Type Of Cathode-ray Tube Research Articles

An extensive study on the neutron-gamma shielding and mass stopping power of (70-x) CRT–30K2O–xBaO glass system for 252Cf neutron source

ABSTRACT The present study focuses on the charged-uncharged particles shielding performance of the addition of a mixed type of cathode ray tube (CRT) in a glass system that is irradiated by the 252Cf neutron source via the MCNPX simulation and analytical calculations, as well as Phy-X: PSD and SRIM software. The CRT waste glass is inserted into the glass system with (70-x) CRT–30K2O–xBaO general formula for x = 0, 10, 20 mol% that produces CG1, CG2, and CG3 glass shielding materials. Using Watt Fission Distribution (WFD) and Doppler Effect (DE) the neutron-gamma photon spectra were extracted for shielded (in the presence of the glass materials) and unshielded (in air) cases. Some calculated attenuation parameters related to the neutron deduced that CG1 is the best neutron attenuator among the selected glass samples. Moreover, by increasing the density of the glass from CG1 to CG3, the ascending trend is observed for the linear attenuation coefficient (LAC, cm−1) of the studied glass, and the best shielding competence is monitored for CG3. Furthermore, two sharp peaks are found in Zeff graphs which may be due to K-edge absorption of Ba and Pb elements and by decreasing the Pb element from CG1 to CG3 the second peak gradually becomes smooth. In addition, Mass Stopping Power/ Projected Ranges of the proton (H1) and alpha particles (He+2) are also estimated by SRIM code and findings show that CG1 can better stop proton and alpha particles in comparison with the other chosen glass structures.

Röntgens merkwürdige Bestellung – ein Beitrag zur Entdeckungsgeschichte der Röntgenstrahlen

Due to the fact that Röntgen never reported the details of the discovery of his "new rays", he left the door open for speculative interpretations. As a contribution to a serious analysis of the history of Röntgen's discovery, this paper presents a previously unnoticed letter relating to an order of a number of very thin crystalline absorbers. The addressee is unfortunately unknown. The letter is dated November 15, 1895. Therefore, this letter must be considered to be the first well documented remark made by Röntgen after seeing the earliest indications of the new rays only one week earlier. The order seems to emphasize the role of a particular type of cathode ray tube developed by Philipp Lenard, Nobel Prize winner of 1905, and manufactured by the glassblower Louis Müller-Unkel in the discovery of the new radiation. It partly contradicts an analysis based on Röntgen's order book from Würzburg made by the author et al. some years ago. Completed by the document presented here, Röntgen's order correspondence allows some insight into Röntgen's intentions during this productive period. The autograph was found at Staatsbibliothek Berlin, Sammlung Darmstaedter, by the author.

Selbstdarstellung und Legendenbildung um das Müller-Unkelsche Lenard-Rohr

Ph. Lenard—the well known Nobel prize winner—felt to be deceived concerning the discovery of the X-rays by a ungrateful and jewish dominated fate. He complained over an insufficient appreciation of his precursory research work by the definitive discoverer W. C. Rontgen. Lenard proved this interpretation by his contributions to the development of a paticular type of cathode ray tube manufactured by the glass-blower L. Muller-Unkel and the decisive part this tube played in the discovery of the new radiation. This interpretation has been emphasized during the Third Reich and even nowaday it became not completely obliterate. Relying on recently discovered historical documents we describe the history of the origin of the Muller-Unkel tube. In this way we can demonstrate that essential parts of the interpretation of Ph. Lenard and his politically like-minded friends are to be transposed into the grounds of legends.

A new type of cathode-ray tube with a crossed-field gun

This paper introduces a new type of cathode-ray tube with a crossed-field electron gun which produces an electron beam in a region where a nonuniform magnetic field and an electric field cross perpendicularly. The new configuration gives increased freedom in the design of crossed-field guns. As a result, a long, directly heated cathode can be readily applied to a gun structure which makes high perveance and instant operation possible with much improved cathode heating efficiency. The new gun provides ion trap action by virtue of a magnetic field which separates ions from electrons due to the difference in their masses. A new type of cathode-ray tube using this gun not only demonstrates these features but also requires relatively low operational voltages for beam acceleration and control electrodes. The paper includes an analysis of electron motion in a crossed field with a nonuniform magnetic field. It also shows practical configuration of electrodes and current characteristics of the gun.

A new type of cathode-ray tube with a crossed-field gun

A new type of cathode-ray tube with a crossed-field gun

A decoder-driver system for magnetic-core memories using a 64-position switch tube

This paper describes the design, construction, and operation of a driver-decoder subsystem using a novel 64-position switch tube. The system is designed as part of a 10 Mc/s magnetic-core memory. The switch tube is a type of cathode-ray tube (CRT) using as a target, a 64-position matrix of silicon diodes. A split-plate electrostatic deflection system is used to select one diode out of the matrix, and turn it on with the electron beam. The effect of the beam is to produce a 1.5 ampere, 150 volt, 3 ns rise time pulse. The delay through the system is 25 ns.

Direct-view three-dimensional display tube

The three-dimensional display tube is a novel type of cathode-ray tube that directly displays volumetric analog information. In contrast to other presentations in which the third dimension is simulated stereoscopically or with color, this device displays the information in actual space. The three-dimensional display tube utilizes a phosphor coated disc spinning at 900 rpm within an evacuated sphere. Upon excitation by a cathode-ray beam at selected times, any point in the volume swept out by the rotating disc may be illuminated at 30 cps. The result is true volumetric analog display, which is visible without any special viewing position or glasses. Thus, minimum observer fatigue and equal display resolution in depth are possible as compared with existing stereoscopic three-dimensional displays. Different color phosphors on either side of the disc and appropriate cathode-ray beam gating provide a simple means of two color display. Also, special deflection scans that are compatible with particular display requirements can result in a display equal in brightness and quality to commercial television display. Some typical applications as well as the technical aspects of this type of display such as brightness, data storage requirements, and feed circuit bandwidths are discussed. Compatibility with normal observer vision and ease of determining target intersections within the display volume are important properties of this type of display.

A Thin Cathode-Ray Tube

A new type of cathode-ray tube typically only a few inches thick is described. The beam is injected parallel to one edge of the thin tube and caused to pass through two right-angle deflections: the first sends the beam into the region between the front and back tube surfaces, and the second turns it into the phosphor-coated front surface. A brief analysis of the deflection-focusing action is presented and the sweep-voltage requirements are described. The thin tube can be adapted to multicolor operation or to any other use to which cathode-ray tubes are put; it also has many unique features (in addition to small size), such as the capability of being viewed from both sides of the display screen or being rendered transparent.

The monoscope

The paper describes the basic principles of operation of the monoscope, a type of cathode-ray tube used to generate a stationary television picture. Some considerations in the design of the tube are discussed, together with suitable materials and methods for the preparation of the picture plates.

The life testing of cathode-ray tubes

The principal requirement of cathode-ray-tube life-testing equipment is that it shall give an accurate description of the life performance of any type of cathode-ray tube in the shortest possible time. This object is achieved only after due consideration of all the factors involved, which include the safety of personnel from electric shock and mechanical implosion, the flexibility and reliability of apparatus and methods of arriving at an estimate of life before failure actually occurs. The paper describes how the problem has been approached and concludes that the desired flexibility in the apparatus can best be achieved in an open-bench type of equipment. This entails the provision of electrical safeguards to protect the operator.

The use of the high-vacuum cathode-ray tube for recording high-speed transient phenomena

The paper describes a portable apparatus operated from the 50-cycle a.c. mains and devised for the visual examination and/or photographic recording of controlled or uncontrolled high-speed transient phenomena.A high-vacuum glass-bulb type of cathode-ray tube is employed, with external photography. The maximum working voltage is 5000 volts, and the beam is normally shut off by means of a negative voltage on the modulating grid. A 3-electrode spark-gap is incorporated and is so arranged that when broken down by an incoming transient, or artificiallyapplied impulse, it brings the cathode-ray spot to full brilliance almost instantaneously for a controllable length of time, and, at the same time, sweeps it across the screen at a speed which can be varied from 1 or 2 microseconds to 1 millisecond for a single horizontal sweep. A simple oscillatory circuit operated by the spark-gap is arranged to provide a time-marking wave when desired.

Use of a Radial Deflection Cathode Ray Oscillograph as a Time Comparator

THE comparator principle is well known in the accurate determination of lengths. It may also be applied to the measurement of time intervals. By installing an extra electrode system in a standard type of cathode ray tube, radial deflections and spiral time bases are readily produced. Such a modified tube has advantages over the ordinary tube when the latter is used to obtain radial deflections, whether by anode voltage modulation 1,2,3,4, or by auxiliary apparatus5.

A Velocity-Modulation Television System

MANY of the investigators who are seeking at the present time to develop a practical system of television make use of the cathode ray oscillograph tube in one form or another, since the electron beam in such a tube provides an easily controlled means of scanning the picture to be transmitted. At the receiving end, the cathode ray tube is employed to build-up the received picture by varying the intensity of the beam in accordance with the light and dark portions of the picture. The ordinary type of cathode ray tube, however, gives only a small range of intensity control without the accompaniment of loss of focus of the spot on the fluorescent screen, and special electrode systems have to be arranged to obtain good intensity modulation in this manner. As an alternative to this method, the intensity of the cathode ray beam may be kept constant but its tranverse velocity may be varied as it moves over the picture, the beam being speeded up over the dark portions of the picture and slowed down over the fight portions. The corresponding motion of the cathode ray beam at the receiving end thus gives varying illumination according to the speed of travel of the spot on the fluorescent screen, and with the aid of the phenomenon of persistence of vision, a true impression of the shades and contrasts in the picture received is obtained.

On the luminescence of solid nitrogen under cathode ray bombardment

After the discovery by Vegard of the luminescence which occured in solid nitrogen under cathode ray bombardment at the temperature of liquid hydrogen considerable interest was attached to it on account of his attempt to explain the well-known auroral green line as due to this luminescence under certain conditions in the upper atmosphere. His theory of the auroral line was not corroborated by the experiments of McLennan and others, who showed that the line was due to oxygen. But the luminescence in solid nitrogen retained a very considerable interest as an outstanding example of the phenomenon of luminescence. From this point of view its spectrum and its properties were further studied in this laboratory where there were available all the necessary facilities for low temperature research. The investigation was commenced by McLennan, Ireton and Thomson, and the present research was a continuation of their work. Its object was to photograph the spectrum more completely, and to obtain further data in connection with the luminescence which might lead to an adequate explanation of the phenomena observed. Apparatus for Producing the Luminescence . The apparatus for producing the luminescence was with some few improvements in detail, the same as that described by McLennan, Ireton and Thomson. Use was made of a type of cathode ray tube designed by Dr. Coolidge, of the General Electric Company. With such a tube it was possible to obtain high velocity cathode rays outside the generating tube. The essential details of the apparatus are shown in fig. 1.