Gerhard Schaefer – författare

Pulsed power technology, in the simplest of terms, usually concerns the storage of electrical energy over relatively long times and then its rapid release over a comparatively short period. However, if we leave the definition at that, we miss a multitude of aspects that are important in the ultimate application of pulsed power. It is, in fact, the application of pulsed power technology to which this series of texts will be focused. Pulsed power in today's broader sense means "special power" as opposed to the tra­ ditional situation of high voltage impulse issues related to the utility industry. Since the pulsed power field is primarily application driven, it has principally an engineering flavor. Today' s applications span those from materials processing, such as metal forming by pulsed magnetic fields, to other varied applications, such as psy­ chedelic strobe lights or radar modulators. Very high peak power applications occur in research for inertial confinement fusion, the Strategic Defense Initiative and other historical defense uses. lri fact it is from this latter direction that pulsed power has real­ ized explosive growth over the past half century. Early thrusts were in electrically powered systems that simulated the environment or effects of nuclear weapons detonation. More recently it is being utilized as prime power sources for directed energy weapons, such as lasers, microwaves, particle beam weapons, and even mass drivers (kinetic energy weapons).

The purpose of the 1989 NATO ARW was to develop applications, and an improved understanding of the physics for high current emission and conduction observed in hollow cathode-hollow anode switches including the pseudo spark and BLT. New applications include highly emissive cathodes for microwave devices, accelerators and free electron lasers, high power tubes, electron and ion beams, microlithography, accelerators, and other plasma devices. Recent research has produced a new generation of gas-phase plasma switches that are characterized by very high current emission and conduction while operating in a glow mode. These switches include the pseudospark and the BLT, both of which have hollow electrodes, switch over 10 to 100 kA peak current, and have cathodes with emission ~ 2 2 10,000 Ncm over ~ 1 cm area. The cathode properties are especially remarkable - about 2 orders of magnitude larger emission than existing thermionic cathodes. Part of the meeting was devoted to understanding these properties, and exploiting applications of this cathode. The remarkable properties of these switches are very surprising in the light of considerable previous work in this area, and these results deserve study in order to understand the underlying physical mechanisms, and to develop ideas and insight into future applications, and foster coherent research in this area. The operating cycle of pseudo-spark and BL T switches and related devices can be divided into four phases: hold-off, triggering, conduction, and recovery. There was very little discussion of the hold-off and recovery phases.

Pulsed power technology, in the simplest of terms, usually concerns the storage of electrical energy over relatively long times and then its rapid release over a comparatively short period. However, if we leave the definition at that, we miss a multitude of aspects that are important in the ultimate application of pulsed power. It is, in fact, the application of pulsed power technology to which this series of texts will be focused. Pulsed power in today's broader sense means "special power" as opposed to the tra­ ditional situation of high voltage impulse issues related to the utility industry. Since the pulsed power field is primarily application driven, it has principally an engineering flavor. Today' s applications span those from materials processing, such as metal forming by pulsed magnetic fields, to other varied applications, such as psy­ chedelic strobe lights or radar modulators. Very high peak power applications occur in research for inertial confinement fusion, the Strategic Defense Initiative and other historical defense uses. lri fact it is from this latter direction that pulsed power has real­ ized explosive growth over the past half century. Early thrusts were in electrically powered systems that simulated the environment or effects of nuclear weapons detonation. More recently it is being utilized as prime power sources for directed energy weapons, such as lasers, microwaves, particle beam weapons, and even mass drivers (kinetic energy weapons).

This text, a summary of Friedrich Christoph Oetinger's theosophical system, was first published in 1776, and is presented here in an historico-critical edition. As a peculiarly original exegete of scripture and with profound knowledge both of kabbalistic traditions and Jakob Bohme, Oetinger views a new stage of development of humanity as being on the way to the fulfilment of creation. Within the horizon of his century's enlightenment, he combines piety with the optimism of progress.

Gerthsen Physik will auch in Zukunft Studierenden wie Profis der Natur- und Ingenieurwissenschaften als umfassendes Lern-, Lehr- und Nachschlagewerk dienen. Um diesem Anspruch gerecht zu werden, haben zehn Autoren als Kenner ihrer Arbeitsgebiete für eine Rundumerneuerung gesorgt, die den Bogen von den elementaren Kenntnissen bis hin zu zeitgenössischer Forschung spannt – im „Gerthsen-Stil“ und alles in einem Buch!Unsere Darstellung legt großen Wert darauf, physikalische Phänomene und deren Interpretation ins Zentrum zu stellen:Der Gerthsen stellt die ganze Physik bewusst in nur einem Buch dar, indem er sich auf die zentralen Themen konzentriert. Vertiefungen machen auf wichtige weiterführende und herausfordernde Themen aufmerksam.Explizite Darstellungen von Schlüsselexperimenten zeigen, woher wir unsere Kenntnis über physikalische Phänomene beziehen.Die Mathematik, ohne Zweifel die Sprache der Physik, wird in Skizzen so weit vorgestellt, dass der Ursprung auch anspruchsvoller Modelle physikalischer Phänomene nachvollzogen werden kann.Am Ende jeden Kapitels sind die wichtigsten physikalischen Konzepte kurz zusammengefasst.Ausgewählte Übungsaufgaben vermitteln einen Eindruck davon, welche Fragestellungen konzeptioneller oder angewandter Art mit den Inhalten des jeweiligen Kapitels behandelt werden können.Der Gerthsen rekapituliert zur Hälfte die klassische Physik – Mechanik, Wärmelehre und Elektrodynamik – aus heutiger Sicht. Er schließt mit dem Kapitel über Relativitätstheorie und vergisst nicht, die Gravitationswellen zu behandeln, das erst zehn Jahre alte neue Beobachtungsfenster in die Physik dynamischer gekrümmter Raumzeiten. Die andere Hälfte führt tief hinein in die mikroskopische Physik: zunächst die Welt der Quanten, Atome, Moleküle, des Lichtes und der Festkörper. Sie beschließt die Reise durch die Physik mit dem Kapitel über Teilchenphysik – dem, was die Welt im physikalischen Innersten zusammenhält.