Electric fieldPhysical field surrounding an electric chargeAn electric field (sometimes called E-field) is a physical field that surrounds electrically charged particles such as electrons. In classical electromagnetism, the electric field of a single charge (or group of charges) describes their capacity to exert attractive or repulsive forces on another charged object.
ElectronThe electron (e, or β in nuclear reactions) is a subatomic particle whose electric charge is negative one elementary charge. It is an elementary particle contained in the matter that makes up the universe. All atoms are composed of electrons, as well as varying numbers protons and neutrons, but the electrons have almost 2,000 times less mass than the other two constituents.
Eugen GoldsteinEugen Goldstein (; German:; 5 September 1850 – 25 December 1930) was a German physicist. He was an early investigator of discharge tubes, and the discoverer of anode rays or canal rays, later identified as positive ions in the gas phase including the hydrogen ion. LifeGoldstein was born in 1850 in Gleiwitz (now known as Gliwice) to a Jewish family. He studied in Breslau and later in Berlin, under Helmholtz.
William CrookesSir William Crookes (; 17 June 1832 – 4 April 1919) was an English chemist and physicist who attended the Royal College of Chemistry, now part of Imperial College London, and worked on spectroscopy. He was a pioneer of vacuum tubes, inventing the Crookes tube, which was made in 1875. Observing cathode rays generated in these tubes, Crookes posited that "radiant matter" was a unique fourth state of matter, a foundational contribution to plasma physics.
Vacuum tubeDevice that controls current between electrodesLater thermionic vacuum tubes, mostly miniature style, some with top cap connections for higher voltagesA vacuum tube, vac tube, electron tube, thermionicvalve (British usage), or tube (North America) is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied.
Cathode ray tubeVacuum tube used to display imagesCathode ray tube cross section diagram (not to scale) with its focused and deflected electron beam (in green)Oscilloscope cathode ray tubeCutaway rendering of a color CRT:Electron guns (cathodes) for red, green, and blueElectron beamsFocusing coilsDeflection coilsAnode connectionShadow mask for separating beams for red, green, and blue parts of the displayed imagePhosphor layerClose-up of the phosphor layer showing red, green, and blue zonesCutaway rendering of a monochrome CRT:Deflection coilsElectron beamFocusing coilPhosphor layerFilament for heating the cathodeGraphite layer on the inner side of the tubeAnode connectionElectron gun (cathode)Air-tight glass body of the tubeScreenDeflection yokeControl electrode modulating the intensity of the electron beamContact pins for cathode, filament and control electrodeWire for anode high voltageThe only visible differences are the single electron gun, the uniform white phosphor coating, and the lack of a shadow mask.A Macintosh computer from the 1990s with integrated CRT displayA cathode ray tube (CRT) is a vacuum tube containing one or more electron guns, which emit electron beams, which are directed and controlled to display images on a phosphorescent screen.
Johann Wilhelm HittorfJohann Wilhelm Hittorf (27 March 1824 – 28 November 1914) was a German physicist who was born in Bonn and died in Münster, Germany. Hittorf was the first to compute the electricity-carrying capacity of charged atoms and molecules (ions), an important factor for understanding electrochemical reactions. He formulated ion transport numbers and the first method for their measurements. He experimented with tubes containing energy rays extending from a negative electrode.
CathodeA cathode is the electrode from which a conventional current leaves a polarized electrical device such as a lead–acid battery. This definition can be recalled by using the mnemonicCCD for cathode current departs. Conventional current describes the direction in which positive charges move.
J. J. ThomsonSir Joseph John Thomson (18 December 1856 – 30 August 1940) was a British physicist. He received the 1906 Nobel Prize in Physics "in recognition of the great merits of his theoretical and experimental investigations on the conduction of electricity by gases."
Julius PlückerJulius Plücker (16 July 1801 – 22 May 1868) was a German mathematician and physicist. He made fundamental contributions to the field of analytical geometry and was a pioneer in the investigations of cathode rays that led eventually to the discovery of the electron. He also vastly extended the study of Lamé curves. BiographyEarly yearsPlücker was born at Elberfeld (now part of Wuppertal) on July 16th, 1801.
VoltageVoltage, also known as (electrical) potential difference, electric pressure, or electric tension, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to move a positive test charge from the first point to the second point. In the International System of Units (SI), the derived unit for voltage is the volt (V).
ElectrodeAn electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor, an electrolyte, a vacuum or a gas). In electrochemical cells, electrodes are essential parts that can consist of a variety of materials (chemicals) depending on the type of cell. An electrode may be called either a cathode or anode according to the direction of the electric current, unrelated to the potential difference between electrodes.*As an Amazon Associate I earn from qualifying purchases.