In this volume I attempt to present concisely the physical principles underlying the operation and performance characteristics of the class of semiconductor p-n-p-n switches known as thyristors. The semiconductor controlled rectifier (SCR), the triode AC switch (Triac) the gate turn-off switch (GTO), and the reverse conducting thyristor (RCT) are some of the most important devices belonging to this device family. This book is aimed both at semiconductor-device physicists, designers, and students and at those electronic circuit designers who wish to apply thyristors creatively without the limitation of con­ sidering them as "black boxes," described only by insufficiently understood electrical ratings. The book endeavors to present an up-to-date account of the progress made in understanding the operation, potentialities, and limitations of thyristors as switching circuit elements. It assumes some basic knowledge of transistor physics and stresses the phe­ nomenological aspects of thyristor theory with the use of mathe­ matics not going beyond calculus and differential equations. The first two chapters discuss basic thyristor operation theory. The sub­ sequent chapters are devoted to the study of the static and dynamic properties of the SCR, the RCT, the GTO, and the triac; they in­ clude discussions of forward voltage drops, maximum voltage­ blocking capabilities, turn-on and turn-off transients, current and voltage rise rates, and desirable and undesirable triggering effects.

The motions of liquids in moving containers constitute a broad class of problems of great practical importance in many technical fields. The influence of the dynamics of the liquid on the motions of the container itself is a most interesting and complex aspect of the general subject, whether one considers only the rigid-body motions of the container or its elastic motions as well. It is most fitting therefore that this translation of Professor Rapoport's book has been undertaken so promptly following its original publication, so as to make readily available this rather detailed account of the mathematical foundations underlying the treatment of such prob­ lems. Since most of this vast body of analysis has been developed over the past decade by scientists in the USSR, and has therefore been largerly unavailable to those unable to read Russian, this volume will undoubtedly be of great value to many of us. H.

During the last decade, rapid growth of knowledge in the field of jet, rocket, nuclear, ion and electric propulsion has resulted in many advances useful to the student, engineer and scientist. The purpose for offering this course is to make available to them these recent advances in theory and design. Accordingly, this course is organized into seven parts: Part 1 Introduction; Part 2 Jet Propulsion; Part 3 Rocket Propulsion; Part 4 Nuclear Propulsion; Part 5 Electric and Ion Propulsion; Part 6 Theory on Combustion, Detonation and Fluid Injection; Part 7 Advanced Concepts and Mission Applications. It is written in such a way that it may easily be adopted by other universities as a textbook for a one semester senior or graduate course on the subject. In addition to the undersigned who served as the course instructor and wrote Chapter I, 2 and 3, guest lecturers included: DR. G. L. DUGGER who wrote Chapter 4 "Ram-jets and Air-Aug­ mented Rockets," DR. GEORGE P. SUTTON who wrote Chapter 5 "Rockets and Cooling Methods," DR . . MARTIN SUMMERFIELD who wrote Chapter 6 "Solid Propellant Rockets," DR. HOWARD S. SEIFERT who wrote Chapter 7 "Hybrid Rockets," DR. CHANDLER C. Ross who wrote Chapter 8 "Advanced Nuclear Rocket Design," MR. GEORGE H. McLAFFERTY who wrote Chapter 9 "Gaseous Nuclear Rockets," DR. S. G. FORBES who wrote Chapter 10 "Electric and Ion Propul­ sion," DR. R. H. BODEN who wrote Chapter 11 "Ion Propulsion," DR.

This book by Yeo V. Stupochenko, S. A. Losev and A. I. Osipov distin- guishes itself as an unusually comprehensive treatment of both the the- oretical and experimental aspects of the subject of relaxation processes in shock waves. S. A. Losev has done a considerable amount of work in molec- ular absorption spectroscopy of gases in relaxation, and, consequently, the chapter on experimental methods of study of nonequilibrium phenomena in shock waves has turned out to be particularly extensive in both scope and depth. A. I. Osipov has contributed extensively to the theoretical understanding of relaxation processes in gases through his work on transi- tion probability in nonadiabatic collisions by quantum-mechanical calcula- tion as can be seen from the many quotations in the chapter on relaxation processes in shock waves. Finally, Yeo V. Stupochenko's heavy contribution to the development of the study of nonequilibrium gas flow must also be mentioned, as it is obviously reflected at various places throughout the book.It is worth particular mention that the authors have compiled the most extensive bibliography of references (over six hundred in total) in the litera- ture of relaxation gasdynamics to date. The authors' thorough familiarity with the Western (particularly American) work in this ,!rea can be seen from the many Western reference"~quoted, about two-thirds of the total number. On the contrary, most of the more than two hundred Russian references are not popularly known in the West and, therefore, should be of value to the English-speaking readers.

During the last decade, a rapid growth of knowledge in the field of re-entry and planetary entry has resulted in many significant advances useful to the student, engineer and scientist. The purpose of offering this course is to make available to them these recent significant advances in physics and technology. Accordingly, this course is organized into five parts: Part 1, Entry Dynamics, Thermodynamics, Physics and Radiation; Part 2, Entry Abla­ tion and Heat Transfer; Part 3, Entry Experimentation; Part 4, Entry Concepts and Technology; and Part 5, Advanced Entry Programs. It is written in such a way so that it may easily be adopted by other universities as a textbook for a two semesters senior or graduate course on the sub­ ject. In addition to the undersigned who served as the course instructor and wrote Chapters, 1, 2, 3 and 4, guest lecturers included: Prof. FRANKLIN K. MOORE who wrote Chapter 5 "Entry Radiative Transfer," Prof. SHIH-I PAl who wrote Chapter 6 "Entry Radiation-Magnetogasdy­ namics," Dr. CARL GAZLEY, Jr. who wrote Chapter 7 "Entry Deaccelera­ tion and Mass Change of an Ablating Body," Dr. SINCLAIRE M. SCALA who wrote Chapter 8 "Entry Heat Transfer and Material Response," Mr.

During the last decade, a rapid growth of knowledge in the field of re-entry and planetary entry has resulted in many significant advances useful to the student, engineer and scientist. The purpose of offering this course is to make available to them these recent significant advances in physics and technology. Accordingly, this course is organized into five parts: Part 1, Entry Dynamics, Thermodynamics, Physics and Radiation; Part 2, Entry Abla­ tion and Heat Transfer; Part 3, Entry Experimentation; Part 4, Entry Concepts and Technology; and Part 5, Advanced Entry Programs. It is written in such a way so that it may easily be adopted by other universities as a textbook for a two semesters senior or graduate course on the sub­ ject. In addition to the undersigned who served as the course instructor and wrote Chapters, 1, 2, 3 and 4, guest lecturers included: Prof. FRANKLIN K. MOORE who wrote Chapter 5 "Entry Radiative Transfer," Prof. SHIH-I PAI who wrote Chapter 6 "Entry Radiation-Magnetogasdy­ namics," Dr. CARL GAZLEY, J r. who wrote Chapter 7 "Entry Deaccelera­ [ion and Mass Change of an Ablating Body," Dr. SINCLAIRE M. SCALA who wrote Chapter 8 "Entry Heat Transfer and Material Response," Mr.

The electric probe has long been used as a fundamental diagnostic tool for measuring the local properties of a plasma. Since Langmuir first developed the electric-probe technique in 1924, probes have been used to measure electron densities and temperatures in a wide variety of gaseous ionized media, such as electric discharges, afterglows, ionizing shock waves, flames, MHD, and plasma-jet flows, reentry vehicle flow fields, and atmospheric and space plasmas. The first systematic account of modern theories of electriC-probe behavior was given by Chen (1965), who also provided practical information on experimental techniques. A subsequent survey by Swift and Schwar (1970), which was representative of results contained in the literature through 1969, included additional information on some of the modern theories and on practical details of probe utilization. The purpose of this volume is to supplement the previously mentioned two works by providing an account of a large body of the up-to-date informa­ tion available on electric probes, particularly in the areas of transitional and continuum-flow phenomena, and by offering, for all domains of probe appli­ cation, a critical appraisal of the more significant probe theories and experi­ mental investigations in the literature.

On first acquaintance the electric arc discharge appears to be both visually attractive and a relatively simple phenomena to understand. To those of us engaged in prolonged study of this discharge, it remains a constantly exciting phenomena but we become only too aware of its complex nature and the difficulties in interpreting its bulk properties. This is particu­ larly true when the arc exists in a practical device and is subjected therefore to extreme conditions. In recent years the possibilities for the beginning of a fuller understanding of the complexities of the arc has arisen out of the excellent research and development work of scientists and engineers throughout the world. Much of this work has been stimulated not only by the need for the development of practical devices but also by the interest in thermonuclear fusion, mag­ netohydrodynamic generation and space exploration. In much of this work, the arc discharge has been a common feature as a source of study of high temperature plasma. As a result of this increased interest in the arc, the expert and would-be expert is now faced with the problem of assessing extensive newly published information on arc properties. Thus there is the need for texts which present to the engineer and researcher a review and summary of the present situation. This book is a valuable contribution to this task.

The dynamics of bodies containing fluids is a subject of long-standing im­ portance in many technical applications. The stability of motion of such bodies, in particular, has been the subject of study by Soviet engineers and applied mathematicians who have brought their fuH powers of analysis to bear on the problem, and have succeeded in developing a very weH-founded body of theory. It is difficult to find a more striking example anywhere of the application of the classical methods of analytical mechanics, together with more modern concepts of stability analysis, in such a comprehensive and elegent form as that presented by Profs. Moiseyev and Rumyantsev. Therefore, it is highly significant that this recent monograph has been trans­ lated and made available to the English-speaking community. H. NORMAN ABRAMSON San Antonio July, 1967 v Foreword During the last 15-20 years, problems of dynamics of rigid bodies with fluid-filled cavities have increasingly attracted the attention of scientists.

The book Foams: Theory and Industrial Applications, written by the undersigned and three collaborators and published in 1953, is still the only monograph on liquid foam in the English language. Naturally the science of foams had advanced in the intervening years so that a practically new book had to be prepared to give justice to the present state of our know­ ledge. This monograph has only one author and does not deal with solid foams, fire-fighting foams, and flotation, on which information is available elsewhere. The other applications of foam and its fundamental properties are reviewed at length and, whenever possible, attempts are made to reach the truth through a maze of conflicting evidence. February 1973 J. J. BIKERMAN Contents page Preface . v 1. General. Foam Films (Sections 1-22) 1 Foam Films 5 References 30 2. Formation and Structure (Sections 23-42) 33 Dispersion Methods 33 Condensation Methods 51 Foam Structure 59 References 62 3. Measurement of Foaminess (Sections 43-62) 65 Films and Bubbles 66 Foams. 76 References 94 4. Results of Foaminess Measurements (Sections 63-84) . 98 Poorly Foaming Liquids . 98 Strongly Foaming Liquids 108 Other Systems 132 References 140 5. Three-phase Foams (Sections 85-90) 149 References 157 6. Foam Drainage (Sections 91-106) 159 Experimental Data . 173 References 181 7. Mechanical Properties of Foams (Sections 107-122) 184 References 211 8. Optical Properties of Foams (Sections 123 -127) . 214 References 222 vii viii Contents 9.

Geometrical optics is no longer fashionable. Research workers do not expect significant new discoveries to be made in this field of classical physics. Teachers avoid the subject because its use for many generations in arid mathematical exercises has robbed it of all freshness and stimulus, with the result that it no longer seems relevant to a modern physics course. There remains - and perhaps this has grown in recent year- the technical significance of geometrical optics. It provides the basis for the design of optical instruments for use in everyday life as well as for scientific and industrial purposes. This small book is intended to treat two aspects of the subject: the laws of geometrical optics and their application to the design of optical instruments. The theory is not based on Snell's law of refraction but on a conservation law for the radiated energy. The subject can then be treated in a manner appropriate to contemporary physics: auxiliary geometrical parameters become unnecessary and the singularities resulting from their use vanish. The laws of geometrical optics can be formulated much more simply and their physical significance is revealed more clearly. I have tried to present the material in a form satisfactory both to teachers and to workers in the technical applications of optics. The content has thus been deliberately kept within the limits of a pocket book.

In this volume I attempt to present concisely the physical principles underlying the operation and performance characteristics of the class of semiconductor p-n-p-n switches known as thyristors. The semiconductor controlled rectifier (SCR), the triode AC switch (Triac) the gate turn-off switch (GTO), and the reverse conducting thyristor (RCT) are some of the most important devices belonging to this device family. This book is aimed both at semiconductor-device physicists, designers, and students and at those electronic circuit designers who wish to apply thyristors creatively without the limitation of con­ sidering them as "black boxes," described only by insufficiently understood electrical ratings. The book endeavors to present an up-to-date account of the progress made in understanding the operation, potentialities, and limitations of thyristors as switching circuit elements. It assumes some basic knowledge of transistor physics and stresses the phe­ nomenological aspects of thyristor theory with the use of mathe­ matics not going beyond calculus and differential equations. The first two chapters discuss basic thyristor operation theory. The sub­ sequent chapters are devoted to the study of the static and dynamic properties of the SCR, the RCT, the GTO, and the triac; they in­ clude discussions of forward voltage drops, maximum voltage­ blocking capabilities, turn-on and turn-off transients, current and voltage rise rates, and desirable and undesirable triggering effects.

The motions of liquids in moving containers constitute a broad class of problems of great practical importance in many technical fields. The influence of the dynamics of the liquid on the motions of the container itself is a most interesting and complex aspect of the general subject, whether one considers only the rigid-body motions of the container or its elastic motions as well. It is most fitting therefore that this translation of Professor Rapoport's book has been undertaken so promptly following its original publication, so as to make readily available this rather detailed account of the mathematical foundations underlying the treatment of such prob­ lems. Since most of this vast body of analysis has been developed over the past decade by scientists in the USSR, and has therefore been largerly unavailable to those unable to read Russian, this volume will undoubtedly be of great value to many of us. H.

During the last decade, rapid growth of knowledge in the field of jet, rocket, nuclear, ion and electric propulsion has resulted in many advances useful to the student, engineer and scientist. The purpose for offering this course is to make available to them these recent advances in theory and design. Accordingly, this course is organized into seven parts: Part 1 Introduction; Part 2 Jet Propulsion; Part 3 Rocket Propulsion; Part 4 Nuclear Propulsion; Part 5 Electric and Ion Propulsion; Part 6 Theory on Combustion, Detonation and Fluid Injection; Part 7 Advanced Concepts and Mission Applications. It is written in such a way that it may easily be adopted by other universities as a textbook for a one semester senior or graduate course on the subject. In addition to the undersigned who served as the course instructor and wrote Chapter I, 2 and 3, guest lecturers included: DR. G. L. DUGGER who wrote Chapter 4 "Ram-jets and Air-Aug­ mented Rockets," DR. GEORGE P. SUTTON who wrote Chapter 5 "Rockets and Cooling Methods," DR . . MARTIN SUMMERFIELD who wrote Chapter 6 "Solid Propellant Rockets," DR. HOWARD S. SEIFERT who wrote Chapter 7 "Hybrid Rockets," DR. CHANDLER C. Ross who wrote Chapter 8 "Advanced Nuclear Rocket Design," MR. GEORGE H. McLAFFERTY who wrote Chapter 9 "Gaseous Nuclear Rockets," DR. S. G. FORBES who wrote Chapter 10 "Electric and Ion Propul­ sion," DR. R. H. BODEN who wrote Chapter 11 "Ion Propulsion," DR.

This book by Yeo V. Stupochenko, S. A. Losev and A. I. Osipov distin- guishes itself as an unusually comprehensive treatment of both the the- oretical and experimental aspects of the subject of relaxation processes in shock waves. S. A. Losev has done a considerable amount of work in molec- ular absorption spectroscopy of gases in relaxation, and, consequently, the chapter on experimental methods of study of nonequilibrium phenomena in shock waves has turned out to be particularly extensive in both scope and depth. A. I. Osipov has contributed extensively to the theoretical understanding of relaxation processes in gases through his work on transi- tion probability in nonadiabatic collisions by quantum-mechanical calcula- tion as can be seen from the many quotations in the chapter on relaxation processes in shock waves. Finally, Yeo V. Stupochenko's heavy contribution to the development of the study of nonequilibrium gas flow must also be mentioned, as it is obviously reflected at various places throughout the book.It is worth particular mention that the authors have compiled the most extensive bibliography of references (over six hundred in total) in the litera- ture of relaxation gasdynamics to date. The authors' thorough familiarity with the Western (particularly American) work in this ,!rea can be seen from the many Western reference"~quoted, about two-thirds of the total number. On the contrary, most of the more than two hundred Russian references are not popularly known in the West and, therefore, should be of value to the English-speaking readers.

During the last decade, a rapid growth of knowledge in the field of re-entry and planetary entry has resulted in many significant advances useful to the student, engineer and scientist. The purpose of offering this course is to make available to them these recent significant advances in physics and technology. Accordingly, this course is organized into five parts: Part 1, Entry Dynamics, Thermodynamics, Physics and Radiation; Part 2, Entry Abla­ tion and Heat Transfer; Part 3, Entry Experimentation; Part 4, Entry Concepts and Technology; and Part 5, Advanced Entry Programs. It is written in such a way so that it may easily be adopted by other universities as a textbook for a two semesters senior or graduate course on the sub­ ject. In addition to the undersigned who served as the course instructor and wrote Chapters, 1, 2, 3 and 4, guest lecturers included: Prof. FRANKLIN K. MOORE who wrote Chapter 5 "Entry Radiative Transfer," Prof. SHIH-I PAl who wrote Chapter 6 "Entry Radiation-Magnetogasdy­ namics," Dr. CARL GAZLEY, Jr. who wrote Chapter 7 "Entry Deaccelera­ tion and Mass Change of an Ablating Body," Dr. SINCLAIRE M. SCALA who wrote Chapter 8 "Entry Heat Transfer and Material Response," Mr.

During the last decade, a rapid growth of knowledge in the field of re-entry and planetary entry has resulted in many significant advances useful to the student, engineer and scientist. The purpose of offering this course is to make available to them these recent significant advances in physics and technology. Accordingly, this course is organized into five parts: Part 1, Entry Dynamics, Thermodynamics, Physics and Radiation; Part 2, Entry Abla­ tion and Heat Transfer; Part 3, Entry Experimentation; Part 4, Entry Concepts and Technology; and Part 5, Advanced Entry Programs. It is written in such a way so that it may easily be adopted by other universities as a textbook for a two semesters senior or graduate course on the sub­ ject. In addition to the undersigned who served as the course instructor and wrote Chapters, 1, 2, 3 and 4, guest lecturers included: Prof. FRANKLIN K. MOORE who wrote Chapter 5 "Entry Radiative Transfer," Prof. SHIH-I PAI who wrote Chapter 6 "Entry Radiation-Magnetogasdy­ namics," Dr. CARL GAZLEY, J r. who wrote Chapter 7 "Entry Deaccelera­ [ion and Mass Change of an Ablating Body," Dr. SINCLAIRE M. SCALA who wrote Chapter 8 "Entry Heat Transfer and Material Response," Mr.

The electric probe has long been used as a fundamental diagnostic tool for measuring the local properties of a plasma. Since Langmuir first developed the electric-probe technique in 1924, probes have been used to measure electron densities and temperatures in a wide variety of gaseous ionized media, such as electric discharges, afterglows, ionizing shock waves, flames, MHD, and plasma-jet flows, reentry vehicle flow fields, and atmospheric and space plasmas. The first systematic account of modern theories of electriC-probe behavior was given by Chen (1965), who also provided practical information on experimental techniques. A subsequent survey by Swift and Schwar (1970), which was representative of results contained in the literature through 1969, included additional information on some of the modern theories and on practical details of probe utilization. The purpose of this volume is to supplement the previously mentioned two works by providing an account of a large body of the up-to-date informa­ tion available on electric probes, particularly in the areas of transitional and continuum-flow phenomena, and by offering, for all domains of probe appli­ cation, a critical appraisal of the more significant probe theories and experi­ mental investigations in the literature.

On first acquaintance the electric arc discharge appears to be both visually attractive and a relatively simple phenomena to understand. To those of us engaged in prolonged study of this discharge, it remains a constantly exciting phenomena but we become only too aware of its complex nature and the difficulties in interpreting its bulk properties. This is particu­ larly true when the arc exists in a practical device and is subjected therefore to extreme conditions. In recent years the possibilities for the beginning of a fuller understanding of the complexities of the arc has arisen out of the excellent research and development work of scientists and engineers throughout the world. Much of this work has been stimulated not only by the need for the development of practical devices but also by the interest in thermonuclear fusion, mag­ netohydrodynamic generation and space exploration. In much of this work, the arc discharge has been a common feature as a source of study of high temperature plasma. As a result of this increased interest in the arc, the expert and would-be expert is now faced with the problem of assessing extensive newly published information on arc properties. Thus there is the need for texts which present to the engineer and researcher a review and summary of the present situation. This book is a valuable contribution to this task.

The dynamics of bodies containing fluids is a subject of long-standing im­ portance in many technical applications. The stability of motion of such bodies, in particular, has been the subject of study by Soviet engineers and applied mathematicians who have brought their fuH powers of analysis to bear on the problem, and have succeeded in developing a very weH-founded body of theory. It is difficult to find a more striking example anywhere of the application of the classical methods of analytical mechanics, together with more modern concepts of stability analysis, in such a comprehensive and elegent form as that presented by Profs. Moiseyev and Rumyantsev. Therefore, it is highly significant that this recent monograph has been trans­ lated and made available to the English-speaking community. H. NORMAN ABRAMSON San Antonio July, 1967 v Foreword During the last 15-20 years, problems of dynamics of rigid bodies with fluid-filled cavities have increasingly attracted the attention of scientists.

The book Foams: Theory and Industrial Applications, written by the undersigned and three collaborators and published in 1953, is still the only monograph on liquid foam in the English language. Naturally the science of foams had advanced in the intervening years so that a practically new book had to be prepared to give justice to the present state of our know­ ledge. This monograph has only one author and does not deal with solid foams, fire-fighting foams, and flotation, on which information is available elsewhere. The other applications of foam and its fundamental properties are reviewed at length and, whenever possible, attempts are made to reach the truth through a maze of conflicting evidence. February 1973 J. J. BIKERMAN Contents page Preface . v 1. General. Foam Films (Sections 1-22) 1 Foam Films 5 References 30 2. Formation and Structure (Sections 23-42) 33 Dispersion Methods 33 Condensation Methods 51 Foam Structure 59 References 62 3. Measurement of Foaminess (Sections 43-62) 65 Films and Bubbles 66 Foams. 76 References 94 4. Results of Foaminess Measurements (Sections 63-84) . 98 Poorly Foaming Liquids . 98 Strongly Foaming Liquids 108 Other Systems 132 References 140 5. Three-phase Foams (Sections 85-90) 149 References 157 6. Foam Drainage (Sections 91-106) 159 Experimental Data . 173 References 181 7. Mechanical Properties of Foams (Sections 107-122) 184 References 211 8. Optical Properties of Foams (Sections 123 -127) . 214 References 222 vii viii Contents 9.

Geometrical optics is no longer fashionable. Research workers do not expect significant new discoveries to be made in this field of classical physics. Teachers avoid the subject because its use for many generations in arid mathematical exercises has robbed it of all freshness and stimulus, with the result that it no longer seems relevant to a modern physics course. There remains - and perhaps this has grown in recent year- the technical significance of geometrical optics. It provides the basis for the design of optical instruments for use in everyday life as well as for scientific and industrial purposes. This small book is intended to treat two aspects of the subject: the laws of geometrical optics and their application to the design of optical instruments. The theory is not based on Snell's law of refraction but on a conservation law for the radiated energy. The subject can then be treated in a manner appropriate to contemporary physics: auxiliary geometrical parameters become unnecessary and the singularities resulting from their use vanish. The laws of geometrical optics can be formulated much more simply and their physical significance is revealed more clearly. I have tried to present the material in a form satisfactory both to teachers and to workers in the technical applications of optics. The content has thus been deliberately kept within the limits of a pocket book.