An ideal moderator is described as having a large scattering cross section, small absorption cross section, and large energy loss per collision.
The document provides an overview of the structure of matter from elementary particles to atoms and molecules. It discusses leptons, quarks, hadrons, photons and their properties. Quantum mechanics principles including the Schrodinger equation, Heisenberg uncertainty principle, and quantum numbers are covered. Atomic structure of hydrogen including energy levels, emission spectra and ionization is summarized. Mass defect and nuclear binding energy are also addressed.
This document provides an overview of basic chemistry concepts including:
- The law of multiple proportions and how it is illustrated by nitrogen and hydrogen oxides.
- Definitions of a mole and how it is used to calculate the number of hydrogen atoms in 1 mole of methane.
- How stoichiometry is used to calculate the amount of water formed from the combustion of a given amount of methane.
- The concept of a limiting reagent and how to calculate the mass of a product given specific amounts of reactants.
- A summary of the key observations and conclusions from Rutherford's gold foil experiment that led to the nuclear model of the atom.
Steady state mathematical modeling of solid oxide fuel cell for hybrid system...IAEME Publication
This document discusses the theoretical calculation of ionization cross sections for the K-shell, L-shell, and M-shell of bismuth atoms due to electron impacts. The Khare model was modified to calculate these cross sections from the ionization threshold to 1 GeV. The calculated cross sections show good agreement with available experimental data for K-shell and L-shell ionization but overestimate experimental data for M-shell ionization. The modifications improve agreement between theory and experiment over a wide energy range.
K-SHELL L-SHELL AND M-SHELL IONIZATION CROSS SECTIONS OF BISMUTH ATOM BY ELEC...IAEME Publication
The theoretical model, developed by Khare model, ha s been modified to calculate the total cross sections for K-shell L-shell and M-shell ionization of Bismuth (Z=83) atom due to electron impact at incident electron energy from ionization threshold to 1 GeV. The various calculated cross sections are in remarkable agreement with available experimental data and other theoretical cross sections.
Norman John Brodeur worked at MIT’s instrumentation lab which later became Draper Labs. My responsibility was instrumentation and guidance systems for the Apollo command module and the lunar module. Previous to that I worked for Avco-Everett Research Lab in Everett. There we focused on testing materials for the vehicle’s heat shield. I was doing heat studies of various materials and what we eventually developed would just burn off and the heat with it.
Optical and Impedance Spectroscopy Study of ZnS NanoparticlesIJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Performance analysis of a monopole antenna with fluorescent tubes at 4.9 g hz...Alexander Decker
This document describes the analysis of a monopole antenna design with fluorescent tubes at an operating frequency of 4.9 GHz. The antenna structure consists of 12 commercial fluorescent tubes surrounding a monopole antenna located in the center of a circular ground plane. The performance of the antenna design is analyzed using CST Microwave Studio software. Parameters like return loss, radiation pattern, and gain are evaluated to analyze the antenna's performance. The fluorescent tubes act as plasma reflectors when electrified, trapping radiation inside and improving the antenna's performance for potential military applications.
The document investigates the mechanical properties of carbon nanotubes (CNTs) and buckysheets using molecular dynamics (MD) simulations.
MD simulations determine the Young's modulus of single-walled CNTs is between 0.75-0.9 TPa. Simulations of single layer buckysheets yield a Young's modulus of around 0.3 TPa. As the separation distance between CNTs in buckysheet models increases, the Young's modulus decreases. Comparisons with experimental data on buckysheets show discrepancies in Young's modulus values due to impurities and structural imperfections not captured in the MD simulations. The study implies buckysheet strengths will approach that of CNTs as
Theoretical study of electronic properties of some aromatic ringsAlexander Decker
The document summarizes a theoretical study on the electronic properties of aromatic rings containing nitrogen atoms. Density functional theory was used to calculate properties of pyridine, pyrimidine, pyrazine and pyridazine, with nitrogen in different positions on a benzene ring. Key results showed adding nitrogen decreased energy gaps and improved electronic properties compared to benzene. Calculated properties included optimized structures, total energies, electronic states, energy gaps, ionization potentials, electron affinities, and vibration frequencies, with B3LYP/DFT showing good agreement with available experimental data.
This document discusses small angle neutron scattering (SANS) and its application to studying nanoparticles. It provides background on neutron sources, neutron scattering techniques including SANS, SANS instrumentation, and examples of SANS applications. SANS is used to determine the structure, size, shape, size distribution, and interactions of nanoparticles on length scales of 10-1000 Angstroms. The document then describes experiments conducted using the SANS instrument at DHRUVA reactor to analyze various nanoparticle samples.
Phonon frequency spectrum through lattice dynamics and normal coordinate anal...Alexander Decker
The document discusses the lattice dynamics and normal coordinate analysis of the high-temperature superconductor Tl2Ca3Ba2Cu4O12. It presents the following key points:
1. Lattice dynamics calculations using the three-body force shell model reproduce observed Raman and infrared phonon frequencies reasonably well.
2. Normal coordinate analysis using Wilson's F-G matrix method yields vibrational frequencies in good agreement with experimental values and lattice dynamics calculations.
3. Potential energy distribution calculations confirm that the chosen vibrational frequencies make the maximum contribution to the potential energy of the material's normal coordinate frequencies.
8m_ATOMS__NUCLEI.pdf chapter best notes preparation30jayporwal
Rutherford's alpha scattering experiment showed that the atom consists of a small, dense nucleus surrounded by empty space. Most alpha particles passed through the gold foil, but a small percentage were deflected at large angles, indicating the positive charge and mass of the atom are concentrated in a tiny nucleus. The nucleus is composed of protons and neutrons, with the number of protons defining the atomic number. Nuclear forces hold the nucleus together despite the repulsive electromagnetic forces between protons. Nuclear fusion and fission can release or absorb large amounts of energy due to the strong binding energy within atomic nuclei.
1) Radioactivity is the spontaneous emission of radiation by unstable atomic nuclei. It occurs as the nucleus shifts to a more stable configuration by emitting energy.
2) The principal factor determining nuclear stability is the neutron-to-proton ratio. No nucleus larger than lead-208 is stable as the strong force cannot overcome electrostatic repulsion at larger sizes.
3) The rate of radioactive decay is proportional to the number of nuclei present and follows an exponential decay model expressed as N(t)=N0e-λt, where λ is the decay constant and N0 is the initial number of nuclei.
Effect of calcination on the electrical properties and quantum confinement of...eSAT Publishing House
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Study of properties for ca (a, n)ti reactions and n yield for ca isotopes (a=41-50)
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35
Study of Properties for Ca (a, n)Ti Reactions and n-Yield for Ca
Isotopes (A=41-50)
Raafat Abdul H. Muslim1*
Khalid H. Mahdi2
Sameera A. Ebrahiem3
1-Ministry of Education, D.G of Currculum, Iraq
2,3- Physics Department, College of Ibn Al-Haytham, University of Baghdad
* E-mail of the corresponding author: raafat.fatla@yahoo.com
Abstract:
In this study, (44
Ti – 53
Ti) isotopes for one of intermediate elements (A>40) from Ca (α, n)Ti reactions with alpha
energy from (10 to 50) MeV are used according to the available data of reaction cross sections obtained from Lab
(TENDL-2012). The more recent cross sections data of Ca (α, n)Ti reaction is reproduced in fine steps of (0.5MeV),
by using (MATLAB R2008b) program. These cross sections together with the stopping powers which calculated
from the Zeigler formula by using SRIM-2013 have been used to calculate the n-yield for reaction by depend on Ca
isotopes (41
Ca – 50
Ca) as targets, and then clarify the behavior between the energies which corresponding to these
cross sections and neutron yield for isotopes, and then we drowned the relationship between the n-yield for these
reactions and symmetry at these energies. Was obtained on mathematical formulas and find constants those
equations and these equations were calculated yield neutron and comparing with theoretical values also studying the
properties of these isotopes, calculated binding energy and reduced mass and also were calculated Q- value and
threshold energy for each reaction and the relative abundance of the isotopes of entering and leaving for alpha
reactions. And then drawing scheduled and discusses the results.
Keyword: Binding energy, Cross-Section, Neutron Yield, stopping power, Asymmetry and empirical formula.
1-Introduction
The (α, n) gneutron sources with intermediate mass nuclei as a target, it has the high neutron yield. Due to many
advantages of the (α,n)neutron source, such as their simplicity of installation, operation and low price compared to
nuclear reactors, these neutron sources are used in activation analysis [1,2,3], calibration source [4], and industrial
applications [5].
The binding energy can be calculated as the reduction in mass multiplied by the square of the velocity of light (c2
=
931.494013 MeV/u) [6]:
Btot(A,Z)=[ZMP + NMn – ]c2
………………..(1)
Where ( Z and N ) are the number of protons and neutrons, (MH, Mn and ) are three masses of hydrogen atom,
neutrons and nucleus respectively.
μ is the reduced mass calculated from the following equation [7]:
μ= …………….(2)
Where (m1) and (m2) are the atomic masses of the projectile and target nucleus, respectively.
The Q – value of the reaction X(α,n)Y, is defined as the difference between the initial and final rest mass energies
[7]:
Q = [Mx + Mα – (MY + Mn)] c2
……………(3)
Where (Mx , Mα , MY and Mn) represents the atomic masses of the target, incident particles, product nucleus and
outgoing particle, respectively. From conservation law of energy [7].
The Q- value is positive, Q > 0, the reaction is said to be (exoergic) or (exothermic).
When Q- value is negative, Q < 0, the reaction is (endoergic) or (endothermic). For (exoergic) reactions, threshold
energy is (zero) and for (endoergic) reactions, the threshold energy is given by [8]:
Ethr = - Q0 (1+ ) ………………..(4)
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Sn = 931.5 [ My + Mn - Mx] ………………..(5)
Where Sn is separation energies of neutron [7].
2- Cross section of the nuclear reaction
To characterize the probability that a certain nuclear reaction will take place, it is customary to define an effective
size of the nucleus for that reaction, called a cross section [7]. The reaction cross section data provides information of
fundamental importance in the study of nuclear systems. The cross section is defined by [9]:
= R / I ……………….. (6)
Were R is the number of reactions per unit time per nucleus. I is the number of incident particles per unit time per
unit area,
The cross section has the units of area and is of the order of the square of nuclear radius. A commonly used unit is
the barn: (1 barn = 10-24
cm2
)
In general, a given bombarding particle and target can react in a variety of ways producing a variety of light reaction
products per unit time. The total cross section is then defined as [10]:
i itot ------- (7)
Where σ i is the partial cross section for the process.
3-Asymmetry energy:
The nuclear asymmetry energy, which is defined as the difference in energy per nucleon between the pure neutron
matter and the symmetric nuclear matter, Asymmetry energy expresses the trend to particular stability of nuclei with
N = Z for small A. Light nuclei become less stable if |N − Z| increases[7]. If we were to add more neutrons, they will
have to be more energetic, thus increasing the total energy of the nucleus, so that it is more favorable to have an
approximately equal number of protons and neutrons. The shape of the asymmetry term is [11]:
(ES = (A − 2Z)2
/A) ……… (8)
It can be more easily understood by considering the fact that this term A goes to zero for A = 2Z and its effect is
smaller for larger (A). Where N is the neutron number, Z is atomic number and A is the mass number.
4-Stopping power:
Many different names have been used for the quantity dE/dX names like energy loss, specific energy loss,
differential energy loss, or stopping power. The stopping power dE/dX, defined as the energy lost by the incident
particles per unit path length, total stopping power (St) is the sum of the electronic stopping power (Se), due to
inelastic interaction with the target electrons, and the nuclear stopping power (Sn) induced by elastic collisions
between the projectiles and the target nucleus[12].
If the energy per atomic mass unit E/M of the incident particles is high, the nuclear contribution compared to the
electronic one is negligible, that mean Nuclear stopping is only important at incident energies E < 100 keV, at higher
energies nuclear stopping becomes negligible so St = Se [12,13].
4-1- Electron Stopping: The electronic stopping of α in elements is derived from the stopping power of protons
for the same velocity by using[14]:
is the alpha charge(α) and can be obtained from the simple polynomial fit.
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37
[ ∑ ]
With E represent alpha energy in keV/amu. is coefficient. Note can be converted to units of MeV/(mg/cm2
) by
multiplying by 0.6022/M2
.
4-2- Nuclear Stopping: The energy loss of the incident ion per unit Length depends on the ion energy. The
nuclear energy loss is small at very high energies, because fast particle have less interaction time with the scattering
nucleus. Thus the nuclear energy loss tends to dominant towards the end of the range when ion has lost much of its
energy, And The nuclear stopping in eV/1015
atoms/cm2 for He-ions with incident energy E (in keV) is given
by[15]:
( )
Where , refer to the ion and , =substrate atom mass and atomic number. And the reduced ion energy , is
defined as:
For >30 keV, unscreened nuclear stopping is used, and simplifies to
5- Neutron Yields:
The Yield of neutron (Y) detected per incident particle (alpha), for an ideal, thin, and uniform target and
monoenergetic particles beam of incident energy Eb is given by [16].
Where n: is the number of target atoms per unit volume, t is the target thickness, σ is the reaction cross section, is
the alpha-detection efficiency. If the target is sufficiently thick, and there exist one atom per each molecule and
taking the efficiency =1, then the resulting alpha yield is called the thick-target yield which is given by [17,18].
∫
σ
⁄
Where, N is the atomic number of target per unit volume, which is defined as follows:
Where, w is the abundant in the combination, is the combination density, A is the mass number, NA is the
Avogadro's number, σ is the cross section, dE/dX is the incident particle initial energy. For natural elements and
if only one stable isotope is available in nature, then [19]
Yo = Y(E) ------ (18)
where (Yo) is the neutron yield per 106
bombarding particle for the natural element.
6- Results and Discussion:
The target (Calcium) has 24 isotopes, which are 34
Ca to 57
Ca. For this study (41
Ca - 50
Ca) that have four stable
isotopes of observations (42
Ca, 43
Ca, 44
Ca and 46
Ca) table (1), in addition to isotope (48
Ca) with the long half-life that
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38
for all practical purposes it can be considered stable as well as the rare 46
Ca, are theoretically unstable on energetic
grounds, but their decay has not been observed. Calcium also has a cosmogenic isotope, radioactive 41
Ca, which has
a half-life of 102,000 years. 41
Ca is produced by neutron activation of 40
Ca. 41
Ca has received much attention in
stellar studies because it decays to 41
K, a critical indicator of solar-system anomalies. The most stable artificial
radioisotope is 45
Ca, with a half-life of 163 days [20]. The atomic mass Isotopes of elements (Ca and Ti) mentioned
in this study have been taken [21] to calculate the binding energy are listed in table (1) as well as abundance[22]
,spin ,parity[23] and half life[20] .
Table (1): The atomic mass of isotopes used in the present work and another data.
isotopes
Atomic Mass(amu)
[21]
B.E(MeV)
P.W
Abundance %
[22]
Half-life
[20]
Spin &
Parity [23]
41
Ca 40.96228 352.5606 - 1.02*105
y 7/2-
42
Ca 41.95862 364.0414 0.647 Stable 0+
43
Ca 42.95877 371.9744 0.135 Stable 7/2-
44
Ca 43.95548 383.1057 2.086 Stable 0+
45
Ca 44.95619 390.5206 - 136 d 7/2-
46
Ca 45.95369 400.9152 0.004 Stable 0+
47
Ca 46.95455 408.1917 - 4.536 d 7/2-
48
Ca 47.95253 418.1371 0.187 6e+18 y 0+
49
Ca 48.95567 423.2837 - 8.718 m 3/2-
50
Ca 49.95752 429.6367 - 13.9 s 0+
44
Ti 43.95969 377.835 - 60.2y 0+
45
Ti 44.95813 387.3637 - 3.08056h 7/2-
46
Ti 45.95263 400.5529 8.25 Stable 0+
47
Ti 46.95176 409.4333 7.44 Stable 5/2-
48
Ti 47.94795 421.0601 73.72 Stable 0+
49
Ti 48.94787 429.2026 5.41 Stable 7/2-
50
Ti 49.94479 440.142 5.18 Stable 0+
51
Ti 50.94661 446.5146 - 5.767m 3/2-
52
Ti 51.9469 454.323 - 1.67m 0+
53
Ti 52.94973 459.7584 - 32.7s 3/2-
We explain same properties of Ca(p,n)Ti reactions from calculated banding energy (BE), Q-value (Q),
reduced mass (μ), threshold energy (Ethr) and separation energies of neutron (n), and we lasted in Table
(2), from this tables we found that same of this reactions are exoergic and the others are endoergic, in
addition to other characteristics.
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Table (2): Calculated results for Ca(α,n)Ti reactions
Reaction
Type
Q – value
(MeV)
P.W
threshold energy
(MeV)
P.W
reduced mass
(amu)
P.W
separation energies
(MeV)
P.W
41
Ca(a,n)44
Ti 377.835 3.55327 3.646306 8.362935
42
Ca(a,n)45
Ti 387.3637 5.684025 3.654029 11.48078
43
Ca(a,n)46
Ti 400.5529 0.073388 3.661453 7.933008
44
Ca(a,n)47
Ti 409.4333 2.382606 3.668543 11.13131
45
Ca(a,n)48
Ti 421.0601 2.208718 3.675371 7.414908
46
Ca(a,n)49
Ti 429.2026 0.243427 3.681905 10.39459
47
Ca(a,n)50
Ti 440.142 3.732079 3.688204 7.276487
48
Ca(a,n)51
Ti 446.5146 0.14511 3.694243 9.945467
49
Ca(a,n)52
Ti 454.323 2.734626 3.700084 5.146565
50
Ca(a,n)53
Ti 459.7584 1.739391 3.705701 6.353007
The cross-section of Ca(α,n)Ti reactions for isotopes (44
Ti - 53
Ti) available in the literatures Labs (TENDL-2012)[24]
has been taken into consideration and re-plotted, interpolated and analyzed by using the MATLAB computer
program to obtain the cross-section for energy range (10 - 50) MeV in fine steps of (0.5MeV) as shown in figure (1).
Figure (1): Cross sections of Ca(α,n)Ti reactions for Ti isotopes
(44
Ti-53
Ti) after interpolation
We note from this figure that the best area of stability for the probability interaction involving all the curves start at
energy approximately 15MeV (solid line) to 50MeV, an area that we have adopted for the calculations to get best
results. After that, and depending on the energies of the incident Alpha and the targets of calcium isotopes ( A= 41-
50 ) and using the program ( SRIM 2013) [25] was calculated stopping power at these energies . It is the ability of
the stopping power with cross-sections at corresponding energies we calculated the neutron yields (n/106
d)
theoretically, shown in figure (2).
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Figure (2): The neutron yield of Ca(α,n)Ti reaction at energy rang (10-50)MeV
for Ca mass number (41-50)
We know increasing the mass number with proven atomic number for calcium isotopes that meaning an increase in
the number of neutrons and the result will directly affect in the asymmetry energy , which was calculated for
calcium isotopes , which we used to extract the empirical formula between the mass number and neutron yield
shown in figure (3), for the incident Alpha energies (10-15) MeV in fine steps of (5 MeV).
10 15 20 25 30 35 40 45 50
0
2
4
6
8
10
12
14
16
18
20
Alpha Energy (MeV)
NeutronYield(n/106
alpha)
CA(a.n)TI Reaction
CA-41(a,n)TI-44
CA-42(a,n)TI-45
CA-43(a,n)TI-46
CA-44(a,n)TI-47
CA-45(a,n)TI-48
CA-46(a,n)TI-49
CA-47(a,n)TI-50
CA-48(a,n)TI-51
CA-49(a,n)TI-52
CA-50(a,n)TI-53
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Fig (3).The neutron yield with asymmetry of Ca target isotopes for different
Alpha energy induced reactions at (10 – 50) MeV
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And the formula that was extracted by fitted for all these curves:
Where Y represent neutron yield. Es represent asymmetry energy. α, β and ɣ represents the first coefficients by
different values for each energy as shown in Table (3).
Table (3) :Primary coefficients at different incident alpha energies when fitted curve between yield and asymmetry
to get find coefficients
Alpha energy(MeV) Α β Γ
10 5.847246 1.02E-01 1.13795
15 7.72E+01 6.27E-02 9.83E-01
20 9.68E+01 6.11E-02 8.48E-01
25 1.01E+02 6.40E-02 8.24E-01
30 1.02E+02 6.71E-02 8.13E-01
35 1.02E+02 6.93E-02 8.05E-01
40 1.02E+02 7.08E-02 7.99E-01
45 1.02E+02 7.19E-02 7.95E-01
50 1.02E+02 7.27E-02 7.92E-01
From this table we draw the relationship between energy and the different values for each coefficient, the fitted
expressions for each coefficient give us following formulas:
And gives the following values of parameters: [ B1 = -2443.5, B2 = -0.30519, B3 = 102.46, B4=0.97403*10-04
,
B5 = 0.9665, B6 = -0.5926, B7 = -0.27937, B8 = -0.05020, B9 = 0.8961345, B10 = 1.49268, B11 = -
0.03539].
We have obtained formula of a set of Ca(α,n)Ti reactions has been used to calculate the neutron yields for each Ca
isotopes at energy rang between (15 – 50) MeV and compared with the adopted neutron yields calculated from the
fitting expressions and shown to be in a good agreement, the comparison of result shown in table (4)
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50 0.85331 0.857622 0.505349 50 0.89588 0.897691 0.202153
Energy = 45 MeV Energy = 50 MeV
Mass number
Yield
Theory
Yield
P.W
Error
%
Mass number
Yield
theory
Yield
P.W
Error
%
41 4.01701 5.007862 24.6664 41 4.06912 5.08692 25.01279
42 13.1233 12.26031 6.57599 42 13.24044 12.38518 6.459445
43 16.90252 16.98211 0.470853 43 17.03839 17.10627 0.398389
44 18.00729 17.55157 2.530756 44 18.13329 17.65094 2.660052
45 12.88477 14.83611 15.14458 45 13.00449 14.90661 14.62666
46 12.39539 10.72159 13.50343 46 12.49965 10.76838 13.85052
47 6.39549 6.796473 6.269779 47 6.49844 6.826232 5.044161
48 4.44348 3.847073 13.42207 48 4.49111 3.865223 13.93613
49 1.34276 1.968185 46.57755 49 1.37101 1.97868 44.32277
50 0.92646 0.919597 0.740821 50 0.94905 0.925284 2.504209
The comparison shows that the calculated results are in agreement to the behavior of the theoretical curve range,
there is a simple systematic deviation as shown in Figure (4) for all Ca isotopes at different energy.
41 42 43 44 45 46 47 48 49 50
0
2
4
6
8
10
12
Mass number
Yield(n/10
6
alphas)
Alpha Energy 15 MeV
theoretically
P.W
41 42 43 44 45 46 47 48 49 50
0
2
4
6
8
10
12
14
16
Mass number
Yield(n/10
6
alphas)
Alpha Energy 20 MeV
theoretically
P.W
41 42 43 44 45 46 47 48 49 50
0
5
10
15
20
Mass number
Yield(n/10
6
alphas)
Alpha Energy 25 MeV
theoretically
P.W
41 42 43 44 45 46 47 48 49 50
0
5
10
15
20
Mass number
Yield(n/10
6
alphas)
Alpha Energy 30 MeV
theoretically
P.W
11. Advances in Physics Theories and Applications www.iiste.org
ISSN 2224-719X (Paper) ISSN 2225-0638 (Online)
Vol.33, 2014
45
Figure (4): The comparison between neutron yields calculated from the theoretically
relationship and fitting expressions for Ca(a,n)Ti
The reason of the deviation is the large interval of long energy rang. It is noted that the neutron yield for energies
between (10-14) was not included with the rest of the table because of the big difference between the theoretical
values and the calculated values from empirical formula, this reason was determined the area of energy in the figure
(1) at the beginning of the work.
Reference :
[1] Kakavand, T.; Haji-Shafeieha, M. and Ghafourian, H.; (2009). “study of neutron yield for the 241
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41 42 43 44 45 46 47 48 49 50
0
5
10
15
20
Mass number
Yield(n/10
6
alphas)
Alpha Energy 35 MeV
theoretically
P.W
41 42 43 44 45 46 47 48 49 50
0
5
10
15
20
Mass number
Yield(n/10
6
alphas)
Alpha Energy 40 MeV
theoretically
P.W
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0
5
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15
20
Mass number
Yield(n/10
6
alphas)
Alpha Energy 45 MeV
theoretically
P.W
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0
5
10
15
20
Mass numberYield(n/10
6
alphas)
Alpha Energy 50 MeV
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Vol.33, 2014
46
[11] Paola, C.; (2012). ” introduction to applied nuclear physics”, Nuclear Science and Engineering Department ,
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