Electron tubes

Because of it has great affinity for oxygen, the metal is used as a "getter" in electron tubes. It is also used in photoelectric cells, as well as a catalyst in the hydrogenation of certain organic compounds. 

Electron tubes Electron tunneling Electrooptic materials Electrooptics Electroosmosis... 

Titanium hydride is used as a source for Ti powder, alloys, and coatings as a getter in vacuum systems and electronic tubes as a sealer of metals and as a hydrogen source. 

The thermal expansivity of Ni—Fe alloys vary from ca 0 at ca 36 wt % Ni (Invar [12683-18-OJ) to ca 13 x 10 / C for Ni. Hence, a number of compositions, which are available commercially, match the thermal expansivities of glasses and ceramics for sealing electron tubes, lamps, and bushings. In addition, the thermal expansion characteristic is utilized ia temperature controls, thermostats, measuriag iastmments, and condensers. 

Incandescent Lamps, Electronic Tubes, and Resistance Elements. Articles fashioned in any form from molybdenum and tungsten usually fall within the bounds of powder metallurgy. These metals normally are first produced as a powder. Both molybdenum and tungsten are used as targets in x-ray tubes, for stmctural shapes such as lead and grid wires in electron tubes, and as resistance elements in furnaces. 

The addition of thoria to a Re—W ahoy produces a material having 74 wt % W, 24 wt % Re, and 2% Th02 that is used for heated cathodes in electron tubes. This material has good ducthity and high resistance to breaking by mechanical shock. 

Rhenium exhibits a greater resistance than tungsten to the water cycle effect, in which lamps and electron tubes become blackened by deposition of metal. This phenomenon involves catalysis by small quantities of water that react with the metal in a hot filament to produce a volatile metal oxide and hydrogen. The oxide condenses on the surface of the bulb and is reduced back to the metal by hydrogen. 

Bell Telephone Laboratories first demonstrates the transistor, a non-vacuum device that will eventually replace the conventional electron tubes. 

E. M. Boone, Circuit Theory of Electron Devues, John Wiley and Sons, New York, 1953. W. G. Dow, Fundamentals of Engineering Electronics, John Wiley and Sons, New York, second edition, 1952. J. Millman and S. Seely, Electronics, McGraw-Hill Book Co., New York, second edition, 1951. S. Seely, Electron-Tube Circuits, McGraw-IIill Book Co., second edition, New York, 1958. R. R. Wright. Electronics. Principles and Apjlications, The Ronald Press Co., New York, 1950. 

In its applications, science was encountering gradually-increasing difficulties in view of the impossibility of explaining numerous oscillatory phenomena, particularly those connected with the so-called self-sustained oscillations (first, the oscillating arcs and gaseous discharges and still later, the electron tube oscillators). 

The deep philosophical significance of the new theory lies precisely at this point, and consists in replacing a somewhat metaphysical concept of the harmonic oscillator (which could never be produced experimentally) by the new concept of a physical oscillator of the limit cycle type, with which we are dealing in the form of electron tube circuits and similar self-excited systems. 

A difference between these two concepts can be illustrated in many ways. Consider, for example, a mathematical pendulum in this case the old concept of trajectories around a center holds. On the other hand, in the case of a wound clock at standstill, clearly it is immaterial whether the starting impulse is small or large (as long as it is sufficient for starting, the ultimate motion will be exactly the same). Electron tube circuits and other self-excited devices exhibit similar features their ultimate motion depends on the differential equation itself and not on the initial conditions. 

The differential equation of an electron tube circuit with inductive coupling is ... 

In the nonlinear systems, one often encounters subharmonics that have frequencies lower than that of the fundamental wave. As an example, consider a nonlinear conductor of electricity such as an electron tube circuit in which there exists between the anode current ia and the grid voltage v, a relation of the form... 

Electron polarization operators, 539 Electron tube circuit, 373 Elias, P., 220 Elimination, Gaussian, 62 Elliot, N., 757 EUiot, R. J., 745 Energy operator, total, 541 Ensemble average, 2... 

Uses. Inert gas shield in arc welding air ships in mixtures with neon and argon for electronic tubes and neon signs... 

The most important use of barium is as a scavenger in electronic tubes. The metal, often in powder form or as an alloy with aluminum, is employed to remove the last traces of gases from vacuum and television picture tubes. Alloys of barium have numerous applications. It is incorporated to lead alloy grids of acid batteries for better performance and added to molten steel and metals in deoxidizing alloys to lower the oxygen content. Thin films of barium are used as lubricant suitable at high temperatures on the rotors of anodes in vacuum X-ray tubes and on alloys used for spark plugs. A few radioactive isotopes of this element find applications in nuclear reactions and spectrometry. 

Cesium is used as a getter in electron tubes. Other applications are in photoelectric cells ion propulsion systems heat transfer fluid in power generators and atomic clocks. The radioactive Cs-37 has prospective applications in sterilization of wheat, flour, and potatoes. 

Further, there are dry processes in w/hich degassing in vacuum is the actual technical process. These include work in induction- and arc furnaces, steel degassing plants, and plants for the manufacture of pure metals and electron tubes. 

Therefore, in UFIV (p < 10 mbar) the monolayer formation time is of the order of minutes to hours or longer and thus of the same length of time as that needed for experiments and processes in vacuum. The practical requirements that arise have become particularly significant in solid-state physics, such as for the study of thin films or electron tube technology. A UFIV system is different from the usual high vacuum system for the following reasons ... 

See also refs under Electron Microscope and under Electron Tube)... 

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