Cathode Processes in the Mercury Arc

Although the electric arc is perhaps the oldest field in elec tronics, it is still one of the least well understood. The beautiful and complex phenomena accompanying the conduction of electricity in gases have led to the development of spectroscopy (and thus of atomic structure and quantum theory), discovery of isotopes, of the electron itself, of X-rays and thus to Moseley's discovery of atomic number, to the discovery of electron emission, and thus to modern electronic technology as well as to much of modern physics. The properties of the plasma state of matter, which until relatively recently could be produced only by the passage of electricity through a gas, have helped explain many natural phenomena ranging from lightning, the aurora, and the ionosphere to solar, stellar, and mushroom-cloud physics. Many plasma devices, such as neon signs, sodium and mercury lamps, thyratrons, ignitrons, and mer cury pool rectifiers, have been with us for decades, and more are still being invented. To name but a few recent ones, we have plasma torches, plasma propulsion devices for space flight, and magnetohydrodynamic generators. Solving the problem of contain ing a high -energy plasma would lead to controlled energy generation by nuclear fusion. Plasma physics is thus more vigorous than ever in spite of its venerable old age. Kesaev's book is concerned in its entirety with one of the least satisfactorily understood aspects of the relation of a plasma to the electrodes bounding and maintaining it.

Klappentext

Although the electric arc is perhaps the oldest field in elec­ tronics, it is still one of the least well understood. The beautiful and complex phenomena accompanying the conduction of electricity in gases have led to the development of spectroscopy (and thus of atomic structure and quantum theory), discovery of isotopes, of the electron itself, of X-rays and thus to Moseley's discovery of atomic number, to the discovery of electron emission, and thus to modern electronic technology as well as to much of modern physics. The properties of the plasma state of matter, which until relatively recently could be produced only by the passage of electricity through a gas, have helped explain many natural phenomena ranging from lightning, the aurora, and the ionosphere to solar, stellar, and mushroom-cloud physics. Many plasma devices, such as neon signs, sodium and mercury lamps, thyratrons, ignitrons, and mer­ cury pool rectifiers, have been with us for decades, and more are still being invented. To name but a few recent ones, we have plasma torches, plasma propulsion devices for space flight, and magnetohydrodynamic generators. Solving the problem of contain­ ing a high -energy plasma would lead to controlled energy generation by nuclear fusion. Plasma physics is thus more vigorous than ever in spite of its venerable old age. Kesaev's book is concerned in its entirety with one of the least satisfactorily understood aspects of the relation of a plasma to the electrodes bounding and maintaining it.

Inhalt

1. The Present State of Knowledge of the Cold Arc.- 1. General Description of the Arc Discharge.- A. Properties of the Cathode Spot on Mercury and Other Metals.- B. Development of Ideas on the Arc-Discharge Mechanism.- C. The Most Probable Mechanism for the Cold-Cathode Arc. Additional Methods of Investigation.- 2. The Stability of the Mercury Cathode Arc.- 21. Statement of the Problem.- A. Statistical Study of Spontaneous Arc Extinction.- B. Oscillational Process in the Cathode Region and the Restoring Mechanism of the Arc.- C. The Problem of Arc Stability and How It is Affected by Various Internal Factors.- 3. The Focal Structure and the Continuous Decay and Re-formation of the Cathode Spot on a Mercury Cathode.- 33. Fundamental Problems and Methods of Investigating the Cathode Spot.- A. Structure and Behavior of the Cathode Spot on Mercury Under Steady-State Current Conditions.- B. How an Arc Discharge is Set Up, and How It Changes from One Steady State to Another.- C. Re-formation of the Cathode Spot in the Steady State and the Role Played in the Process by a Magnetic Field.- 4. Basic Forms of Cathode-Spot Re-formation on a Homogeneous Liquid Cathode.- 46. Problems and Importance of Investigating the Motion of the Spot. Need to Include the Effect of the Inherent Magnetic Field of the Arc.- A. Regular Motion of the Cathode Spot on a Liquid Mercury Cathode.- B. Division of the Cathode Spot and Interaction Between Autonomous Spots.- C. Chaotic Motion of the Cathode Spot on a Homogeneous Liquid Cathode.- Conclusion.- Appendices.- 1. Method of Testing Mass-Produced Mercury Tubes.- 2. Magnetic Anchoring of the Cathode Spot and Protection of the Metal Shell of Mercury Tubes.- 3. Measuring the Amount of Mercury Atomized and Evaporated by the Cathode Spot and the Recoil Forces Experienced by the Cathode.- a. Determination of the Mercury Losses.- b. Weighing the Cathode Spot.- 4. Generation of Mercury Drops by the Cathode Spot.- Literature Cited.