DOCSLIB.ORG

A Study of Nuclear Binding Energy of Magic Number Nuclei and Energy Splitting Considering Independent Particle Shell Model

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Study of Nuclear Binding Energy of Magic Number Nuclei and Energy Splitting Considering Independent Particle Shell Model International Journal of Advanced Scientific Research and Management, Volume 3 Issue 2, Feb 2018. www.ijasrm.com ISSN 2455-6378 A study of Nuclear Binding Energy of Magic Number Nuclei and Energy Splitting considering Independent particle shell model Dipesh Chanda Department of Physics, Siliguri College, Siliguri,West Bengal, India. Pin 734001 Abstract according to the configuration 1s-2s-2p-3s-3p-4s- It is well established about the higher nuclear 3d-4p-5s-4d-5p-6s. binding energies of atoms having magic number Similarly nuclear binding energies are high nuclei compared to their nearest neighbouring compared to their adjacent nuclei when proton nuclei and as a whole. In the present case there will number and or neutron numbers are 2, 4, 8, 20, 50, be a comparative study about the nuclear binding 82, 126. The nuclei having the number of protons energies of highly stable nucleus and the nuclei and or neutrons are called magic nuclei. These having one more or less nucleons using nuclear nuclei are not only highly stable but show addition liquid drop model and independent particle shell some characteristics, which are greater relative model simultaneously. In addition to that, there abundances in nature, greater number of stable would be a try to explain the reason of higher isotopes, the separation energy of one proton or one nuclear binding energies of magic number nuclei neutron very large, probability of capturing a by considering additional s l interactions of neutron is much lower, the energy of first excited nucleons. This s l interaction are considered to states of nuclei is high, the alpha disintegration be much stronger and opposite in sign to the energy is small etc. These unexpected behaviors coupling of electrons in the atom. The can be explained by introducing a nuclear model, interaction is very strong coupling of spin and experimental results also reflects these.. orbital motion of the nucleons in the nucleus of the To explain the properties of the nucleus, various magic number nuclei with negative sign is required nuclear models are proposed. Among these, liquid to confirm energy splitting. drop model is one of the most suitable one to calculate the exact value of nuclear binding energy. Keywords: Magic number nuclei, stable nucleus, In the model the atomic nucleus is assumed to be a independent particle model, coupling small water droplet composed of molecules. The properties like shape, density independent of its volume, short range force, etc. of a nucleus are 1. Introduction analogous to the microscopic depiction of a water drop. According the model, when binding energy From the study of atoms, it is found that when of the nucleus are calculated, different factors like number of electrons in an atom are 2, 10, 18, 36, volume energy/effect, surface energy/effect, 54, 86 show high chemical stability, ionization coulomb energy/effect, asymmetric energy/effect potentials are also high and do not interact with and pairing energy/effect, of a nucleus are assumed other atoms. These are called atomic magic to be the only factors effected the actual binding numbers and chemical stability of these atoms can energy of the nucleus, as a result weizsacker be explained on the basis of electronic closed shells assumed a formula that is called semi empirical and sub-shells according Pauli’s exclusion mass formula. Out of the five factors volume effect principle. He(2), Ne(10), Ar(18), Kr(36), Xe(54), increases the binding energy , whereas the next are the examples of atomic magic numbers. three factors decreases the binging energy and the Electrons are filled in shells and sub-shells last factors increases the value for even- even N and Z, decreases when both N and Z are odd. 106 International Journal of Advanced Scientific Research and Management, Vol. Issue , 2018. www.ijasrm.com ISSN 2455-6378 From the study of quadrupol moments of the 931x[Zmp (A Z)mn M] MeV------------- (2) ground state of magic number nuclei, shows zero Where A=mass number and M= isotopic mass of value i.e. these indicates their spherical shape having closed structure. the nucleus. mp , mn , mass of protons and The single particle nuclear shell model proposed neutrons, are used standard values as from the basic as was found in atoms, where m p = 1.007825u, mn =1.008665u electrons moves independently in a central orbit Using the above formula nuclear binding energy of round the nucleus due to the central Coulomb force magic nuclei as well as for their neighbours can be created by the nucleus. In the model it assumed that calculated. the nucleons are moving independently in a combined force of central and non-central force field. For central field, it is explained as a short- Calculation of Separation energy of neutron Sn range potential. Various forms of potential had and proton S p : used for the calculation of nuclear energy level, Separation energy of a neutron or a proton can be like square well potential and harmonic oscillator treated as the amount of energy required to get free well etc. Three dimensional Schrodinger equation one neutron or a proton from the nucleus. i.e. for harmonic oscillator can be solved using minimum energy required for the separation of one spherical polar coordinates. Hence, achieved eigen neutron or one proton from a nucleus. These can value and eigen vectors. In the eigen vectors two be estimated by the equations parts, one is radial function and other spherical S [m M (Z, A1) M (Z, A)]931 MeV. harmonics. For the non central part, MM.Mayer n n and H.Jensen separately assumed the existence of And nuclear interaction (nuclear spin-orbit S p [mp M(Z 1, A1) M(Z, A)931 MeV coupling interaction). Nuclear spin-orbit coupling -------------- (3) where, mn and m p are the masses interaction is like that the atomic cases but much of neutron and proton, M (Z, A1),M (Z 1, A1) stronger and opposite in sign to the interaction of electrons. From this special property and M (X , A) are the masses of nuclei of one of coupling, energy splitting of shells are created in neutron short, one proton short and the mass of nuclear magic numbers, which are also verified original nuclei. experimentally. Estimation of energy of a shell and splitting 2. Theory ands Calculationl energy: Atomic nucleus is considered as a liquid drop so For the explanation of higher stability of magic binding energies of the highly stable nucleus i.e. nuclei, MM.Mayer and H.Jensen separately magic nuclei and their adjacent nuclei can be assumed the existence of nuclear interaction estimated using semi empirical mass formula. The (nuclear spin-orbit). The interaction is stronger and formula used to calculate binding energy is, opposite sign compared to spin orbit coupling 2 / 3 1/ 3 interactions in atoms. The strong interaction of spin B.E avAbsA ccZ(Z 1) / A --------- and orbital motion of the nucleons in the nucleus in d (A 2Z)2 / A / A3/ 4 the nucleus having opposite sign, is the result of a energy splitting in agreement with the experimental (1), nuclear magic numbers. Spin orbit interaction term where the successive terms are volume is considered to be added to the central potential energy/effect, surface energy, coulomb energy, which is non central and may written in the form asymmetry energy and pairing energy. A and Z are V f (r)(s.l ) ----- (4), where f (r) is the the mass no. and atomic no. of the nucleus and av, ls bs, cc, da, and ð are constants, their values are 15.8, potential function, s and l are spin and orbital 17.8, 0.71, 23.7 and 34 respectively. When A and Z angular momentum vectors, both combine to form both are even ð is positive, it is zero, when any one total angular momentum j . is odd and negative when both are odd. Finally binding energy and binding energy per nucleon for After simplification of cosine law magic nuclei and their neighbours can be j( j 1) l(l 1) s(s 1) (s.l ) and estimated. 2 1 1 Calculation of nuclear binding energy from the jmax l and jmin l 2 2 mass defect: Nuclear binding energy = 107 International Journal of Advanced Scientific Research and Management, Vol. Issue , 2018. www.ijasrm.com ISSN 2455-6378 l (l 1) and Easto Ev are estimated out. Than total binding i.e. (s.l ) j and (s.l ) j min ---- max 2 2 are calculated and binding energy per nucleon are (5) estimated. Next once again binding energy of each Ultimately using equation (5), the spin orbit energy magic number nuclei are calculated using mass splitting of two levels defect, For this calculation equation (2) is utilized. Ultimately binding energy per nucleon is 1 Vsl f (r)(2l 1) ----- (6) determined. 2 For the estimation of separation energies of The equation (6) confirms that the state with neutron and proton equation (3) are used. After that 1 1 j l lies below the state j l . some nuclei are chosen which have one more 2 2 nucleon compared to magic nuclei. Following Hence the nuclear orbit in each shells splits and above mention process and by using equations according energy states these are arrange as 1s1/2 (1), (2) and (3), the different ratios of energy terms, 1p3/2,1p1/2,1d5/2,1d3/2,2s1/2,1f7/2, binding energy, binding energy per nucleon, (two 1f5/2,2p3/2,2p1/2,1g9/2,1g7/2 and so on. different ways) and separation energies of neutron Solving the potential function f (r) ( in the form of and proton are estimated.
Load more

Recommended publications
  • A Suggestion Complementing the Magic Numbers Interpretation of the Nuclear Fission Phenomena
    World Journal of Nuclear Science and Technology, 2018, 8, 11-22 http://www.scirp.org/journal/wjnst ISSN Online: 2161-6809 ISSN Print: 2161-6795 A Suggestion Complementing the Magic Numbers Interpretation of the Nuclear Fission Phenomena Faustino Menegus F. Menegus V. Europa, Bussero, Italy How to cite this paper: Menegus, F. Abstract (2018) A Suggestion Complementing the Magic Numbers Interpretation of the Nu- Ideas, solely related on the nuclear shell model, fail to give an interpretation of clear Fission Phenomena. World Journal of the experimental central role of 54Xe in the asymmetric fission of actinides. Nuclear Science and Technology, 8, 11-22. The same is true for the β-delayed fission of 180Tl to 80Kr and 100Ru. The repre- https://doi.org/10.4236/wjnst.2018.81002 sentation of the natural isotopes, in the Z-Neutron Excess plane, suggests the Received: November 21, 2017 importance of the of the Neutron Excess evolution mode in the fragments of Accepted: January 23, 2018 the asymmetric actinide fission and in the fragments of the β-delayed fission Published: January 26, 2018 of 180Tl. The evolution mode of the Neutron Excess, hinged at Kr and Xe, is Copyright © 2018 by author and directed by the 50 and 82 neutron magic numbers. The present isotope repre- Scientific Research Publishing Inc. sentation offers a frame for the interpretation of the post fission evaporation This work is licensed under the Creative of neutrons, higher for the AL compared to the AH fragments, a tenet in nuc- Commons Attribution International License (CC BY 4.0). lear fission.
    [Show full text]
  • Nuclear Models: Shell Model
    LectureLecture 33 NuclearNuclear models:models: ShellShell modelmodel WS2012/13 : ‚Introduction to Nuclear and Particle Physics ‘, Part I 1 NuclearNuclear modelsmodels Nuclear models Models with strong interaction between Models of non-interacting the nucleons nucleons Liquid drop model Fermi gas model ααα-particle model Optical model Shell model … … Nucleons interact with the nearest Nucleons move freely inside the nucleus: neighbors and practically don‘t move: mean free path λ ~ R A nuclear radius mean free path λ << R A nuclear radius 2 III.III. ShellShell modelmodel 3 ShellShell modelmodel Magic numbers: Nuclides with certain proton and/or neutron numbers are found to be exceptionally stable. These so-called magic numbers are 2, 8, 20, 28, 50, 82, 126 — The doubly magic nuclei: — Nuclei with magic proton or neutron number have an unusually large number of stable or long lived nuclides . — A nucleus with a magic neutron (proton) number requires a lot of energy to separate a neutron (proton) from it. — A nucleus with one more neutron (proton) than a magic number is very easy to separate. — The first exitation level is very high : a lot of energy is needed to excite such nuclei — The doubly magic nuclei have a spherical form Nucleons are arranged into complete shells within the atomic nucleus 4 ExcitationExcitation energyenergy forfor magicm nuclei 5 NuclearNuclear potentialpotential The energy spectrum is defined by the nuclear potential solution of Schrödinger equation for a realistic potential The nuclear force is very short-ranged => the form of the potential follows the density distribution of the nucleons within the nucleus: for very light nuclei (A < 7), the nucleon distribution has Gaussian form (corresponding to a harmonic oscillator potential ) for heavier nuclei it can be parameterised by a Fermi distribution.
    [Show full text]
  • Keynote Address: One Hundred Years of Nuclear Physics – Progress and Prospects
    PRAMANA c Indian Academy of Sciences Vol. 82, No. 4 — journal of April 2014 physics pp. 619–624 Keynote address: One hundred years of nuclear physics – Progress and prospects S KAILAS1,2 1Bhabha Atomic Research Centre, Mumbai 400 085, India 2UM–DAE Centre for Excellence in Basic Sciences, Mumbai 400 098, India E-mail: [email protected] DOI: 10.1007/s12043-014-0710-0; ePublication: 5 April 2014 Abstract. Nuclear physics research is growing on several fronts, along energy and intensity fron- tiers, with exotic projectiles and targets. The nuclear physics facilities under construction and those being planned for the future make the prospects for research in this field very bright. Keywords. Nuclear structure and reactions; nuclear properties; superheavy nuclei. PACS Nos 21.10.–k; 25.70.Jj; 25.70.–z 1. Introduction Nuclear physics research is nearly one hundred years old. Currently, this field of research is progressing [1] broadly in three directions (figure 1): Investigation of nuclei and nuclear matter at high energies and densities; observation of behaviour of nuclei under extreme conditions of temperature, angular momentum and deformation; and production and study of nuclei away from the line of stability. Nuclear physics research began with the investiga- tion of about 300 nuclei. Today, this number has grown many folds, nearly by a factor of ten. In the area of high-energy nuclear physics, some recent phenomena observed have provided interesting connections to other disciplines in physics, e.g. in the heavy-ion collisions at relativistic energies, it has been observed [2] that the hot dense matter formed in the collision behaved like an ideal fluid with the ratio of shear viscosity to entropy being close to 1/4π.
    [Show full text]
  • Arxiv:1904.10318V1 [Nucl-Th] 20 Apr 2019 Ucinltheory
    Nuclear structure investigation of even-even Sn isotopes within the covariant density functional theory Y. EL BASSEM1, M. OULNE2 High Energy Physics and Astrophysics Laboratory, Department of Physics, Faculty of Sciences SEMLALIA, Cadi Ayyad University, P.O.B. 2390, Marrakesh, Morocco. Abstract The current investigation aims to study the ground-state properties of one of the most interesting isotopic chains in the periodic table, 94−168Sn, from the proton drip line to the neutron drip line by using the covariant density functional theory, which is a modern theoretical tool for the description of nuclear structure phenomena. The physical observables of interest include the binding energy, separation energy, two-neutron shell gap, rms-radii for protons and neutrons, pairing energy and quadrupole deformation. The calculations are performed for a wide range of neutron numbers, starting from the proton-rich side up to the neutron-rich one, by using the density- dependent meson-exchange and the density dependent point-coupling effec- tive interactions. The obtained results are discussed and compared with available experimental data and with the already existing results of rela- tivistic Mean Field (RMF) model with NL3 functional. The shape phase transition for Sn isotopic chain is also investigated. A reasonable agreement is found between our calculated results and the available experimental data. Keywords: Ground-state properties, Sn isotopes, covariant density functional theory. arXiv:1904.10318v1 [nucl-th] 20 Apr 2019 1. INTRODUCTION In nuclear
    [Show full text]
  • Three Related Topics on the Periodic Tables of Elements
    Three related topics on the periodic tables of elements Yoshiteru Maeno*, Kouichi Hagino, and Takehiko Ishiguro Department oｆ physics, Kyoto University, Kyoto 606-8502, Japan * [email protected] (The Foundations of Chemistry: received 30 May 2020; accepted 31 July 2020) Abstaract: A large variety of periodic tables of the chemical elements have been proposed. It was Mendeleev who proposed a periodic table based on the extensive periodic law and predicted a number of unknown elements at that time. The periodic table currently used worldwide is of a long form pioneered by Werner in 1905. As the first topic, we describe the work of Pfeiffer (1920), who refined Werner’s work and rearranged the rare-earth elements in a separate table below the main table for convenience. Today’s widely used periodic table essentially inherits Pfeiffer’s arrangements. Although long-form tables more precisely represent electron orbitals around a nucleus, they lose some of the features of Mendeleev’s short-form table to express similarities of chemical properties of elements when forming compounds. As the second topic, we compare various three-dimensional helical periodic tables that resolve some of the shortcomings of the long-form periodic tables in this respect. In particular, we explain how the 3D periodic table “Elementouch” (Maeno 2001), which combines the s- and p-blocks into one tube, can recover features of Mendeleev’s periodic law. Finally we introduce a topic on the recently proposed nuclear periodic table based on the proton magic numbers (Hagino and Maeno 2020). Here, the nuclear shell structure leads to a new arrangement of the elements with the proton magic-number nuclei treated like noble-gas atoms.
    [Show full text]
  • Low-Energy Nuclear Physics Part 2: Low-Energy Nuclear Physics
    BNL-113453-2017-JA White paper on nuclear astrophysics and low-energy nuclear physics Part 2: Low-energy nuclear physics Mark A. Riley, Charlotte Elster, Joe Carlson, Michael P. Carpenter, Richard Casten, Paul Fallon, Alexandra Gade, Carl Gross, Gaute Hagen, Anna C. Hayes, Douglas W. Higinbotham, Calvin R. Howell, Charles J. Horowitz, Kate L. Jones, Filip G. Kondev, Suzanne Lapi, Augusto Macchiavelli, Elizabeth A. McCutchen, Joe Natowitz, Witold Nazarewicz, Thomas Papenbrock, Sanjay Reddy, Martin J. Savage, Guy Savard, Bradley M. Sherrill, Lee G. Sobotka, Mark A. Stoyer, M. Betty Tsang, Kai Vetter, Ingo Wiedenhoever, Alan H. Wuosmaa, Sherry Yennello Submitted to Progress in Particle and Nuclear Physics January 13, 2017 National Nuclear Data Center Brookhaven National Laboratory U.S. Department of Energy USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26) Notice: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No.DE-SC0012704 with the U.S. Department of Energy. The publisher by accepting the manuscript for publication acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or any third party’s use or the results of such use of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights.
    [Show full text]
  • 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.
    [Show full text]
  • Upper Limit in Mendeleev's Periodic Table Element No.155
    AMERICAN RESEARCH PRESS Upper Limit in Mendeleev’s Periodic Table Element No.155 by Albert Khazan Third Edition — 2012 American Research Press Albert Khazan Upper Limit in Mendeleev’s Periodic Table — Element No. 155 Third Edition with some recent amendments contained in new chapters Edited and prefaced by Dmitri Rabounski Editor-in-Chief of Progress in Physics and The Abraham Zelmanov Journal Rehoboth, New Mexico, USA — 2012 — This book can be ordered in a paper bound reprint from: Books on Demand, ProQuest Information and Learning (University of Microfilm International) 300 N. Zeeb Road, P. O. Box 1346, Ann Arbor, MI 48106-1346, USA Tel.: 1-800-521-0600 (Customer Service) http://wwwlib.umi.com/bod/ This book can be ordered on-line from: Publishing Online, Co. (Seattle, Washington State) http://PublishingOnline.com Copyright c Albert Khazan, 2009, 2010, 2012 All rights reserved. Electronic copying, print copying and distribution of this book for non-commercial, academic or individual use can be made by any user without permission or charge. Any part of this book being cited or used howsoever in other publications must acknowledge this publication. No part of this book may be re- produced in any form whatsoever (including storage in any media) for commercial use without the prior permission of the copyright holder. Requests for permission to reproduce any part of this book for commercial use must be addressed to the Author. The Author retains his rights to use this book as a whole or any part of it in any other publications and in any way he sees fit.
    [Show full text]
  • Proton Decay at the Drip-Line Magic Number Z = 82, Corresponding to the Closure of a Major Nuclear Shell
    NEWS AND VIEWS NUCLEAR PHYSICS-------------------------------- case since it has one proton more than the Proton decay at the drip-line magic number Z = 82, corresponding to the closure of a major nuclear shell. In Philip Woods fact the observed proton decay comes from an excited intruder state configura­ WHAT determines whether a nuclear ton decay half-life measurements can be tion formed by the promotion of a proton species exists? For nuclear scientists the used to explore nuclear shell structures in from below the Z=82 shell closure. This answer to this poser is that the species this twilight zone of nuclear existence. decay transition was used to provide should live long enough to be identified The proton drip-line sounds an inter­ unique information on the quantum mix­ and its properties studied. This still begs esting place to visit. So how do we get ing between normal and intruder state the fundamental scientific question of there? The answer is an old one: fusion. configurations in the daughter nucleus. what the ultimate boundaries to nuclear In this case, the fusion of heavy nuclei Following the serendipitous discovery existence are. Work by Davids et al. 1 at produces highly neutron-deficient com­ of nuclear proton decay4 from an excited Argonne National Laboratory in the pound nuclei, which rapidly de-excite by state in 1970, and the first example of United States has pinpointed the remotest boiling off particles and gamma-rays, leav­ ground-state proton decay5 in 1981, there border post to date, with the discovery of ing behind a plethora of highly unstable followed relative lulls in activity.
    [Show full text]
  • Nuclear Magic Numbers: New Features Far from Stability
    Nuclear magic numbers: new features far from stability O. Sorlin1, M.-G. Porquet2 1Grand Acc´el´erateur National d’Ions Lours (GANIL), CEA/DSM - CNRS/IN2P3, B.P. 55027, F-14076 Caen Cedex 5, France 2Centre de Spectrom´etrie Nucl´eaire et de Spectrom´etrie de Masse (CSNSM), CNRS/IN2P3 - Universit´eParis-Sud, Bˆat 104-108, F-91405 Orsay, France May 19, 2008 Abstract The main purpose of the present manuscript is to review the structural evolution along the isotonic and isotopic chains around the ”traditional” magic numbers 8, 20, 28, 50, 82 and 126. The exotic regions of the chart of nuclides have been explored during the three last decades. Then the postulate of permanent magic numbers was definitely abandoned and the reason for these structural mutations has been in turn searched for. General trends in the evolution of shell closures are discussed using complementary experimental information, such as the binding energies of the orbits bounding the shell gaps, the trends of the first collective states of the even-even semi-magic nuclei, and the behavior of certain single-nucleon states. Each section is devoted to a particular magic number. It describes the underlying physics of the shell evolution which is not yet fully understood and indicates future experimental and theoretical challenges. The nuclear mean field embodies various facets of the Nucleon- Nucleon interaction, among which the spin-orbit and tensor terms play decisive roles in the arXiv:0805.2561v1 [nucl-ex] 16 May 2008 shell evolutions. The present review intends to provide experimental constraints to be used for the refinement of theoretical models aiming at a good description of the existing atomic nuclei and at more accurate predictions of hitherto unreachable systems.
    [Show full text]
  • Modern Physics to Which He Did This Observation, Usually to Within About 0.1%
    Chapter 12 NUCLEAR STRUCTURE AND RADIOACTIVITY Radioactive isotopes have proven to be valuable tools for medical diagnosis. The photo shows gamma-ray emission from a man who has been treated with a radioactive element. The radioactivity concentrates in locations where there are active cancer tumors, which show as bright areas in the gamma-ray scan. This patient’s cancer has spread from his prostate gland to several other locations in his body. 370 Chapter 12 | Nuclear Structure and Radioactivity The nucleus lies at the center of the atom, occupying only 10−15 of its volume but providing the electrical force that holds the atom together. Within the nucleus there are Z positive charges. To keep these charges from flying apart, the nuclear force must supply an attraction that overcomes their electrical repulsion. This nuclear force is the strongest of the known forces; it provides nuclear binding energies that are millions of times stronger than atomic binding energies. There are many similarities between atomic structure and nuclear structure, which will make our study of the properties of the nucleus somewhat easier. Nuclei are subject to the laws of quantum physics. They have ground and excited states and emit photons in transitions between the excited states. Just like atomic states, nuclear states can be labeled by their angular momentum. There are, however, two major differences between the study of atomic and nuclear properties. In atomic physics, the electrons experience the force provided by an external agent, the nucleus; in nuclear physics, there is no such external agent. In contrast to atomic physics, in which we can often consider the interactions among the electrons as a perturbation to the primary interaction between electrons and nucleus, in nuclear physics the mutual interaction of the nuclear constituents is just what provides the nuclear force, so we cannot treat this complicated many- body problem as a correction to a single-body problem.
    [Show full text]
  • R-Process Nucleosynthesis: on the Astrophysical Conditions
    r-process nucleosynthesis: on the astrophysical conditions and the impact of nuclear physics input r-Prozess Nukleosynthese: Über die astrophysikalischen Bedingungen und den Einfluss kernphysikalischer Modelle Zur Erlangung des Grades eines Doktors der Naturwissenschaften (Dr. rer. nat.) genehmigte Dissertation von M.Sc. Dirk Martin, geb. in Rüsselsheim Tag der Einreichung: 07.02.2017, Tag der Prüfung: 29.05.2017 1. Gutachten: Prof. Dr. Almudena Arcones Segovia 2. Gutachten: Prof. Dr. Jochen Wambach Fachbereich Physik Institut für Kernphysik Theoretische Astrophysik r-process nucleosynthesis: on the astrophysical conditions and the impact of nuclear physics input r-Prozess Nukleosynthese: Über die astrophysikalischen Bedingungen und den Einfluss kernphysikalis- cher Modelle Genehmigte Dissertation von M.Sc. Dirk Martin, geb. in Rüsselsheim 1. Gutachten: Prof. Dr. Almudena Arcones Segovia 2. Gutachten: Prof. Dr. Jochen Wambach Tag der Einreichung: 07.02.2017 Tag der Prüfung: 29.05.2017 Darmstadt 2017 — D 17 Bitte zitieren Sie dieses Dokument als: URN: urn:nbn:de:tuda-tuprints-63017 URL: http://tuprints.ulb.tu-darmstadt.de/6301 Dieses Dokument wird bereitgestellt von tuprints, E-Publishing-Service der TU Darmstadt http://tuprints.ulb.tu-darmstadt.de [email protected] Die Veröffentlichung steht unter folgender Creative Commons Lizenz: Namensnennung – Keine kommerzielle Nutzung – Keine Bearbeitung 4.0 International https://creativecommons.org/licenses/by-nc-nd/4.0/ Für meine Uroma Helene. Abstract The origin of the heaviest elements in our Universe is an unresolved mystery. We know that half of the elements heavier than iron are created by the rapid neutron capture process (r-process). The r-process requires an ex- tremely neutron-rich environment as well as an explosive scenario.
    [Show full text]