Roger H. Stuewer
- Published in print:
- 2018
- Published Online:
- September 2018
- ISBN:
- 9780198827870
- eISBN:
- 9780191866586
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780198827870.001.0001
- Subject:
- Physics, History of Physics, Nuclear and Plasma Physics
Nuclear physics emerged as the dominant field in experimental and theoretical physics between 1919 and 1939, the two decades between the First and Second World Wars. Milestones were Ernest ...
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Nuclear physics emerged as the dominant field in experimental and theoretical physics between 1919 and 1939, the two decades between the First and Second World Wars. Milestones were Ernest Rutherford’s discovery of artificial nuclear disintegration (1919), George Gamow’s and Ronald Gurney and Edward Condon’s simultaneous quantum-mechanical theory of alpha decay (1928), Harold Urey’s discovery of deuterium (the deuteron), James Chadwick’s discovery of the neutron, Carl Anderson’s discovery of the positron, John Cockcroft and Ernest Walton’s invention of their eponymous linear accelerator, and Ernest Lawrence’s invention of the cyclotron (1931–2), Frédéric and Irène Joliot-Curie’s discovery and confirmation of artificial radioactivity (1934), Enrico Fermi’s theory of beta decay based on Wolfgang Pauli’s neutrino hypothesis and Fermi’s discovery of the efficacy of slow neutrons in nuclear reactions (1934), Niels Bohr’s theory of the compound nucleus and Gregory Breit and Eugene Wigner’s theory of nucleus+neutron resonances (1936), and Lise Meitner and Otto Robert Frisch’s interpretation of nuclear fission, based on Gamow’s liquid-drop model of the nucleus (1938), which Frisch confirmed experimentally (1939). These achievements reflected the idiosyncratic personalities of the physicists who made them; they were shaped by the physical and intellectual environments of the countries and institutions in which they worked; and they were buffeted by the profound social and political upheavals after the Great War: the punitive postwar treaties, the runaway inflation in Germany and Austria, the Great Depression, and the greatest intellectual migration in history, which encompassed some of the most gifted experimental and theoretical nuclear physicists in the world.Less
Nuclear physics emerged as the dominant field in experimental and theoretical physics between 1919 and 1939, the two decades between the First and Second World Wars. Milestones were Ernest Rutherford’s discovery of artificial nuclear disintegration (1919), George Gamow’s and Ronald Gurney and Edward Condon’s simultaneous quantum-mechanical theory of alpha decay (1928), Harold Urey’s discovery of deuterium (the deuteron), James Chadwick’s discovery of the neutron, Carl Anderson’s discovery of the positron, John Cockcroft and Ernest Walton’s invention of their eponymous linear accelerator, and Ernest Lawrence’s invention of the cyclotron (1931–2), Frédéric and Irène Joliot-Curie’s discovery and confirmation of artificial radioactivity (1934), Enrico Fermi’s theory of beta decay based on Wolfgang Pauli’s neutrino hypothesis and Fermi’s discovery of the efficacy of slow neutrons in nuclear reactions (1934), Niels Bohr’s theory of the compound nucleus and Gregory Breit and Eugene Wigner’s theory of nucleus+neutron resonances (1936), and Lise Meitner and Otto Robert Frisch’s interpretation of nuclear fission, based on Gamow’s liquid-drop model of the nucleus (1938), which Frisch confirmed experimentally (1939). These achievements reflected the idiosyncratic personalities of the physicists who made them; they were shaped by the physical and intellectual environments of the countries and institutions in which they worked; and they were buffeted by the profound social and political upheavals after the Great War: the punitive postwar treaties, the runaway inflation in Germany and Austria, the Great Depression, and the greatest intellectual migration in history, which encompassed some of the most gifted experimental and theoretical nuclear physicists in the world.
Richard Wigmans
- Published in print:
- 2017
- Published Online:
- January 2018
- ISBN:
- 9780198786351
- eISBN:
- 9780191828652
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780198786351.001.0001
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology, Nuclear and Plasma Physics
Particle physics is the science that pursues the age-old quest for the innermost structure of matter and the fundamental interactions between its constituents. Modern experiments in this field rely ...
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Particle physics is the science that pursues the age-old quest for the innermost structure of matter and the fundamental interactions between its constituents. Modern experiments in this field rely increasingly on calorimetry, a detection technique in which the particles of interest are absorbed in the detector. Calorimeters are very intricate instruments, their performance characteristics depend in subtle, sometimes counter-intuitive ways on design details. This book, written by one of the world's foremost experts, is the only comprehensive text on this topic. It provides a fundamental and systematic introduction, in which many intriguing calorimeter features are explained. It also describes the state-of-the-art, both for what concerns the fundamental understanding of calorimetric particle detection and the actual detectors that have been or are being built and operated in experiments. In the last chapter, some landmark scientific discoveries in which calorimetry has played an important role are discussed. This book summarizes and puts in perspective work described in some 900 scientific papers, listed in the bibliography. This second edition emphasizes new developments that have taken place since the the first edition appeared (2000).Less
Particle physics is the science that pursues the age-old quest for the innermost structure of matter and the fundamental interactions between its constituents. Modern experiments in this field rely increasingly on calorimetry, a detection technique in which the particles of interest are absorbed in the detector. Calorimeters are very intricate instruments, their performance characteristics depend in subtle, sometimes counter-intuitive ways on design details. This book, written by one of the world's foremost experts, is the only comprehensive text on this topic. It provides a fundamental and systematic introduction, in which many intriguing calorimeter features are explained. It also describes the state-of-the-art, both for what concerns the fundamental understanding of calorimetric particle detection and the actual detectors that have been or are being built and operated in experiments. In the last chapter, some landmark scientific discoveries in which calorimetry has played an important role are discussed. This book summarizes and puts in perspective work described in some 900 scientific papers, listed in the bibliography. This second edition emphasizes new developments that have taken place since the the first edition appeared (2000).
Karl-Heinz Bennemann and John B. Ketterson
- Published in print:
- 2013
- Published Online:
- May 2013
- ISBN:
- 9780199585915
- eISBN:
- 9780191747526
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199585915.001.0001
- Subject:
- Physics, Nuclear and Plasma Physics
This book reports on the latest developments in the field of superfluidity. The phenomenon has had a tremendous impact on the fundamental sciences as well as a host of technologies. It began with the ...
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This book reports on the latest developments in the field of superfluidity. The phenomenon has had a tremendous impact on the fundamental sciences as well as a host of technologies. It began with the discovery of superconductivity in mercury in 1911, which was ultimately described theoretically by the theory of Bardeen Cooper and Schriever (BCS) in 1957. The analogous phenomena, superfluidity, was discovered in helium in 1938 and tentatively explained shortly thereafter as arising from a Bose–Einstein Condensation by London. But the importance of superfluidity, and the range of systems in which it occurs, has grown enormously. In addition to metals and the helium liquids the phenomena has now been observed for photons in cavities, excitons in semiconductors, magnons in certain materials, and cold gasses trapped in high vacuum. It very likely exist for neutrons in a neutron star and, possibly, in a conjectured quark state at their centre. Even the Universe itself can be regarded as being in a kind of superfluid state. All these topics are discussed by experts in the respective subfields.Less
This book reports on the latest developments in the field of superfluidity. The phenomenon has had a tremendous impact on the fundamental sciences as well as a host of technologies. It began with the discovery of superconductivity in mercury in 1911, which was ultimately described theoretically by the theory of Bardeen Cooper and Schriever (BCS) in 1957. The analogous phenomena, superfluidity, was discovered in helium in 1938 and tentatively explained shortly thereafter as arising from a Bose–Einstein Condensation by London. But the importance of superfluidity, and the range of systems in which it occurs, has grown enormously. In addition to metals and the helium liquids the phenomena has now been observed for photons in cavities, excitons in semiconductors, magnons in certain materials, and cold gasses trapped in high vacuum. It very likely exist for neutrons in a neutron star and, possibly, in a conjectured quark state at their centre. Even the Universe itself can be regarded as being in a kind of superfluid state. All these topics are discussed by experts in the respective subfields.
Kenneth D. McRae
- Published in print:
- 2014
- Published Online:
- May 2014
- ISBN:
- 9780199687183
- eISBN:
- 9780191767029
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199687183.001.0001
- Subject:
- Physics, History of Physics, Nuclear and Plasma Physics
This book is a rounded biography of Franz (later Sir Francis) Simon, his early life in Germany, his move to Oxford in1933, and his experimental contributions to low temperature physics approximating ...
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This book is a rounded biography of Franz (later Sir Francis) Simon, his early life in Germany, his move to Oxford in1933, and his experimental contributions to low temperature physics approximating absolute zero. After 1939 he switched his research to nuclear physics, and is credited with solving the problem of uranium isotope separation by gaseous diffusion for the British nuclear programme Tube Alloys. The volume is distinctive for its inclusion of source materials not available to previous researchers, such as Simon’s diary and his correspondence with his wife, and for a fresh, well informed insider voice on the five-power nuclear rivalry of the war years. The work also draws on a relative mature nuclear literature to attempt a comparison and evaluation of the five nuclear rivals in wider political and military context to identify the factors of groups or factors that can explain the results.Less
This book is a rounded biography of Franz (later Sir Francis) Simon, his early life in Germany, his move to Oxford in1933, and his experimental contributions to low temperature physics approximating absolute zero. After 1939 he switched his research to nuclear physics, and is credited with solving the problem of uranium isotope separation by gaseous diffusion for the British nuclear programme Tube Alloys. The volume is distinctive for its inclusion of source materials not available to previous researchers, such as Simon’s diary and his correspondence with his wife, and for a fresh, well informed insider voice on the five-power nuclear rivalry of the war years. The work also draws on a relative mature nuclear literature to attempt a comparison and evaluation of the five nuclear rivals in wider political and military context to identify the factors of groups or factors that can explain the results.
Richard F. Casten
- Published in print:
- 2001
- Published Online:
- January 2010
- ISBN:
- 9780198507246
- eISBN:
- 9780191709333
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198507246.001.0001
- Subject:
- Physics, Nuclear and Plasma Physics
This textbook on nuclear structure takes a unique and complementary approach compared to existing texts on the topic. Avoiding complicated calculations and complex mathematical formalism, it explains ...
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This textbook on nuclear structure takes a unique and complementary approach compared to existing texts on the topic. Avoiding complicated calculations and complex mathematical formalism, it explains nuclear structure by building on a few elementary physical ideas. Even such apparently intricate topics as shell model residual interactions, the Nilsson model, and the random phase approximation analysis of collective vibrations are explained in a simple, intuitive way so that predictions can usually be made without calculations, essentially by inspection. Frequent comparison with data allows the relevance of theoretical approaches to be immediately evident. This edition includes new chapters on exotic nuclei and radioactive beams, and on correlations of collective observables. Completely new discussions are given of isospin, the shell model, nature of collective vibrations, multi-phonon states, superdeformation, bandmixing, geometric collective model, Fermi gas model, basic properties of simple nuclear potentials, the deuteron, and low energy nuclear structure, as well as other topics.Less
This textbook on nuclear structure takes a unique and complementary approach compared to existing texts on the topic. Avoiding complicated calculations and complex mathematical formalism, it explains nuclear structure by building on a few elementary physical ideas. Even such apparently intricate topics as shell model residual interactions, the Nilsson model, and the random phase approximation analysis of collective vibrations are explained in a simple, intuitive way so that predictions can usually be made without calculations, essentially by inspection. Frequent comparison with data allows the relevance of theoretical approaches to be immediately evident. This edition includes new chapters on exotic nuclei and radioactive beams, and on correlations of collective observables. Completely new discussions are given of isospin, the shell model, nature of collective vibrations, multi-phonon states, superdeformation, bandmixing, geometric collective model, Fermi gas model, basic properties of simple nuclear potentials, the deuteron, and low energy nuclear structure, as well as other topics.
Stefano Atzeni and Jürgen Meyer-ter-Vehn
- Published in print:
- 2004
- Published Online:
- January 2008
- ISBN:
- 9780198562641
- eISBN:
- 9780191714030
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198562641.001.0001
- Subject:
- Physics, Nuclear and Plasma Physics
The book is devoted to targets for nuclear fusion by inertial confinement and to the various branches of physics involved. It first discusses fusion reactions and general requirements for fusion ...
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The book is devoted to targets for nuclear fusion by inertial confinement and to the various branches of physics involved. It first discusses fusion reactions and general requirements for fusion energy production. It then introduces and illustrates the concept of inertial confinement fusion by spherical implosion, followed by detailed treatments of the physics of fusion ignition and burn, and of energy gain. The next part of the book is mostly devoted to the underlying physics involved in inertial fusion, and covers hydrodynamics, hydrodynamic stability, radiative transport and equations-of-state of hot dense matter, laser and ion beam interaction with plasma. It discusses different approaches to inertial fusion (direct-drive by laser, indirect-drive by laser or ion beams), including recent developments in fast ignition. The goal of the book is to give an introduction to this subject, and also to provide practical results even when derived on the basis of simplified models.Less
The book is devoted to targets for nuclear fusion by inertial confinement and to the various branches of physics involved. It first discusses fusion reactions and general requirements for fusion energy production. It then introduces and illustrates the concept of inertial confinement fusion by spherical implosion, followed by detailed treatments of the physics of fusion ignition and burn, and of energy gain. The next part of the book is mostly devoted to the underlying physics involved in inertial fusion, and covers hydrodynamics, hydrodynamic stability, radiative transport and equations-of-state of hot dense matter, laser and ion beam interaction with plasma. It discusses different approaches to inertial fusion (direct-drive by laser, indirect-drive by laser or ion beams), including recent developments in fast ignition. The goal of the book is to give an introduction to this subject, and also to provide practical results even when derived on the basis of simplified models.
Vladimir Fortov, Igor Iakubov, and Alexey Khrapak
- Published in print:
- 2006
- Published Online:
- September 2007
- ISBN:
- 9780199299805
- eISBN:
- 9780191714948
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199299805.001.0001
- Subject:
- Physics, Nuclear and Plasma Physics
This book concerns the physics of plasma at high density, which is compressed so strongly that the effects of interparticle interactions, nonideality, govern its behavior. The interest in this ...
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This book concerns the physics of plasma at high density, which is compressed so strongly that the effects of interparticle interactions, nonideality, govern its behavior. The interest in this non-traditional plasma has emerged during the last few years when states of matter with high concentration of energy, constituting the basis of the modern technologies and facilities, became accessible for impulse experiments. The greatest part of the Universe matter is in this exotic state. In this book, the methods of strongly coupled plasma generation and diagnostics are considered. The experimental results on thermodynamic, kinetic, and optical properties are given, and the main theoretical models of the strongly coupled plasma state are discussed. Particular attention is given to fast developing modern directions of strongly coupled plasma physics, such as metallization of dielectrics and dielectrization of metals, nonneutral plasma, complex (dusty) plasma, and its crystallization.Less
This book concerns the physics of plasma at high density, which is compressed so strongly that the effects of interparticle interactions, nonideality, govern its behavior. The interest in this non-traditional plasma has emerged during the last few years when states of matter with high concentration of energy, constituting the basis of the modern technologies and facilities, became accessible for impulse experiments. The greatest part of the Universe matter is in this exotic state. In this book, the methods of strongly coupled plasma generation and diagnostics are considered. The experimental results on thermodynamic, kinetic, and optical properties are given, and the main theoretical models of the strongly coupled plasma state are discussed. Particular attention is given to fast developing modern directions of strongly coupled plasma physics, such as metallization of dielectrics and dielectrization of metals, nonneutral plasma, complex (dusty) plasma, and its crystallization.
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.
Abraham Bers
- Published in print:
- 2016
- Published Online:
- November 2016
- ISBN:
- 9780199295784
- eISBN:
- 9780191749063
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199295784.001.0001
- Subject:
- Physics, Nuclear and Plasma Physics, Particle Physics / Astrophysics / Cosmology
This book covers collective and single particle dynamics of plasmas for fully ionized as well as partially ionized plasmas. Many aspects of plasma physics in current fusion energy generation research ...
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This book covers collective and single particle dynamics of plasmas for fully ionized as well as partially ionized plasmas. Many aspects of plasma physics in current fusion energy generation research are addressed both in magnetic and inertial confinement plasmas. Linear and nonlinear dynamics in hydrodynamic and kinetic descriptions are exposed so that readers are faced with the simple and complex aspects of the subject in nearly every chapter. The approach of dividing the basic aspects of plasma physics as linear, hydrodynamic descriptions to be covered first and postponing the nonlinear and kinetic description for later is abandoned in this book.Less
This book covers collective and single particle dynamics of plasmas for fully ionized as well as partially ionized plasmas. Many aspects of plasma physics in current fusion energy generation research are addressed both in magnetic and inertial confinement plasmas. Linear and nonlinear dynamics in hydrodynamic and kinetic descriptions are exposed so that readers are faced with the simple and complex aspects of the subject in nearly every chapter. The approach of dividing the basic aspects of plasma physics as linear, hydrodynamic descriptions to be covered first and postponing the nonlinear and kinetic description for later is abandoned in this book.
Takashi Fujimoto
- Published in print:
- 2004
- Published Online:
- September 2007
- ISBN:
- 9780198530282
- eISBN:
- 9780191713149
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198530282.001.0001
- Subject:
- Physics, Nuclear and Plasma Physics
This book presents a theoretical framework of plasma spectroscopy, in which the observed spectral line intensities or the populations of excited levels of atoms or ions immersed in plasma are ...
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This book presents a theoretical framework of plasma spectroscopy, in which the observed spectral line intensities or the populations of excited levels of atoms or ions immersed in plasma are interpreted in terms of the characteristics of the plasma. Following a review of important atomic processes in plasma, the rate equation governing the populations in excited levels and the ground state is solved in the collisional-radiative model. In this model, plasmas are classified into the ionizing plasma and the recombining plasma. Various features of these plasmas are examined. Ionization and recombination of atoms and ions are also treated in the model. An emission-line intensity is proportional to the ionization flux or to the recombination flux, and thus the ionization-balance plasma produces less intense emission lines. The recombination continuum intensity continues smoothly to the series lines, originating from levels in local thermodynamic equilibrium, so that the Boltzmann plot of the population of these levels is extended to the continuum-state electrons. Line broadening mechanisms are discussed, including the Stark broadening. Radiation transport gives rise to a modification to the emission line profile and to an effective decrease in the transition probability; the latter problem is treated in two alternative approaches. Phenomena characteristic of dense plasma are discussed, including the excitation and deexcitation processes of ions involving doubly excited levels and a modification to the Saha relationship.Less
This book presents a theoretical framework of plasma spectroscopy, in which the observed spectral line intensities or the populations of excited levels of atoms or ions immersed in plasma are interpreted in terms of the characteristics of the plasma. Following a review of important atomic processes in plasma, the rate equation governing the populations in excited levels and the ground state is solved in the collisional-radiative model. In this model, plasmas are classified into the ionizing plasma and the recombining plasma. Various features of these plasmas are examined. Ionization and recombination of atoms and ions are also treated in the model. An emission-line intensity is proportional to the ionization flux or to the recombination flux, and thus the ionization-balance plasma produces less intense emission lines. The recombination continuum intensity continues smoothly to the series lines, originating from levels in local thermodynamic equilibrium, so that the Boltzmann plot of the population of these levels is extended to the continuum-state electrons. Line broadening mechanisms are discussed, including the Stark broadening. Radiation transport gives rise to a modification to the emission line profile and to an effective decrease in the transition probability; the latter problem is treated in two alternative approaches. Phenomena characteristic of dense plasma are discussed, including the excitation and deexcitation processes of ions involving doubly excited levels and a modification to the Saha relationship.
Paul T. Callaghan
- Published in print:
- 2011
- Published Online:
- December 2013
- ISBN:
- 9780199556984
- eISBN:
- 9780191774928
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199556984.001.0001
- Subject:
- Physics, Condensed Matter Physics / Materials, Nuclear and Plasma Physics
In 1950, Erwin Hahn pointed out that spin echoes in Nuclear Magnetic Resonance (NMR) could be used to measure molecular translational motion, an effect made possible because nuclear spins carry a ...
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In 1950, Erwin Hahn pointed out that spin echoes in Nuclear Magnetic Resonance (NMR) could be used to measure molecular translational motion, an effect made possible because nuclear spins carry a phase determined by the history of their residence in magnetic fields. If, through our own volition or by consequence of sample structure, magnetic fields can be given some spatial variation, and if the spin-bearing molecules translate, then the spin phases can be made to tell the story of that migration. Unlike modern bio-molecular NMR, the multitude of tricks used to measure molecular translational motion take place without the need for high spectral resolution. They work, with equal power, at low field and in the absence of spectral discrimination, and so lend themselves to that new branch of NMR technology that concerns itself with ‘outside the laboratory’ applications, in geophysics and petroleum physics, in horticulture, in food technology, in security screening and in environmental monitoring. The translational dynamics of molecules provide a signature for molecular size and shape size, the visco-elasticity of the surrounding fluid medium, their organization into supramolecular assemblies, their exchange between different sites, their intermittent binding, their confinement by a surrounding matrix or phase boundary, and the topology of that confinement. This book takes us through the various underlying principles of molecular translational dynamics, outlining the ways in which magnetic resonance, through the use of magnetic field gradients, can reveal those dynamics. It covers the full range of time and Frequency Domain methodologies, showing how they can be used, as well as advances in ‘scattering and diffraction’ methods, multidimensional exchange and correlation experiments, and orientational correlation methods ideal for studying dynamics in anisotropic environments.Less
In 1950, Erwin Hahn pointed out that spin echoes in Nuclear Magnetic Resonance (NMR) could be used to measure molecular translational motion, an effect made possible because nuclear spins carry a phase determined by the history of their residence in magnetic fields. If, through our own volition or by consequence of sample structure, magnetic fields can be given some spatial variation, and if the spin-bearing molecules translate, then the spin phases can be made to tell the story of that migration. Unlike modern bio-molecular NMR, the multitude of tricks used to measure molecular translational motion take place without the need for high spectral resolution. They work, with equal power, at low field and in the absence of spectral discrimination, and so lend themselves to that new branch of NMR technology that concerns itself with ‘outside the laboratory’ applications, in geophysics and petroleum physics, in horticulture, in food technology, in security screening and in environmental monitoring. The translational dynamics of molecules provide a signature for molecular size and shape size, the visco-elasticity of the surrounding fluid medium, their organization into supramolecular assemblies, their exchange between different sites, their intermittent binding, their confinement by a surrounding matrix or phase boundary, and the topology of that confinement. This book takes us through the various underlying principles of molecular translational dynamics, outlining the ways in which magnetic resonance, through the use of magnetic field gradients, can reveal those dynamics. It covers the full range of time and Frequency Domain methodologies, showing how they can be used, as well as advances in ‘scattering and diffraction’ methods, multidimensional exchange and correlation experiments, and orientational correlation methods ideal for studying dynamics in anisotropic environments.