“Super Heavy Elements and Nuclei” Krzysztof P
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The R-Process Nucleosynthesis and Related Challenges
EPJ Web of Conferences 165, 01025 (2017) DOI: 10.1051/epjconf/201716501025 NPA8 2017 The r-process nucleosynthesis and related challenges Stephane Goriely1,, Andreas Bauswein2, Hans-Thomas Janka3, Oliver Just4, and Else Pllumbi3 1Institut d’Astronomie et d’Astrophysique, Université Libre de Bruxelles, CP 226, 1050 Brussels, Belgium 2Heidelberger Institut fr¨ Theoretische Studien, Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany 3Max-Planck-Institut für Astrophysik, Postfach 1317, 85741 Garching, Germany 4Astrophysical Big Bang Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan Abstract. The rapid neutron-capture process, or r-process, is known to be of fundamental importance for explaining the origin of approximately half of the A > 60 stable nuclei observed in nature. Recently, special attention has been paid to neutron star (NS) mergers following the confirmation by hydrodynamic simulations that a non-negligible amount of matter can be ejected and by nucleosynthesis calculations combined with the predicted astrophysical event rate that such a site can account for the majority of r-material in our Galaxy. We show here that the combined contribution of both the dynamical (prompt) ejecta expelled during binary NS or NS-black hole (BH) mergers and the neutrino and viscously driven outflows generated during the post-merger remnant evolution of relic BH-torus systems can lead to the production of r-process elements from mass number A > 90 up to actinides. The corresponding abundance distribution is found to reproduce the∼ solar distribution extremely well. It can also account for the elemental distributions observed in low-metallicity stars. However, major uncertainties still affect our under- standing of the composition of the ejected matter. -
The Oganesson Odyssey Kit Chapman Explores the Voyage to the Discovery of Element 118, the Pioneer Chemist It Is Named After, and False Claims Made Along the Way
in your element The oganesson odyssey Kit Chapman explores the voyage to the discovery of element 118, the pioneer chemist it is named after, and false claims made along the way. aving an element named after you Ninov had been dismissed from Berkeley for is incredibly rare. In fact, to be scientific misconduct in May5, and had filed Hhonoured in this manner during a grievance procedure6. your lifetime has only happened to Today, the discovery of the last element two scientists — Glenn Seaborg and of the periodic table as we know it is Yuri Oganessian. Yet, on meeting Oganessian undisputed, but its structure and properties it seems fitting. A colleague of his once remain a mystery. No chemistry has been told me that when he first arrived in the performed on this radioactive giant: 294Og halls of Oganessian’s programme at the has a half-life of less than a millisecond Joint Institute for Nuclear Research (JINR) before it succumbs to α -decay. in Dubna, Russia, it was unlike anything Theoretical models however suggest it he’d ever experienced. Forget the 2,000 ton may not conform to the periodic trends. As magnets, the beam lines and the brand new a noble gas, you would expect oganesson cyclotron being installed designed to hunt to have closed valence shells, ending with for elements 119 and 120, the difference a filled 7s27p6 configuration. But in 2017, a was Oganessian: “When you come to work US–New Zealand collaboration predicted for Yuri, it’s not like a lab,” he explained. that isn’t the case7. -
Photofission Cross Sections of 238U and 235U from 5.0 Mev to 8.0 Mev Robert Andrew Anderl Iowa State University
Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1972 Photofission cross sections of 238U and 235U from 5.0 MeV to 8.0 MeV Robert Andrew Anderl Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Nuclear Commons, and the Oil, Gas, and Energy Commons Recommended Citation Anderl, Robert Andrew, "Photofission cross sections of 238U and 235U from 5.0 MeV to 8.0 MeV " (1972). Retrospective Theses and Dissertations. 4715. https://lib.dr.iastate.edu/rtd/4715 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS This dissertation was produced from a microfilm copy of the original document. While the most advanced technological means to photograph and reproduce this document have been used, the quality is heavily dependent upon the quality of the original submitted. The following explanation of techniques is provided to help you understand markings or patterns which may appear on this reproduction, 1. The sign or "target" for pages apparently lacking from the document photographed is "Missing Page(s)". If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting thru an image and duplicating adjacent pages to insure you complete continuity, 2. -
1 Lecture Notes in Nuclear Structure Physics B. Alex Brown November
1 Lecture Notes in Nuclear Structure Physics B. Alex Brown November 2005 National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy Michigan State University, E. Lansing, MI 48824 CONTENTS 2 Contents 1 Nuclear masses 6 1.1 Masses and binding energies . 6 1.2 Q valuesandseparationenergies . 10 1.3 Theliquid-dropmodel .......................... 18 2 Rms charge radii 25 3 Charge densities and form factors 31 4 Overview of nuclear decays 40 4.1 Decaywidthsandlifetimes. 41 4.2 Alphaandclusterdecay ......................... 42 4.3 Betadecay................................. 51 4.3.1 BetadecayQvalues ....................... 52 4.3.2 Allowedbetadecay ........................ 53 4.3.3 Phase-space for allowed beta decay . 57 4.3.4 Weak-interaction coupling constants . 59 4.3.5 Doublebetadecay ........................ 59 4.4 Gammadecay............................... 61 4.4.1 Reduced transition probabilities for gamma decay . .... 62 4.4.2 Weisskopf units for gamma decay . 65 5 The Fermi gas model 68 6 Overview of the nuclear shell model 71 7 The one-body potential 77 7.1 Generalproperties ............................ 77 7.2 Theharmonic-oscillatorpotential . ... 79 7.3 Separation of intrinsic and center-of-mass motion . ....... 81 7.3.1 Thekineticenergy ........................ 81 7.3.2 Theharmonic-oscillator . 83 8 The Woods-Saxon potential 87 8.1 Generalform ............................... 87 8.2 Computer program for the Woods-Saxon potential . .... 91 8.2.1 Exampleforboundstates . 92 8.2.2 Changingthepotentialparameters . 93 8.2.3 Widthofanunboundstateresonance . 94 8.2.4 Width of an unbound state resonance at a fixed energy . 95 9 The general many-body problem for fermions 97 CONTENTS 3 10 Conserved quantum numbers 101 10.1 Angularmomentum. 101 10.2Parity .................................. -
14. Structure of Nuclei Particle and Nuclear Physics
14. Structure of Nuclei Particle and Nuclear Physics Dr. Tina Potter Dr. Tina Potter 14. Structure of Nuclei 1 In this section... Magic Numbers The Nuclear Shell Model Excited States Dr. Tina Potter 14. Structure of Nuclei 2 Magic Numbers Magic Numbers = 2; 8; 20; 28; 50; 82; 126... Nuclei with a magic number of Z and/or N are particularly stable, e.g. Binding energy per nucleon is large for magic numbers Doubly magic nuclei are especially stable. Dr. Tina Potter 14. Structure of Nuclei 3 Magic Numbers Other notable behaviour includes Greater abundance of isotopes and isotones for magic numbers e.g. Z = 20 has6 stable isotopes (average=2) Z = 50 has 10 stable isotopes (average=4) Odd A nuclei have small quadrupole moments when magic First excited states for magic nuclei higher than neighbours Large energy release in α, β decay when the daughter nucleus is magic Spontaneous neutron emitters have N = magic + 1 Nuclear radius shows only small change with Z, N at magic numbers. etc... etc... Dr. Tina Potter 14. Structure of Nuclei 4 Magic Numbers Analogy with atomic behaviour as electron shells fill. Atomic case - reminder Electrons move independently in central potential V (r) ∼ 1=r (Coulomb field of nucleus). Shells filled progressively according to Pauli exclusion principle. Chemical properties of an atom defined by valence (unpaired) electrons. Energy levels can be obtained (to first order) by solving Schr¨odinger equation for central potential. 1 E = n = principle quantum number n n2 Shell closure gives noble gas atoms. Are magic nuclei analogous to the noble gas atoms? Dr. -
Production and Properties Towards the Island of Stability
This is an electronic reprint of the original article. This reprint may differ from the original in pagination and typographic detail. Author(s): Leino, Matti Title: Production and properties towards the island of stability Year: 2016 Version: Please cite the original version: Leino, M. (2016). Production and properties towards the island of stability. In D. Rudolph (Ed.), Nobel Symposium NS 160 - Chemistry and Physics of Heavy and Superheavy Elements (Article 01002). EDP Sciences. EPJ Web of Conferences, 131. https://doi.org/10.1051/epjconf/201613101002 All material supplied via JYX is protected by copyright and other intellectual property rights, and duplication or sale of all or part of any of the repository collections is not permitted, except that material may be duplicated by you for your research use or educational purposes in electronic or print form. You must obtain permission for any other use. Electronic or print copies may not be offered, whether for sale or otherwise to anyone who is not an authorised user. EPJ Web of Conferences 131, 01002 (2016) DOI: 10.1051/epjconf/201613101002 Nobel Symposium NS160 – Chemistry and Physics of Heavy and Superheavy Elements Production and properties towards the island of stability Matti Leino Department of Physics, University of Jyväskylä, PO Box 35, 40014 University of Jyväskylä, Finland Abstract. The structure of the nuclei of the heaviest elements is discussed with emphasis on single-particle properties as determined by decay and in- beam spectroscopy. The basic features of production of these nuclei using fusion evaporation reactions will also be discussed. 1. Introduction In this short review, some examples of nuclear structure physics and experimental methods relevant for the study of the heaviest elements will be presented. -
Lecture 3: Nuclear Structure 1 • Why Structure? • the Nuclear Potential • Schematic Shell Model
Lecture 3: Nuclear Structure 1 • Why structure? • The nuclear potential • Schematic shell model Lecture 3: Ohio University PHYS7501, Fall 2017, Z. Meisel ([email protected]) Empirically, several striking trends related to Z,N. e.g. B.A. Brown, Lecture Notes in Nuclear Structure Physics, 2005. M.A. Preston, Physics of the Nucleus (1962) Q B.A. Brown, Lecture Notes in Nuclear Structure Physics, 2005. Adapted from B.A. Brown, C.R. Bronk, & P.E. Hodgson, J. Phys. G (1984) P. Möller et al. ADNDT (2016) Meisel & George, IJMS (2013) A. Cameron, Proc. Astron. Soc. Pac. (1957) First magic number evidence compilation 2 by M. Göppert-Mayer Phys. Rev. 1948 …reminiscent of atomic structure B.A. Brown, Lecture Notes in Nuclear Structure Physics, 2005. hyperphysics hyperphysics 54 3 Shell Structure Atomic Nuclear •Central potential (Coulomb) generated by nucleus •No central object …but each nucleon is interacted on by the other A-1 nucleons and they’re relatively compact together •Electrons are essentially non-interacting •Nucleons interact very strongly …but if nucleons in nucleus were to scatter, Pauli blocking prevents them from scattering into filled orbitals. Scattering into higher-E orbitals is unlikely. i.e. there is no “weak interaction paradox” •Solve the Schrödinger equation for the Coulomb •Can also solve the Schrödinger equation for energy potential and find characteristic (energy levels) shells: levels (shells) …but obviously must be a different shells at 2, 10, 18, 36, 54, 86 potential: shells at 2, 8, 20, 28, 50, 82, 126 …you might be discouraged by points 1 and 2 above, but, remember: If it’s stupid but it works, it isn’t stupid. -
Range of Usefulness of Bethe's Semiempirical Nuclear Mass Formula
RANGE OF ..USEFULNESS OF BETHE' S SEMIEMPIRIC~L NUCLEAR MASS FORMULA by SEKYU OBH A THESIS submitted to OREGON STATE COLLEGE in partial fulfillment or the requirements tor the degree of MASTER OF SCIENCE June 1956 TTPBOTTDI Redacted for Privacy lrrt rtllrt ?rsfirror of finrrtor Ia Ohrr;r ef lrJer Redacted for Privacy Redacted for Privacy 0hrtrurn of tohoot Om0qat OEt ttm Redacted for Privacy Dru of 0rrdnrtr Sohdbl Drta thrrlr tr prrrEtrl %.ifh , 1,,r, ," r*(,-. ttpo{ by Brtty Drvlr ACKNOWLEDGMENT The author wishes to express his sincere appreciation to Dr. G. L. Trigg for his assistance and encouragement, without which this study would not have been concluded. The author also wishes to thank Dr. E. A. Yunker for making facilities available for these calculations• • TABLE OF CONTENTS Page INTRODUCTION 1 NUCLEAR BINDING ENERGIES AND 5 SEMIEMPIRICAL MASS FORMULA RESEARCH PROCEDURE 11 RESULTS 17 CONCLUSION 21 DATA 29 f BIBLIOGRAPHY 37 RANGE OF USEFULNESS OF BETHE'S SEMIEMPIRICAL NUCLEAR MASS FORMULA INTRODUCTION The complicated experimental results on atomic nuclei haYe been defying definite interpretation of the structure of atomic nuclei for a long tfme. Even though Yarious theoretical methods have been suggested, based upon the particular aspects of experimental results, it has been impossible to find a successful theory which suffices to explain the whole observed properties of atomic nuclei. In 1936, Bohr (J, P• 344) proposed the liquid drop model of atomic nuclei to explain the resonance capture process or nuclear reactions. The experimental evidences which support the liquid drop model are as follows: 1. Substantially constant density of nuclei with radius R - R Al/3 - 0 (1) where A is the mass number of the nucleus and R is the constant of proportionality 0 with the value of (1.5! 0.1) x 10-lJcm~ 2. -
Nuclear Physics
Massachusetts Institute of Technology 22.02 INTRODUCTION to APPLIED NUCLEAR PHYSICS Spring 2012 Prof. Paola Cappellaro Nuclear Science and Engineering Department [This page intentionally blank.] 2 Contents 1 Introduction to Nuclear Physics 5 1.1 Basic Concepts ..................................................... 5 1.1.1 Terminology .................................................. 5 1.1.2 Units, dimensions and physical constants .................................. 6 1.1.3 Nuclear Radius ................................................ 6 1.2 Binding energy and Semi-empirical mass formula .................................. 6 1.2.1 Binding energy ................................................. 6 1.2.2 Semi-empirical mass formula ......................................... 7 1.2.3 Line of Stability in the Chart of nuclides ................................... 9 1.3 Radioactive decay ................................................... 11 1.3.1 Alpha decay ................................................... 11 1.3.2 Beta decay ................................................... 13 1.3.3 Gamma decay ................................................. 15 1.3.4 Spontaneous fission ............................................... 15 1.3.5 Branching Ratios ................................................ 15 2 Introduction to Quantum Mechanics 17 2.1 Laws of Quantum Mechanics ............................................. 17 2.2 States, observables and eigenvalues ......................................... 18 2.2.1 Properties of eigenfunctions ......................................... -
CHAPTER 2 the Nucleus and Radioactive Decay
1 CHEMISTRY OF THE EARTH CHAPTER 2 The nucleus and radioactive decay 2.1 The atom and its nucleus An atom is characterized by the total positive charge in its nucleus and the atom’s mass. The positive charge in the nucleus is Ze , where Z is the total number of protons in the nucleus and e is the charge of one proton. The number of protons in an atom, Z, is known as the atomic number and dictates which element an atom represents. The nucleus is also made up of N number of neutrally charged particles of similar mass as the protons. These are called neutrons . The combined number of protons and neutrons, Z+N , is called the atomic mass number A. A specific nuclear species, or nuclide , is denoted by A Z Γ 2.1 where Γ represents the element’s symbol. The subscript Z is often dropped because it is redundant if the element’s symbol is also used. We will soon learn that a mole of protons and a mole of neutrons each have a mass of approximately 1 g, and therefore, the mass of a mole of Z+N should be very close to an integer 1. However, if we look at a periodic table, we will notice that an element’s atomic weight, which is the mass of one mole of its atoms, is rarely close to an integer. For example, Iridium’s atomic weight is 192.22 g/mole. The reason for this discrepancy is that an element’s neutron number N can vary. -
The Quest to Explore the Heaviest Elements Raises Questions About How Far Researchers Can Extend Mendeleev’S Creation
ON THE EDGE OF THE PERIODIC TABLE The quest to explore the heaviest elements raises questions about how far researchers can extend Mendeleev’s creation. BY PHILIP BALL 552 | NATURE | VOL 565 | 31 JANUARY 2019 ©2019 Spri nger Nature Li mited. All ri ghts reserved. ©2019 Spri nger Nature Li mited. All ri ghts reserved. FEATURE NEWS f you wanted to create the world’s next undiscovered element, num- Berkeley or at the Joint Institute for Nuclear Research (JINR) in Dubna, ber 119 in the periodic table, here’s a possible recipe. Take a few Russia — the group that Oganessian leads — it took place in an atmos- milligrams of berkelium, a rare radioactive metal that can be made phere of cold-war competition. In the 1980s, Germany joined the race; I only in specialized nuclear reactors. Bombard the sample with a beam an institute in Darmstadt now named the Helmholtz Center for Heavy of titanium ions, accelerated to around one-tenth the speed of light. Ion Research (GSI) made all the elements between 107 and 112. Keep this up for about a year, and be patient. Very patient. For every The competitive edge of earlier years has waned, says Christoph 10 quintillion (1018) titanium ions that slam into the berkelium target Düllmann, who heads the GSI’s superheavy-elements department: — roughly a year’s worth of beam time — the experiment will probably now, researchers frequently talk to each other and carry out some produce only one atom of element 119. experiments collaboratively. The credit for creating later elements On that rare occasion, a titanium and a berkelium nucleus will collide up to 118 has gone variously, and sometimes jointly, to teams from and merge, the speed of their impact overcoming their electrical repul- sion to create something never before seen on Earth, maybe even in the Universe. -
Periodic Table Expands with Elements Named After Japan, Moscow, Tennessee 1 December 2016
Periodic table expands with elements named after Japan, Moscow, Tennessee 1 December 2016 including nihonium—official symbol Nh—are synthesised in laboratories. All the discovered elements after 104 are synthetic ones produced through laboratory experiments. Tradition dictates that newly discovered elements be named after a place, geographical region, or scientist, according to the International Union of Pure and Applied Chemistry (IUPAC), which made the announcement on the names Wednesday. A joint team of Russian and US scientists named element 115 moscovium—symbol Mc—after the Russian capital, where much of the relevant research was conducted. For similar reasons, they also named element 117 tennessine—symbol Ts—after the US state of Credit: CC0 Public Domain Tennessee. The periodic table got larger Wednesday after four The third one they discovered, element 118, was new elements were officially named and added to named oganesson—symbol Og—in homage to the chart, including 'nihonium'—the first ever to be Russian nuclear physicist Yuri Oganessian, in discovered by Japanese scientists. recognition of his "pioneering contributions" in elements research. The new name for element 113, a highly radioactive element with an extremely short half- North Carolina-based IUPAC said that the names life, comes from Japan's name in were officially accepted after a 5-month public Japanese—'nihon', literally 'the land of the rising review period. sun'. "The names of the new elements reflect the "The element, named for the first time by Japanese realities of our present time," IUPAC president and in Asia, will occupy a place in the periodic Natalia Tarasova said on its website, citing the table—an intellectual asset of mankind," Kosuke "universality of science" as well as "the pivotal role" Morita, who led the team that created the element, of Oganessian.