*Helmut Hofmann*

- Published in print:
- 2008
- Published Online:
- September 2008
- ISBN:
- 9780198504016
- eISBN:
- 9780191708480
- Item type:
- book

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198504016.001.0001
- Subject:
- Physics, Nuclear and Plasma Physics

This book offers a survey of nuclear physics at low energies and discusses similarities to mesoscopic systems. It addresses systems at finite excitations of the internal degrees of freedom where ...
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This book offers a survey of nuclear physics at low energies and discusses similarities to mesoscopic systems. It addresses systems at finite excitations of the internal degrees of freedom where collective motion exhibits features typical of transport processes for small and isolated systems. The importance of quantum aspects is investigated both with respect to the microscopic damping mechanism and to the nature of the transport equations. It is vital to account for nuclear collective motion being self-sustained, which in the end implies a highly nonlinear coupling between internal and collective degrees of freedom, a feature which in the literature all too often is ignored. The book is to be considered self-contained. The first part introduces basic elements of nuclear physics and guides to a modern understanding of collective motion as a transport process. This overview is supplemented in the second part with more advanced approaches to nuclear dynamics. The third part deals with special aspects of mesoscopic systems for which close analogies with nuclear physics are given. In the fourth part, the theoretical tools are discussed in greater detail. These include nuclear reaction theory, thermostatics and statistical mechanics, linear response theory, functional integrals, and various aspects of transport theory.Less

This book offers a survey of nuclear physics at low energies and discusses similarities to mesoscopic systems. It addresses systems at finite excitations of the internal degrees of freedom where collective motion exhibits features typical of transport processes for small and isolated systems. The importance of quantum aspects is investigated both with respect to the microscopic damping mechanism and to the nature of the transport equations. It is vital to account for nuclear collective motion being self-sustained, which in the end implies a highly nonlinear coupling between internal and collective degrees of freedom, a feature which in the literature all too often is ignored. The book is to be considered self-contained. The first part introduces basic elements of nuclear physics and guides to a modern understanding of collective motion as a transport process. This overview is supplemented in the second part with more advanced approaches to nuclear dynamics. The third part deals with special aspects of mesoscopic systems for which close analogies with nuclear physics are given. In the fourth part, the theoretical tools are discussed in greater detail. These include nuclear reaction theory, thermostatics and statistical mechanics, linear response theory, functional integrals, and various aspects of transport theory.

*Helmut Hofmann*

- Published in print:
- 2008
- Published Online:
- September 2008
- ISBN:
- 9780198504016
- eISBN:
- 9780191708480
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198504016.003.0022
- Subject:
- Physics, Nuclear and Plasma Physics

This chapter presents the basic elements of statistical mechanics, and derives differential laws of thermostatics of deformed nuclei. Adiabatic and isothermal susceptibilities are introduced. Density ...
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This chapter presents the basic elements of statistical mechanics, and derives differential laws of thermostatics of deformed nuclei. Adiabatic and isothermal susceptibilities are introduced. Density operators for generalized ensembles are defined, from which various extremal properties are deduced, together with the second law and the meaning of quasi-static processes. Level densities and energy distributions are discussed, for which the Darwin-Fowler procedure and Gaussian approximations are introduced, respectively. Such methods allow for simple but realistic estimates of fluctuations of energy and temperature, and thus help to understand the applicability of the canonical ensemble to nuclei as isolated and self-bound systems. This property reflects itself in inherent uncertainties in the value of temperature, as expressed most clearly by a thermal uncertainty relation. Likewise, there is the obvious lack of extensivity, which is believed to lead to negative specific heats. A critical review upon these issues is given. Finally, general formulas for thermostatic potentials of independent particles are derived.Less

This chapter presents the basic elements of statistical mechanics, and derives differential laws of thermostatics of deformed nuclei. Adiabatic and isothermal susceptibilities are introduced. Density operators for generalized ensembles are defined, from which various extremal properties are deduced, together with the second law and the meaning of quasi-static processes. Level densities and energy distributions are discussed, for which the Darwin-Fowler procedure and Gaussian approximations are introduced, respectively. Such methods allow for simple but realistic estimates of fluctuations of energy and temperature, and thus help to understand the applicability of the canonical ensemble to nuclei as isolated and self-bound systems. This property reflects itself in inherent uncertainties in the value of temperature, as expressed most clearly by a thermal uncertainty relation. Likewise, there is the obvious lack of extensivity, which is believed to lead to negative specific heats. A critical review upon these issues is given. Finally, general formulas for thermostatic potentials of independent particles are derived.