Advances in Nuclear Physics

ISBN-13: 9781461590439 / Angielski / Miękka / 2014 / 462 str.

Michel Baranger; Erich Vogt

Opis

In the present volume and in the preceding one we have stretched our normal pattern of reviews by including articles of more major proportions than any we have published before. As a consequence each of these two vol- umes contains only three review articles. From the beginning of this series it has been our aim, as editors, to achieve variation in the scope, style, and length of individual articles sufficient to match the needs of the individual topic, rather than to restrain the authors within rigid limits. We feel that the two major articles of Vols. 5 and 6 are entirely justified and do not repre- sent unnecessary exuberance on the part of the authors. The article by Michaudon on fission is the first comprehensive account of the developments in this subject, which have placed it in the center of the stage of nuclear physics during the past few years. The discovery of fission isomerism and its dramatic manifestations in the intermediate structure of the neutron cross sections for fissionable isotopes are among the most im- portant and interesting events to occur in nuclear physics. These events came as a surprise, and reaffirmed that the strength of nuclear physics lies in the combination of ingenious experiments with simple ideas.

Spis treści

1: Nuclear Fission.- 1. Introduction.- 2. Conventional Description of the Fission Process: Liquid Drop Model, Channel Theory of Fission.- 2.1. Liquid Drop Model.- 2.2 Fission Barrier Heights.- 2.3 Spontaneous Fission of Nuclei in Their Ground State.- 2.4. Fission Channel Theory of A. Bohr.- 3. Experimental Results Which Cannot Be Explained by Conventional Descriptions of the Fission Process.- 3.1. Fission Isomers.- 3.2. Intermediate Structure in Sub-barrier Fission Cross Sections.- 4. Potential Energy of Strongly Deformed Nuclei. Shell Effects.- 4.1. Existence of Shells at Large Deformations.- 4.2. Influence of Shells on the Binding Energy of the Nucleus.- 4.3. Strutinsky’s Phenomenological Prescription for the Calculation of Shell Effects on the Binding Energy.- 4.4. Types of Potentials Used for Calculation of Shell-Energy Corrections.- 4.5. Fission Barrier Calculations with the Inclusion of Shell-Energy Corrections.- 4.6. Other Approaches to the Study of the Effect of Shells on the Potential Energy of Strongly Deformed Heavy Nuclei.- 5. Some Aspects of the Fission Process for Nuclei Having a Double-Humped Fission Barrier.- 5.1. Fission Isomers.- 5.2. Gross Structure in Some Cross Sections for Near-Threshold Fission Processes.- 5.3. Intermediate Structure in Sub-barrier Fission Cross Sections.- 5.4. Intermediate Structure in the Fission Cross Sections of Fissile Nuclei.- 5.5. Measured and Calculated Fission Barriers.- 6. Conclusion.- Acknowledgments.- References.- 2: The Microscopic Theory of Nuclear Effective Interactions and Operators.- 1. Introduction.- 2. General Theory.- 2.1. Time-Dependent Derivation.- 2.2. Time-Independent Derivation.- 2.3. Brueckner Theory.- 2.4. The Algebraic Approach.- 3. Calculation of the Effective Two-Body Interaction.- 3.1. Perturbation Calculations.- 3.2. Nonperturbative Calculations.- 3.3. Convergence of the Perturbation Expansion.- 3.4. Conclusions.- 4. Calculation of the E2 Effective Charge.- 4.1. Effective Charge in Mass-17 Nuclei.- 4.2. Effects of Nucleon-Nucleon Force and Single-Particle Potential.- 4.3. Other Mass Values.- 5. Discussion and Conclusions.- Acknowledgments.- References.- 3: Two-Neutron Transfer Reactions and the Pairing Mode.- 1. Introduction.- 2. The Reaction Mechanism.- 2.1. The DWBA Method for Two-Nucleon Transfer Reactions.- 2.2. The Two-Nucleon Transfer Form Factor.- 2.3. Discussion of the Form Factor.- 2.4. Comparison Between DW Theory and Experiment.- 2.5. Two-Particle Units and Sum Rules.- 3. Presentation of the Data.- 3.1. The Gross Trends of 0+ ? 0+ and 0+? 2+ Transitions.- 3.2. Nuclei Far from Neutron Shell Closures.- 3.3. The Closed Shell Regions.- 3.4. Subshell Closures.- 4. The Pairing Model and Two-Neutron Transfer Reactions to J? = 0+ States.- 4.1. Pairing Deformed Systems.- 4.2. Normal Systems.- 4.3. The Pairing Phase Transitions.- 5. Analysis of the L = 0 Two-Neutron Transfer Reactions.- 5.1. Systems Far Away from Closed Shells.- 5.2. Systems Near Closed Shells.- 5.3. Intermediate Situations.- 5.4. Limitations of the Pairing Collective Description.- 5.5. Summary.- 6. Two-Neutron Transfer Reactions to States with J ? 0 and Natural Parity.- 6.1. Normal Systems.- 6.2. Superfluid Nuclei.- 6.3. Particle-Vibration Coupling and the Problem of Anharmonicities.- 6.4. Anharmonicities of the Pairing Vibration Spectrum as Determined from (t, p) and (p, t) Reactions.- 6.5. Summary.- Acknowledgments.- Appendix 1.- Data References for the Appendix Tables.- Appendix 2.- A2.1. Introduction.- A2.2. Coexistence Model.- A2.3. SU3 Model.- A2.4. Pairing Model.- Appendix 3.- References.