Neutron Capture Cross Sections of Cadmium Isotopes
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Neutron Interactions and Dosimetry Outline Introduction Tissue
Outline • Neutron dosimetry Neutron Interactions and – Thermal neutrons Dosimetry – Intermediate-energy neutrons – Fast neutrons Chapter 16 • Sources of neutrons • Mixed field dosimetry, paired dosimeters F.A. Attix, Introduction to Radiological • Rem meters Physics and Radiation Dosimetry Introduction Tissue composition • Consider neutron interactions with the majority tissue elements H, O, C, and N, and the resulting absorbed dose • Because of the short ranges of the secondary charged particles that are produced in such interactions, CPE is usually well approximated • Since no bremsstrahlung x-rays are generated, the • The ICRU composition for muscle has been assumed in absorbed dose can be assumed to be equal to the most cases for neutron-dose calculations, lumping the kerma at any point in neutron fields at least up to 1.1% of “other” minor elements together with oxygen to an energy E ~ 20 MeV make a simple four-element (H, O, C, N) composition Neutron kinetic energy Neutron kinetic energy • Neutron fields are divided into three • Thermal neutrons, by definition, have the most probable categories based on their kinetic energy: kinetic energy E=kT=0.025eV at T=20C – Thermal (E<0.5 eV) • Neutrons up to 0.5eV are considered “thermal” due to simplicity of experimental test after they emerge from – Intermediate-energy (0.5 eV<E<10 keV) moderator material – Fast (E>10 keV) • Cadmium ratio test: • Differ by their primary interactions in tissue – Gold foil can be activated through 197Au(n,)198Au interaction and resulting biological effects -
Neutron-Induced Fission Cross Section of 240,242Pu up to En = 3 Mev
Neutron-induced fission cross section of 240;242Pu Paula Salvador-Castineira~ Supervisors: Dr. Franz-Josef Hambsch Dr. Carme Pretel Doctoral dissertation PhD in Nuclear Engineering and Ionizing Radiation Barcelona, September 2014 Curs acadèmic: Acta de qualificació de tesi doctoral Nom i cognoms Programa de doctorat Unitat estructural responsable del programa Resolució del Tribunal Reunit el Tribunal designat a l'efecte, el doctorand / la doctoranda exposa el tema de la seva tesi doctoral titulada __________________________________________________________________________________________ _________________________________________________________________________________________. Acabada la lectura i després de donar resposta a les qüestions formulades pels membres titulars del tribunal, aquest atorga la qualificació: NO APTE APROVAT NOTABLE EXCEL·LENT (Nom, cognoms i signatura) (Nom, cognoms i signatura) President/a Secretari/ària (Nom, cognoms i signatura) (Nom, cognoms i signatura) (Nom, cognoms i signatura) Vocal Vocal Vocal ______________________, _______ d'/de __________________ de _______________ El resultat de l’escrutini dels vots emesos pels membres titulars del tribunal, efectuat per l’Escola de Doctorat, a instància de la Comissió de Doctorat de la UPC, atorga la MENCIÓ CUM LAUDE: SÍ NO (Nom, cognoms i signatura) (Nom, cognoms i signatura) President de la Comissió Permanent de l’Escola de Doctorat Secretària de la Comissió Permanent de l’Escola de Doctorat Barcelona, _______ d'/de ____________________ de _________ Universitat Politecnica` -
Neutron Scattering Facilities in Europe Present Status and Future Perspectives
2 ESFRI Physical Sciences and Engineering Strategy Working Group Neutron Landscape Group Neutron scattering facilities in Europe Present status and future perspectives ESFRI scrIPTa Vol. 1 ESFRI Scripta Volume I Neutron scattering facilities in Europe Present status and future perspectives ESFRI Physical Sciences and Engineering Strategy Working Group Neutron Landscape Group i ESFRI Scripta Volume I Neutron scattering facilities in Europe - Present status and future perspectives Author: ESFRI Physical Sciences and Engineering Strategy Working Group - Neutron Landscape Group Scientific editors: Colin Carlile and Caterina Petrillo Foreword Technical editors: Marina Carpineti and Maddalena Donzelli ESFRI Scripta series will publish documents born out of special studies Cover image: Diffraction pattern from the sugar-binding protein Gal3c with mandated by ESFRI to high level expert groups, when of general interest. lactose bound collected using LADI-III at ILL. Picture credits should be given This first volume reproduces the concluding report of an ad-hoc group to D. Logan (Lund University) and M. Blakeley (ILL) mandated in 2014 by the Physical Science and Engineering Strategy Design: Promoscience srl Work Group (PSE SWG) of ESFRI, to develop a thorough analysis of the European Landscape of Research Infrastructures devoted to Neutron Developed on behalf of the ESFRI - Physical Sciences and Engineering Strategy Scattering, and its evolution in the next decades. ESFRI felt the urgency Working Group by the StR-ESFRI project and with the support of the ESFRI of such analysis, since many reactor-based neutron sources will be closed Secretariat down in the next years due to national decisions, while the European The StR-ESFRI project has received funding from the European Union’s Spallation Source (ESS) in Lund will be fully operative only in the mid Horizon 2020 research and innovation programme under grant agreement or late 2020s. -
Concrete Analysis by Neutron-Capture Gamma Rays Using Californium 252
CONCRETE ANALYSIS BY NEUTRON-CAPTURE GAMMA RAYS USING CALIFORNIUM 252 Dick Duffey, College of Engineering, University of Maryland; Peter F. Wiggins, Naval Systems Engineering Department, U.S. Naval Academy; Frank E. Senftle, U.S. Geological Survey; and A. A. El Kady, United Arab Republic Atomic Energy Establishment, Cairo The feasibility of analyzing concrete and cement by a measurement of the neutron-capture or prompt gamma rays was investigated; a 100-ug californium-252 source was used to supply the neutrons. A lithium drifted germanium crystal detected the capture gamma rays emitted. The capture gamma rays from cement, sand, and 3 coarse aggregates-quartzite gravel, limestone, and diabase--:were studied. Concrete blocks made from these materials were then tested. The capture gamma ray response of the calcium, silicon, and iron in the concrete blocks was in accord with the elements identified in the mix materials. The principal spectral lines used were the 6.42 MeV line of calcium, the 4.93 MeV line of silicon, and the doublet of iron at about 7 .64 MeV. The aluminum line at 7. 72 MeV was ob served in some cases but at a lower intensity with the limited electronic equipment available. This nuclear spectroscopic technique offers a possi ble method of determining the components of sizable concrete samples in a nondestructive, in situ manner. In addition, the neutron-capture gamma ray technique might find application in control of the concrete and cement processes and furnish needed information on production operations and inventories. • FROM THE point of view of the geochemical analyst, concrete may be considered as rock relocated and reformed at the convenience of the engineer. -
PGNAA Neutron Source Moderation Setup Optimization
Submitted to ‘Chinese Physics C PGNAA neutron source moderation setup optimization Zhang Jinzhao1(张金钊)Tuo Xianguo1(庹先国) (1.Chengdu University of Technology Applied Nuclear Techniques in Geoscience Key Laboratory of Sichuan Province,Chengdu 610059,China) Abstract: Monte Carlo simulations were carried out to design a prompt γ-ray neutron activation analysis (PGNAA) thermal neutron output setup using MCNP5 computer code. In these simulations the moderator materials, reflective materials and structure of the PGNAA 252Cf neutrons of thermal neutron output setup were optimized. Results of the calcuations revealed that the thin layer paraffin and the thick layer of heavy water moderated effect is best for 252Cf neutrons spectrum. The new design compared with the conventional neutron source design, the thermal neutron flux and rate were increased by 3.02 times and 3.27 times. Results indicate that the use of this design should increase the neutron flux of prompt gamma-ray neutron activation analysis significantly. Key word: PGNAA; neutron source; thermal neutron; moderation; reflection 1. Introduction study, Monte Carlo calculation was carried out for the Prompt gamma ray neutron activation analysis design of a 252Cf neutron source moderation setup for the (PGNAA) is a rapid, nondestructive, powerful analysis cement samples[7]. The model of Monte Carlo multielemental analysis technique, large samples of some simulation was verified by experiment[8, 9].We improve minor, trace light elements and is used in industrial the thermal neutron source yield rate of 252Cf neutron by control[1-5]. In a PGNAA analysis, the sample nuclear the PGNAA neutron source structure to the design. The composition is determined from prompt gamma rays calculation results for the new design were compared which produced through neutron inelastic scattering and with the previous, example: themal neutron flux rate, fast thermal neutron capture. -
1663-29-Othernuclearreaction.Pdf
it’s not fission or fusion. It’s not alpha, beta, or gamma dosimeter around his neck to track his exposure to radiation decay, nor any other nuclear reaction normally discussed in in the lab. And when he’s not in the lab, he can keep tabs on his an introductory physics textbook. Yet it is responsible for various experiments simultaneously from his office computer the existence of more than two thirds of the elements on the with not one or two but five widescreen monitors—displaying periodic table and is virtually ubiquitous anywhere nuclear graphs and computer codes without a single pixel of unused reactions are taking place—in nuclear reactors, nuclear bombs, space. Data printouts pinned to the wall on the left side of the stellar cores, and supernova explosions. office and techno-scribble densely covering the whiteboard It’s neutron capture, in which a neutron merges with an on the right side testify to a man on a mission: developing, or atomic nucleus. And at first blush, it may even sound deserving at least contributing to, a detailed understanding of complex of its relative obscurity, since neutrons are electrically neutral. atomic nuclei. For that, he’ll need to collect and tabulate a lot For example, add a neutron to carbon’s most common isotope, of cold, hard data. carbon-12, and you just get carbon-13. It’s slightly heavier than Mosby’s primary experimental apparatus for doing this carbon-12, but in terms of how it looks and behaves, the two is the Detector for Advanced Neutron Capture Experiments are essentially identical. -
Concurrent Reduction and Distillation; an Improved Technique for the Recovery and Chemical Refinement of the Isotopes of Cadmium and Zinc*
If I CONCURRENT REDUCTION AND DISTILLATION; AN IMPROVED TECHNIQUE FOR THE RECOVERY AND CHEMICAL REFINEMENT OF THE ISOTOPES OF CADMIUM AND ZINC* H. H. Cardill L. E. McBride LOHF-821046—2 E. W. McDaniel DE83 001931 Operations Division Oak Ridge National Laboratory Oak Ridge, Tennessee 3 7830 .DISCLAIMER • s prepared es an accouni oi WOTk sconsQ'ed by an agency of itie United Slates Cover r "iiit?3 Stilt 65 Gov(?fnft»gn ^ ri(jt ^nv aQcncy Tllf GO* ^or rlny O^ tt^^ir ^rnployut^. TigV MASTER lostifl. ion, apod'aiuj pioiJut;. <y vned nghtv Reference hcein xc any v>t^-'T*t. ^ Dv ^.r^de narno, tf^Oernafk^ mir'ij'iJClureT. or otrierw «d <Jo*^ •nenaalion. or liivONng bv 'Vhe United _^_ . vs and opinions of authors enp'«i«] herein do noi IOM t' irip UnitK* Stales Govefnrneni c a^v agency For presentation at the 11th World Conference of the International Nuclear Target Development Society, October 6-8, 1982, Seattle, Washington. By acceptance of this article, the publisher or recipient acknowledge* the U.S. Govarnment's right to retain a nonaxclusiva, royalty-frtta license in and to any copyright covering tha article. NOTICE P0T09_0£-Jfns,J^SPQRT_JfgE_Il,LESIBLE. I has been reproauce.1 from the best available aopy to pensit the broadest possible avail- ability* *Research sponsored by the Office of Basic Energy Science, U.S. Department of Energy under contract W-7405-eng-26 with the Union Carbide Co rpcration,, DISTRIBUTION OF THIS DOCUMEHT 18 UNLIMITED ' CONCURRENT REDUCTION AND DISTILLATION - AY. IMPROVED TECHNIQUE FOR THE RECOVERY AND CHEMICAL REFINEMENT OF THE ISOTOPES OF CADMIUM AND ZINC H. -
Sonie Applications of Fast Neutron Activation Analysis of Oxygen
S E03000182 CTH-RF- 16-5 Sonie Applications of Fast Neutron Activation Analysis of Oxygen Farshid Owrang )52 Akadenmisk uppsats roir avliiggande~ av ilosofie ficentiatexamen i Reaktorf'ysik vid Chalmer's tekniska hiigskola Examinator: Prof. Imre PiAst Handledare: Dr. Anders Nordlund Granskare: Bitr. prof. G~iran Nyrnan Department of Reactor Physics Chalmers University of Technology G6teborg 2003 ISSN 0281-9775 SOME APPLICATIONS OF FAST NEUTRON ACTIVATION OF OXYGE~'N F~arshid Owrang Chalmers University of Technology Departmlent of Reactor Physics SEP-1-412 96 G~iteborg ABSTRACT In this thesis we focus on applications of neutron activation of oxygen for several purposes: A) measuring the water level in a laboratory tank, B) measuring the water flow in a pipe system set-up, C) analysing the oxygen in combustion products formed in a modern gasoline S engine, and D) measuring on-line the amount of oxygen in bulk liquids. A) Water level measurements. The purpose of this work was to perform radiation based water level measurements, aimed at nuclear reactor vessels, on a laboratory scale. A laboratory water tank was irradiated by fast neutrons from a neutron enerator. The water was activated at different water levels and the water level was decreased. The produced gamma radiation was measured using two detectors at different heights. The results showed that the method is suitable for measurement of water level and that a relatively small experimental set-up can be used for developing methods for water level measurements in real boiling water reactors based on activated oxygen in the water. B) Water flows in pipe. -
KULAGE-DISSERTATION-2013.Pdf
ENCRYPTED NANOPARTICLES FOR SECURITY, COUNTER-INDUSTRIAL ESPIONAGE, AND COUNTERFEITING A Dissertation by ZACHARY ANDREW KULAGE Submitted to the Office of Graduate and Professional Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Chair of Committee, William S. Charlton Committee Members, Sean M. McDeavitt John W. Poston, Sr. Charles M. Folden III Head of Department, Yassin A. Hassan December 2013 Major Subject: Nuclear Engineering Copyright 2013 Zachary Andrew Kulage ABSTRACT Acts of terrorism and the use of explosives raise concerns about what can be done to prevent such acts. From stopping such a threat to preventing the illicit counterfeiting and smuggling of sensitive and proprietary goods, identification tag- gant technology can be applied to identify and interdict materials of a dubious na- ture. This cost effective approach to tag and track materials will find application in both the government and private sectors, particularly in the prevention of corporate espionage. A taggant system was created based on the modification of the natural isotopic vector of cadmium and tellurium to create artificial, unique, and robust identification capabilities. A proof of concept trial was undertaken to ascertain the effectiveness, reliability, and integrity of a system. Stable isotopes were mixed in various combi- nations to alter the isotopic vector and then neutron activation analysis techniques were used to evaluate the quality of the taggants. Two different neutron activation analysis facilities of differing capabilities were employed to test the limitations of the method in detection of trace amounts of taggant material. Testing of the taggant system found that solid phase taggants were capable of producing around 14,000 unique taggants for under $250 each while liquid phase taggants were capable of producing around 2,000 unique taggants for under $50 each. -
STUDY of the NEUTRON and PROTON CAPTURE REACTIONS 10,11B(N, ), 11B(P, ), 14C(P, ), and 15N(P, ) at THERMAL and ASTROPHYSICAL ENERGIES
STUDY OF THE NEUTRON AND PROTON CAPTURE REACTIONS 10,11B(n, ), 11B(p, ), 14C(p, ), AND 15N(p, ) AT THERMAL AND ASTROPHYSICAL ENERGIES SERGEY DUBOVICHENKO*,†, ALBERT DZHAZAIROV-KAKHRAMANOV*,† *V. G. Fessenkov Astrophysical Institute “NCSRT” NSA RK, 050020, Observatory 23, Kamenskoe plato, Almaty, Kazakhstan †Institute of Nuclear Physics CAE MINT RK, 050032, str. Ibragimova 1, Almaty, Kazakhstan *[email protected] †[email protected] We have studied the neutron-capture reactions 10,11B(n, ) and the role of the 11B(n, ) reaction in seeding r-process nucleosynthesis. The possibility of the description of the available experimental data for cross sections of the neutron capture reaction on 10B at thermal and astrophysical energies, taking into account the resonance at 475 keV, was considered within the framework of the modified potential cluster model (MPCM) with forbidden states and accounting for the resonance behavior of the scattering phase shifts. In the framework of the same model the possibility of describing the available experimental data for the total cross sections of the neutron radiative capture on 11B at thermal and astrophysical energies were considered with taking into account the 21 and 430 keV resonances. Description of the available experimental data on the total cross sections and astrophysical S-factor of the radiative proton capture on 11B to the ground state of 12C was treated at astrophysical energies. The possibility of description of the experimental data for the astrophysical S-factor of the radiative proton capture on 14C to the ground state of 15N at astrophysical energies, and the radiative proton capture on 15N at the energies from 50 to 1500 keV was considered in the framework of the MPCM with the classification of the orbital states according to Young tableaux. -
Energy Deposition by Neutrons
22.55 “Principles of Radiation Interactions” Neutrons Classification of neutrons by energy Thermal: E < 1 eV (0.025 eV) Epithermal: 1 eV < E < 10 keV Fast: > 10 keV Neutron sources Neutron energies Reactors neutrons in the few keV to several MeV Fusion reactions 14 MeV Large accelerators Hundreds of MeV Energy Deposition by Neutrons • Neutrons are generated over a wide range of energies by a variety of different processes. • Like photons, neutrons are uncharged and do not interact with orbital electrons. • Neutrons can travel considerable distances through matter without interacting. • Neutrons will interact with atomic nuclei through several mechanisms. o Elastic scatter o Inelastic scatter o Nonelastic scatter o Neutron capture o Spallation • The type of interaction depends on the neutron energy Radiation Interactions: neutrons Page 1 of 8 22.55 “Principles of Radiation Interactions” Cross Sections • Because mass attenuation coefficients, µ/ρ (cm2/g) have dimensions of cm2 in the numerator, they have come to be called “cross sections”. • Cross sections do not represent a physical area, but a probability of an interaction. • Cross sections usually expressed in the unit, barn: (10-24 cm2) • The atomic cross sections can be derived from the mass attenuation coefficient. Photons Cross sections are attenuation coefficients, expressed at the atom level (Probability of interaction per atom) ρ N = atom density (#atoms/cm3) N = N A A A 0 2 σA = atomic cross section (cm /atom) 23 N0 = 6.02 x 10 atoms/mole ρ = g/cm3 µ = N A σ A A = g/mole ρ µ = N σ A 0 A µ N σ ⎛ µ ⎞⎛ A ⎞ 0 A ⎜ ⎟⎜ ⎟ = σ A = ⎜ ⎟⎜ ⎟ ρ A ⎝ ρ ⎠⎝ N 0 ⎠ Radiation Interactions: neutrons Page 2 of 8 22.55 “Principles of Radiation Interactions” Neutron Cross Sections Analogous to photons • Neutrons interact by different mechanisms depending on the neutron energy and the material of the absorber o Scattering • elastic • inelastic o Capture • Each energy loss mechanism has a cross section • Neutron cross sections expressed in barns (1 barn = 10-24 cm2). -
Computing Neutron Capture Rates in Neutron-Degenerate Matter †
universe Article Computing Neutron Capture Rates in Neutron-Degenerate Matter † Bryn Knight and Liliana Caballero * Department of Physics, University of Guelph, Guelph, ON N1G 2W1, Canada; [email protected] * Correspondence: [email protected] † This paper is based on the talk at the 7th International Conference on New Frontiers in Physics (ICNFP 2018), Crete, Greece, 4–12 July 2018. Received: 28 November 2018; Accepted: 16 January 2019; Published: 18 January 2019 Abstract: Neutron captures are likely to occur in the crust of accreting neutron stars (NSs). Their rate depends on the thermodynamic state of neutrons in the crust. At high densities, neutrons are degenerate. We find degeneracy corrections to neutron capture rates off nuclei, using cross sections evaluated with the reaction code TALYS. We numerically integrate the relevant cross sections over the statistical distribution functions of neutrons at thermodynamic conditions present in the NS crust. We compare our results to analytical calculations of these corrections based on a power-law behavior of the cross section. We find that although an analytical integration can simplify the calculation and incorporation of the results for nucleosynthesis networks, there are uncertainties caused by departures of the cross section from the power-law approach at energies close to the neutron chemical potential. These deviations produce non-negligible corrections that can be important in the NS crust. Keywords: neutron capture; neutron stars; degenerate matter; nuclear reactions 1. Introduction X-ray burst and superburst observations are attributed to accreting neutron stars (NSs) (see, e.g., [1,2]). In such a scenario, a NS drags matter from a companion star.