Crookes Tube Schematic (hot cathode variation) The low voltage power supply (A) is connected to heat the cathode (C). The higher voltage power supply (B) energizes the phosphor-coated anode (P). The mask (M) is connected to the cathode potential and its image is seen on the phosphor as a non-glowing area. This tube may be built without supply A by using a cold cathode Image File history File links CrookesTube. ... Note: Principles are mostly the same for cold cathode ion sources as in particle accelerators to create electrons. ...

The Crookes tube is an evacuated glass cone with 3 node elements (one anode and two cathodes). It is an invention of the 19th century scientist William Crookes and is an evolutionary development of the earlier Geissler tube. Image File history File linksMetadata Download high resolution version (2288x1712, 494 KB) Summary An electron tube on display in the lobby of the Science Building at Winthrop University. ... Look up Vacuum in Wiktionary, the free dictionary. ... It has been suggested that Electrical component be merged into this article or section. ... Diagram of a zinc anode in a galvanic cell. ... Diagram of a copper cathode in a Daniells cell. ... Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ... Sir William Crookes, OM, FRS (17 June 1832 – 4 April 1919) was an English chemist and physicist. ... The Geissler tube is a glass tube for demonstrating the principles of electrical discharge. ...

Description of ultilization

The Crookes tube was designed to explore phosphorescent effects observed in the Geissler tubes — at high vacuum any phosphorescent material within the low pressure envelope would glow, but only at one terminal. The excitation of the phosphor was attributed by Crookes to what he called cathode rays, and which are now interpreted to not be rays but rather particles. These particles are electrons. The Geissler tube is a glass tube for demonstrating the principles of electrical discharge. ... Look up Vacuum in Wiktionary, the free dictionary. ... A schematic diagram of a Crookes tube apparatus. ... This article is about waves in the most general scientific sense. ... In particle physics, an elementary particle or fundamental particle is a particle not known to have substructure; that is, it is not made up of smaller particles. ... e- redirects here. ...

At the small end of a glass cone, an electrically heated wire, called the cathode, produces electrons. At the opposite end, a phosphor coated screen forming an anode is connected to the positive terminal of a voltage source of modest voltage (a few hundred volts), whose negative end is connected to the cathode. In between the cathode and the anode is placed a third element, a flat plate with some distinctive shape (the shadow mask), also connected to the cathode. When the appropriate voltages are applied to the various elements the screen will be seen to glow. A non-glowing image of the shadow mask will be imposed upon the screen. Glass can be made transparent and flat, or into other shapes and colors as shown in this sphere from the Verrerie of Brehat in Brittany. ... This article is about the geometric object, for other uses see Cone. ... Diagram of a copper cathode in a Daniells cell. ... A phosphor is a substance that can exhibit the phenomenon of fluorescence (glowing during absorption of radiation of another kind) or phosphorescence (sustained glowing without further stimulus). ... Diagram of a zinc anode in a galvanic cell. ... The shadow mask is one of two major technologies used to manufacture cathode ray tube (CRT) televisions and computer displays that produce color images (the other is aperture grille). ...

Improvements and innovations

Representation of an oscilloscope

Replacing the shadow mask with a beam focusing cylinder created the electron gun, which enabled the creation of a spot of illumination. The addition of electrostatic deflectors in the horizontal and vertical planes allowed the visualization of voltages applied to the deflectors. In this way, the tube was eventually developed as the display portion of the oscilloscope (a diagnostic and display device for use in electronics). This was further developed as a display device for radar and television displays using external magnetic coils for focusing and deflection. The principle of the shadow mask was exploited in displays for color television sets. Image File history File links Oscilloscope_diagram. ... Image File history File links Oscilloscope_diagram. ... Electron gun from a cathode ray tube An electron gun is a component that produces an electron stream that has a precise kinetic energy, being used in all TVs and monitors which use cathode ray tube technology, and in other instruments, eg. ... A Tektronix model 475A portable analogue oscilloscope, a very typical instrument of the late 1970s. ... This article is about the engineering discipline. ... This long range Radar antenna, known as ALTAIR, is used to detect and track space objects in conjunction with ABM testing at the Ronald Reagan Test Site on the Kwajalein atoll[1]. Radar is a system that uses radio waves to determine and map the location, direction, and/or speed... The shadow mask is one of two major technologies used to manufacture cathode ray tube (CRT) televisions and computer displays that produce color images (the other is aperture grille). ...

It was also observed that the application of high voltage (e.g. 25,000 volts) to the anode within a high vacuum tube would produce X-rays (observed by the inadvertent fogging of photographic film, even though it was within a light proof enclosure). Specialized tubes were developed that replaced the phosphor with a metal target and which focused the beam on a small spot to aid in obtaining a point source of the rays - this would then produce a sharp image of intervening material on the film. In electrical engineering High voltage refers to a voltage which is high. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... This article or section does not cite its references or sources. ...

External links

• an illustration of a "maltese cross" Crookes tube.
• The Cathode Ray Tube site
• Crookes and Geissler tubes shown working