Misplaced Pages

#947052

140-510: A Farnsworth–Hirsch fusor is the most common type of fusor. This design came from work by Philo T. Farnsworth in 1964 and Robert L. Hirsch in 1967. A variant type of fusor had been proposed previously by William Elmore, James L. Tuck , and Ken Watson at the Los Alamos National Laboratory though they never built the machine. Fusors have been built by various institutions. These include academic institutions such as

280-530: A Maxwellian cloud. This became the Lawson criterion . Fusors typically suffer from conduction losses due to the wire cage being in the path of the recirculating plasma. In the original fusor design, several small particle accelerators , essentially TV tubes with the ends removed, inject ions at a relatively low voltage into a vacuum chamber. In the Hirsch version of the fusor, the ions are produced by ionizing

420-410: A high-frequency magnetic field . The charge would then accumulate in the center of the tube, leading to high amplification. Unfortunately it also led to high erosion on the electrodes when the electrons eventually hit them, and today the multipactor effect is generally considered a problem to be avoided. What particularly interested Farnsworth about the device was its ability to focus electrons at

560-632: A pulp-magazine contest for inventing a magnetized car lock. Farnsworth was a member of the Church of Jesus Christ of Latter-day Saints . Farnsworth excelled in chemistry and physics at Rigby High School . He asked science teacher Justin Tolman for advice about an electronic television system that he was contemplating; he provided the teacher with sketches and diagrams covering several blackboards to show how it might be accomplished electronically, and Tolman encouraged him to develop his ideas. One of

700-496: A submarine ). In the case of classical electrodynamics , the differential equation is again the wave equation, and the scattering of light or radio waves is studied. In particle physics , the equations are those of Quantum electrodynamics , Quantum chromodynamics and the Standard Model , the solutions of which correspond to fundamental particles . In regular quantum mechanics , which includes quantum chemistry ,

840-486: A Scottish inventor who had given the world's first public demonstration of a working television system in London in 1926, using an electro-mechanical imaging system, and who was seeking to develop electronic television receivers. Baird demonstrated his mechanical system for Farnsworth. In May 1933, Philco severed its relationship with Farnsworth because, said Everson, "it [had] become apparent that Philo's aim at establishing

980-666: A broad patent structure through research [was] not identical with the production program of Philco." In Everson's view the decision was mutual and amicable. Farnsworth set up shop at 127 East Mermaid Lane in Philadelphia, and in 1934 held the first public exhibition of his device at the Franklin Institute in that city. After sailing to Europe in 1934, Farnsworth secured an agreement with Goerz-Bosch-Fernseh in Germany. Some image dissector cameras were used to broadcast

1120-405: A burned-out electric motor among some items discarded by the previous tenants and rewound the armature ; he converted his mother's hand-powered washing machine into an electric-powered one. He developed an early interest in electronics after his first telephone conversation with a distant relative, and he discovered a large cache of technology magazines in the attic of their new home. He won $ 25 in

1260-445: A coherent wave scatter from different centers. In certain rare circumstances, multiple scattering may only involve a small number of interactions such that the randomness is not completely averaged out. These systems are considered to be some of the most difficult to model accurately. The description of scattering and the distinction between single and multiple scattering are tightly related to wave–particle duality . Scattering theory

1400-401: A decision that proved crucial in later disputes with RCA. Most television systems in use at the time used image scanning devices (" rasterizers ") employing rotating " Nipkow disks " comprising a spinning disk with holes arranged in spiral patterns such that they swept across an image in a succession of short arcs while focusing the light they captured on photosensitive elements, thus producing

1540-401: A dilute gas in the chamber. In either version there are two concentric spherical electrodes , the inner one being charged negatively with respect to the outer one (to about 80 kV). Once the ions enter the region between the electrodes, they are accelerated towards the center. In the fusor, the ions are accelerated to several keV by the electrodes, so heating as such is not necessary (as long as

SECTION 10

#1732787256948

1680-706: A fatherless family could be excused from military service to provide for his family. He returned to Provo and enrolled at Brigham Young University , but he was not allowed by the faculty to attend their advanced science classes based upon policy considerations. He attended anyway and made use of the university's research labs, and he earned a Junior Radio-Trician certification from the National Radio Institute , and full certification in 1925. While attending college, he met Provo High School student Elma "Pem" Gardner (1908–2006), whom he eventually married. Farnsworth worked while his sister Agnes took charge of

1820-407: A few minutes before undergoing a fusion reaction, so that the monoenergetic picture of the fusor, at least for power production, is not appropriate. One consequence of the thermalization is that some of the ions will gain enough energy to leave the potential well, taking their energy with them, without having undergone a fusion reaction. There are a number of unsolved challenges with the electrodes in

1960-591: A field. In the course of a patent interference suit brought by the Radio Corporation of America in 1934 and decided in February 1935, his high school chemistry teacher, Justin Tolman, produced a sketch he had made of a blackboard drawing Farnsworth had shown him in spring 1922. Farnsworth won the suit; RCA appealed the decision in 1936 and lost. Farnsworth received royalties from RCA, but he never became wealthy. The video camera tube that evolved from

2100-596: A functioning transmitter tube before 1931. Farnsworth had lost two interference claims to Zworykin in 1928, but this time he prevailed and the U.S. Patent Office rendered a decision in 1934 awarding priority of the invention of the image dissector to Farnsworth. RCA lost a subsequent appeal, but litigation over a variety of issues continued for several years before Sarnoff finally agreed to pay Farnsworth royalties . In 1932, while in England to raise money for his legal battles with RCA, Farnsworth met with John Logie Baird ,

2240-448: A fusor power system. To begin with, the electrodes cannot influence the potential within themselves, so it would seem at first glance that the fusion plasma would be in more or less direct contact with the inner electrode, resulting in contamination of the plasma and destruction of the electrode. However, the majority of the fusion tends to occur in microchannels formed in areas of minimum electric potential, seen as visible "rays" penetrating

2380-419: A fusor-like device has been 3 × 10 neutrons per second with the deuterium-deuterium fusion reaction. Commercial startups have used the neutron fluxes generated by fusors to generate Mo-99 , a precursor to Technetium-99m , an isotope used for medical care. Philo T. Farnsworth Philo Taylor Farnsworth (August 19, 1906 – March 11, 1971) was an American inventor and television pioneer. He made

2520-434: A fusor. First, there is the high-voltage involved. Second, there are the x-ray and neutron emissions that are possible. Also there are the publicity / misinformation considerations with local and regulatory authorities. The fusor has been demonstrated as a viable neutron source . Typical fusors cannot reach fluxes as high as nuclear reactor or particle accelerator sources, but are sufficient for many uses. Importantly,

2660-402: A hot plasma cloud can be found with the following equation. where This equation shows that energy varies with the temperature, density, speed of collision, and fuel used. To reach net power, fusion reactions have to occur fast enough to make up for energy losses. Any power plant using fusion will hold in this hot cloud. Plasma clouds lose energy through conduction and radiation . Conduction

2800-575: A house at 2910 Derby Street, from which he applied for his first television patent, which was granted on August 26, 1930. By that time they had moved across the bay to San Francisco, where Farnsworth set up his new lab at 202 Green Street. A few months after arriving in California, Farnsworth was prepared to show his models and drawings to a patent attorney who was nationally recognized as an authority on electrophysics . Everson and Gorrell agreed that Farnsworth should apply for patents for his designs,

2940-468: A microscopic particle with a deterministic outcome, for instance. Such situations are encountered in radar scattering as well, where the targets tend to be macroscopic objects such as people or aircraft. Similarly, multiple scattering can sometimes have somewhat random outcomes, particularly with coherent radiation. The random fluctuations in the multiply scattered intensity of coherent radiation are called speckles . Speckle also occurs if multiple parts of

SECTION 20

#1732787256948

3080-437: A new trajectory, exit the grid at some new point, and accelerate back into the center again, providing the circulation that is required for a fusion event to eventually take place. It is important to consider the actual startup sequence of a fusor to understand the resulting operation. Normally the system is pumped down to a vacuum and then a small amount of gas is placed inside the vacuum chamber. This gas will spread out to fill

3220-447: A newly ionized atom of lower energy and thus cools the plasma. Scatterings may also increase the energy of an ion which allows it to move past the anode and escape, in this example anything above 15 keV. Additionally, the scatterings of both the ions, and especially impurities left in the chamber, lead to significant Bremsstrahlung , creating X-rays that carries energy out of the fuel. This effect grows with particle energy, meaning

3360-480: A pair of San Francisco philanthropists who were then conducting a Salt Lake City Community Chest fund-raising campaign. They agreed to fund his early television research with an initial $ 6,000 in backing, and set up a laboratory in Los Angeles for Farnsworth to carry out his experiments. Farnsworth married Pem on May 27, 1926, and the two traveled to Berkeley, California , in a Pullman coach. They rented

3500-409: A particular point. One of the biggest problems in fusion research is to keep the hot fuel from hitting the walls of the container. If this is allowed to happen, the fuel cannot be kept hot enough for the fusion reaction to occur. Farnsworth reasoned that he could build an electrostatic plasma confinement system in which the "wall" fields of the reactor were electrons or ions being held in place by

3640-454: A plasma consists of free-moving charges, it can be controlled using magnetic and electrical fields. Fusion devices use this capability to retain the fuel at millions of degrees. The fusor is part of a broader class of devices that attempts to give the fuel fusion-relevant energies by directly accelerating the ions toward each other. In the case of the fusor, this is accomplished with electrostatic forces. For every volt that an ion of ±1 charge

3780-526: A power plant seems destined to also destroy its inner electrode. As one fundamental limitation, any method which produces a neutron flux that is captured to heat a working fluid will also bombard its electrodes with that flux, heating them as well. Attempts to resolve these problems include Bussard 's Polywell system, D. C. Barnes' modified Penning trap approach, and the University of Illinois's fusor which retains grids but attempts to more tightly focus

3920-401: A practical power source. However, as with other fusion experiments, development into a power source has proven difficult. Nevertheless, the fusor has since become a practical neutron source and is produced commercially for this role. At the time he died, Farnsworth held 300 U.S. and foreign patents . His inventions contributed to the development of radar, infra-red night vision devices,

4060-426: A reactor similar in design to the fusor, now called the polywell , that he stated would be capable of useful power generation. Most recently, the fusor has gained popularity among amateurs, who choose them as home projects due to their relatively low space, money, and power requirements. An online community of "fusioneers", The Open Source Fusor Research Consortium, or Fusor.net, is dedicated to reporting developments in

4200-415: A relative's 240-acre (1.0 km ) ranch near Rigby, Idaho , where his father supplemented his farming income by hauling freight with his horse-drawn wagon. Philo was excited to find that his new home was wired for electricity, with a Delco generator providing power for lighting and farm machinery. He was a quick student in mechanical and electrical technology , repairing the troublesome generator. He found

4340-708: A small sample includes particles , bubbles , droplets , density fluctuations in fluids , crystallites in polycrystalline solids, defects in monocrystalline solids, surface roughness , cells in organisms, and textile fibers in clothing. The effects of such features on the path of almost any type of propagating wave or moving particle can be described in the framework of scattering theory . Some areas where scattering and scattering theory are significant include radar sensing, medical ultrasound , semiconductor wafer inspection, polymerization process monitoring, acoustic tiling, free-space communications and computer-generated imagery . Particle-particle scattering theory

Fusor - Misplaced Pages Continue

4480-465: A special kind of scattering experiment in particle physics. In mathematics , scattering theory deals with a more abstract formulation of the same set of concepts. For example, if a differential equation is known to have some simple, localized solutions, and the solutions are a function of a single parameter, that parameter can take the conceptual role of time . One then asks what might happen if two such solutions are set up far away from each other, in

4620-588: A varying electrical signal corresponding to the variations in light intensity . Farnsworth recognized the limitations of the mechanical systems, and that an all-electronic scanning system could produce a superior image for transmission to a receiving device. On September 7, 1927, Farnsworth's image dissector camera tube transmitted its first image, a simple straight line, to a receiver in another room of his laboratory at 202 Green Street in San Francisco . Pem Farnsworth recalled in 1985 that her husband broke

4760-465: A viable concept for large-scale energy production by scientists. Fusion takes place when nuclei approach to a distance where the nuclear force can pull them together into a single larger nucleus. Opposing this close approach are the positive charges in the nuclei, which force them apart due to the electrostatic force . In order to produce fusion events, the nuclei must have initial energy great enough to allow them to overcome this Coulomb barrier . As

4900-470: Is a common example where both spectral absorption and scattering play important and complex roles in the coloration. Light scattering can also create color without absorption, often shades of blue, as with the sky (Rayleigh scattering), the human blue iris , and the feathers of some birds (Prum et al. 1998). However, resonant light scattering in nanoparticles can produce many different highly saturated and vibrant hues, especially when surface plasmon resonance

5040-474: Is a framework for studying and understanding the scattering of waves and particles . Wave scattering corresponds to the collision and scattering of a wave with some material object, for instance (sunlight) scattered by rain drops to form a rainbow . Scattering also includes the interaction of billiard balls on a table, the Rutherford scattering (or angle change) of alpha particles by gold nuclei ,

5180-420: Is a major cause of the attenuation of radiation by the atmosphere . The degree of scattering varies as a function of the ratio of the particle diameter to the wavelength of the radiation, along with many other factors including polarization , angle, and coherence . For larger diameters, the problem of electromagnetic scattering by spheres was first solved by Gustav Mie , and scattering by spheres larger than

5320-578: Is a wide range of physical processes where moving particles or radiation of some form, such as light or sound , are forced to deviate from a straight trajectory by localized non-uniformities (including particles and radiation) in the medium through which they pass. In conventional use, this also includes deviation of reflected radiation from the angle predicted by the law of reflection . Reflections of radiation that undergo scattering are often called diffuse reflections and unscattered reflections are called specular (mirror-like) reflections. Originally,

5460-418: Is accelerated across it gains 1 electronvolt in energy. To reach the required ~10 keV, a voltage of 10 kV is required, applied to both particles. For comparison, the electron gun in a typical television cathode-ray tube is on the order of 3 to 6 kV, so the complexity of such a device is fairly limited. For a variety of reasons, energies on the order of 15 keV are used. This corresponds to

5600-417: Is an interaction coefficient and x is the distance traveled in the target. The above ordinary first-order differential equation has solutions of the form: where I o is the initial flux, path length Δx ≡  x  −  x o , the second equality defines an interaction mean free path λ, the third uses the number of targets per unit volume η to define an area cross-section σ, and

5740-552: Is characterized by a broad symmetric glow, with one or two electron beams exiting the structure. There is little fusion. The halo mode occurs in higher pressure tanks, and as the vacuum improves, the device transitions to star mode. Star mode appears as bright beams of light emanating from the device center. Because the electric field made by the cages is negative, it cannot simultaneously trap both positively charged ions and negative electrons. Hence, there must be some regions of charge accumulation , which will result in an upper limit on

Fusor - Misplaced Pages Continue

5880-541: Is important in areas such as particle physics , atomic, molecular, and optical physics , nuclear physics and astrophysics . In particle physics the quantum interaction and scattering of fundamental particles is described by the Scattering Matrix or S-Matrix , introduced and developed by John Archibald Wheeler and Werner Heisenberg . Scattering is quantified using many different concepts, including scattering cross section (σ), attenuation coefficients ,

6020-414: Is involved (Roqué et al. 2006). Models of light scattering can be divided into three domains based on a dimensionless size parameter, α which is defined as: α = π D p / λ , {\displaystyle \alpha =\pi D_{\text{p}}/\lambda ,} where πD p is the circumference of a particle and λ is the wavelength of incident radiation in

6160-400: Is not applicable to IEC fusion, as a quasineutral plasma cannot be contained by an electric field, which is a fundamental part of IEC fusion. However, in an earlier paper, "A general critique of inertial-electrostatic confinement fusion systems" , Rider addresses the common IEC devices directly, including the fusor. In the case of the fusor the electrons are generally separated from the mass of

6300-419: Is one of the two major physical processes that contribute to the visible appearance of most objects, the other being absorption. Surfaces described as white owe their appearance to multiple scattering of light by internal or surface inhomogeneities in the object, for example by the boundaries of transparent microscopic crystals that make up a stone or by the microscopic fibers in a sheet of paper. More generally,

6440-405: Is particularly important. Several different aspects of electromagnetic scattering are distinct enough to have conventional names. Major forms of elastic light scattering (involving negligible energy transfer) are Rayleigh scattering and Mie scattering . Inelastic scattering includes Brillouin scattering , Raman scattering , inelastic X-ray scattering and Compton scattering . Light scattering

6580-545: Is simple to demonstrate that the scattering chance is many orders of magnitude higher than the fusion rate, meaning that the vast majority of the energy supplied to the ions will go to waste and those fusion reactions that do occur cannot make up for these losses. To be energy positive, a fusion device must recycle these ions back into the fuel mass so that they have thousands or millions of such chances to fuse, and their energy must be retained as much as possible during this period. The fusor attempts to meet this requirement through

6720-434: Is that single scattering can usually be treated as a random phenomenon, whereas multiple scattering, somewhat counterintuitively, can be modeled as a more deterministic process because the combined results of a large number of scattering events tend to average out. Multiple scattering can thus often be modeled well with diffusion theory . Because the location of a single scattering center is not usually well known relative to

6860-515: Is the inverse scattering transform , central to the solution of many exactly solvable models . In mathematical physics , scattering theory is a framework for studying and understanding the interaction or scattering of solutions to partial differential equations . In acoustics , the differential equation is the wave equation , and scattering studies how its solutions, the sound waves , scatter from solid objects or propagate through non-uniform media (such as sound waves, in sea water , coming from

7000-409: Is therefore often described by probability distributions. With multiple scattering, the randomness of the interaction tends to be averaged out by a large number of scattering events, so that the final path of the radiation appears to be a deterministic distribution of intensity. This is exemplified by a light beam passing through thick fog . Multiple scattering is highly analogous to diffusion , and

7140-410: Is when ions , electrons or neutrals touch a surface and leak out. Energy is lost with the particle. Radiation is when energy leaves the cloud as light. Radiation increases as the temperature rises. To get net power from fusion it's necessary to overcome these losses. This leads to an equation for power output. where: John Lawson used this equation to estimate some conditions for net power based on

SECTION 50

#1732787256948

7280-469: The 1936 Olympic Games in Berlin . Farnsworth returned to his laboratory, and by 1936 his company was regularly transmitting entertainment programs on an experimental basis. That same year, while working with University of Pennsylvania biologists , Farnsworth developed a process to sterilize milk using radio waves. He also invented a fog-penetrating beam for ships and airplanes. In 1936, he attracted

7420-540: The United States Naval Academy in Annapolis , Maryland , where he earned the nation's second-highest score on academy recruiting tests. However, he was already thinking ahead to his television projects; he learned that the government would own his patents if he stayed in the military, so he obtained an honorable discharge within months of joining under a provision in which the eldest child in

7560-840: The University of Wisconsin–Madison , the Massachusetts Institute of Technology and government entities, such as the Atomic Energy Organization of Iran and the Turkish Atomic Energy Authority . Fusors have also been developed commercially, as sources for neutrons by DaimlerChrysler Aerospace and as a method for generating medical isotopes. Fusors have also become very popular for hobbyists and amateurs. A growing number of amateurs have performed nuclear fusion using simple fusor machines. However, fusors are not considered

7700-434: The bidirectional scattering distribution function (BSDF), S-matrices , and mean free path . When radiation is only scattered by one localized scattering center, this is called single scattering . It is more common that scattering centers are grouped together; in such cases, radiation may scatter many times, in what is known as multiple scattering . The main difference between the effects of single and multiple scattering

7840-527: The bound state solutions of some differential equation. Thus, for example, the hydrogen atom corresponds to a solution to the Schrödinger equation with a negative inverse-power (i.e., attractive Coulombic) central potential . The scattering of two hydrogen atoms will disturb the state of each atom, resulting in one or both becoming excited, or even ionized , representing an inelastic scattering process. The term " deep inelastic scattering " refers to

7980-499: The electron microscope , the baby incubator , the gastroscope , and the astronomical telescope . Although he was the man responsible for its technology, Farnsworth appeared only once on a television program. On July 3, 1957, he was a mystery guest ("Doctor X") on the CBS quiz show I've Got A Secret . He fielded questions from the panel as they unsuccessfully tried to guess his secret ("I invented electronic television."). For stumping

8120-459: The gloss (or lustre or sheen ) of the surface is determined by scattering. Highly scattering surfaces are described as being dull or having a matte finish, while the absence of surface scattering leads to a glossy appearance, as with polished metal or stone. Spectral absorption, the selective absorption of certain colors, determines the color of most objects with some modification by elastic scattering . The apparent blue color of veins in skin

8260-413: The mass attenuation coefficient (e.g. in cm /gram) or area per nucleon are all popular, while in electron microscopy the inelastic mean free path (e.g. λ in nanometers) is often discussed instead. The term "elastic scattering" implies that the internal states of the scattering particles do not change, and hence they emerge unchanged from the scattering process. In inelastic scattering, by contrast,

8400-436: The multipactor . Fuel could then be injected through the wall, and once inside it would be unable to escape. He called this concept a virtual electrode, and the system as a whole the fusor . Farnsworth's original fusor designs were based on cylindrical arrangements of electrodes, like the original multipactors. Fuel was ionized and then fired from small accelerators through holes in the outer (physical) electrodes. Once through

8540-493: The neutron generator easily sits on a benchtop, and can be turned off at the flick of a switch. A commercial fusor was developed as a non-core business within DaimlerChrysler Aerospace – Space Infrastructure, Bremen between 1996 and early 2001. After the project was effectively ended, the former project manager established a company which is called NSD-Fusion. To date, the highest neutron flux achieved by

SECTION 60

#1732787256948

8680-459: The " Time 100: The Most Important People of the Century ". Farnsworth worked out the principle of the image dissector in the summer of 1921, not long before his 15th birthday, and demonstrated the first working version on September 7, 1927, having turned 21 the previous August. A farm boy, his inspiration for scanning an image as a series of lines came from the back-and-forth motion used to plow

8820-424: The "distant past", and are made to move towards each other, interact (under the constraint of the differential equation) and then move apart in the "future". The scattering matrix then pairs solutions in the "distant past" to those in the "distant future". Solutions to differential equations are often posed on manifolds . Frequently, the means to the solution requires the study of the spectrum of an operator on

8960-417: The "electron gun" which forms the basis for old-style television display tubes), as well as magnetron type devices, (which are the power sources for microwave ovens), which can enhance ion formation using high-voltage electromagnetic fields. Any method which increases ion density (within limits which preserve ion mean-free path), or ion energy, can be expected to enhance the fusion yield, typically measured in

9100-529: The $ 24,000 a month required for salaries and equipment rental. In a 1996 videotaped interview by the Academy of Television Arts & Sciences , Farnsworth's wife recounted his change of heart about the value of television, after seeing Neil Armstrong becoming the first person to walk on the Moon in real time on July 20, 1969, along with millions of others: "We were watching it, and, when Neil Armstrong landed on

9240-462: The 1870s. Near the end of the 19th century, the scattering of cathode rays (electron beams) and X-rays was observed and discussed. With the discovery of subatomic particles (e.g. Ernest Rutherford in 1911 ) and the development of quantum theory in the 20th century, the sense of the term became broader as it was recognized that the same mathematical frameworks used in light scattering could be applied to many other phenomena. Scattering can refer to

9380-492: The 1950s was the forerunner of today's air traffic control systems. In addition to his electronics research, ITT management agreed to nominally fund Farnsworth's nuclear fusion research. He and staff members invented and refined a series of fusion reaction tubes called " fusors ". For scientific reasons unknown to Farnsworth and his staff, the necessary reactions lasted no longer than thirty seconds. In December 1965, ITT came under pressure from its board of directors to terminate

9520-504: The AEC decided to concentrate funding on large tokamak projects, and reduce backing for alternative concepts. George H. Miley at the University of Illinois reexamined the fusor and re-introduced it into the field. A low but steady interest in the fusor has persisted since. An important development was the successful commercial introduction of a fusor-based neutron generator . From 2006 until his death in 2007, Robert W. Bussard gave talks on

9660-467: The Bragg scattering (or diffraction) of electrons and X-rays by a cluster of atoms, and the inelastic scattering of a fission fragment as it traverses a thin foil. More precisely, scattering consists of the study of how solutions of partial differential equations , propagating freely "in the distant past", come together and interact with one another or with a boundary condition , and then propagate away "to

9800-617: The Farnsworth Television and Radio Corporation from 1938 to 1951, in Fort Wayne, Indiana . In later life, Farnsworth invented a small nuclear fusion device, the Farnsworth Fusor , employing inertial electrostatic confinement (IEC). Like many fusion devices, it was not a practical device for generating nuclear power , although it provides a viable source of neutrons . The design of this device has been

9940-543: The Farnsworth Television and Radio Corporation in Fort Wayne, Indiana, with E. A. Nicholas as president and himself as director of research. In September 1939, after a more than decade-long legal battle, RCA finally conceded to a multi-year licensing agreement concerning Farnsworth's 1927 patent for television totaling $ 1 million. RCA was then free, after showcasing electronic television at New York World's Fair on April 20, 1939, to sell electronic television cameras to

10080-581: The Image Dissector (filed April 26, 1933) features the "charge storage plate" invented by Tihanyi in 1928 and a "low velocity" method of electron scanning, also describes "discrete particles" whose "potential" is manipulated and "saturated" to varying degrees depending on their velocity. Farnsworth's patent numbers 2,140,695 and 2,233,888 are for a "charge storage dissector" and "charge storage amplifier," respectively. In 1931, David Sarnoff of RCA offered to buy Farnsworth's patents for $ 100,000, with

10220-587: The Rayleigh range is therefore usually known as Mie scattering. In the Mie regime, the shape of the scattering center becomes much more significant and the theory only applies well to spheres and, with some modification, spheroids and ellipsoids . Closed-form solutions for scattering by certain other simple shapes exist, but no general closed-form solution is known for arbitrary shapes. Both Mie and Rayleigh scattering are considered elastic scattering processes, in which

10360-513: The achievable density. This could place an upper limit on the machine's power density, which may keep it too low for power production. When they first fall into the center of the fusor, the ions will all have the same energy, but the velocity distribution will rapidly approach a Maxwell–Boltzmann distribution . This would occur through simple Coulomb collisions in a matter of milliseconds, but beam-beam instabilities will occur orders of magnitude faster still. In comparison, any given ion will require

10500-574: The air." KID-TV, which later became KIDK-TV, was then located near the Rigby area where Farnsworth grew up. In 2010, the former Farnsworth factory in Fort Wayne, Indiana, was razed, eliminating the "cave," where many of Farnsworth's inventions were first created, and where its radio and television receivers and transmitters, television tubes, and radio-phonographs were mass-produced under the Farnsworth, Capehart, and Panamuse trade names. The facility

10640-448: The attention of Collier's Weekly , which described his work in glowing terms. "One of those amazing facts of modern life that just don't seem possible—namely, electrically scanned television that seems destined to reach your home next year, was largely given to the world by a nineteen-year-old boy from Utah ... Today, barely thirty years old he is setting the specialized world of science on its ears." In 1938, Farnsworth established

10780-403: The average kinetic energy at a temperature of approximately 174 million Kelvin, a typical magnetic confinement fusion plasma temperature. The problem with this colliding beam fusion approach, in general, is that the ions will most likely never hit each other no matter how precisely aimed. Even the most minor misalignment will cause the particles to scatter and thus fail to fuse. It

10920-949: The bright lighting required). Many inventors had built electromechanical television systems before Farnsworth's seminal contribution, but Farnsworth designed and built the world's first working all-electronic television system, employing electronic scanning in both the pickup and display devices. He first demonstrated his system to the press on September 3, 1928, and to the public at the Franklin Institute in Philadelphia on August 25, 1934. In 1930, RCA recruited Vladimir K. Zworykin —who had tried, unsuccessfully, to develop his own all-electronic television system at Westinghouse in Pittsburgh since 1923 —to lead its television development department. Before leaving his old employer, Zworykin visited Farnsworth's laboratory, and

11060-440: The cloud lose energy as light. The radiation from a fusor can (at least) be in the visible , ultraviolet and X-ray spectrum, depending on the type of fusor used. These changes in speed can be due to electrostatic interactions between particles (ion to ion, ion to electron, electron to electron). This is referred to bremsstrahlung radiation, and is common in fusors. Changes in speed can also be due to interactions between

11200-425: The combined work of Farnsworth, Zworykin, and many others was used in all television cameras until the late 20th century, when alternate technologies such as charge-coupled devices began to appear. Farnsworth also developed the "image oscillite", a cathode ray tube that displayed the images captured by the image dissector. Farnsworth called his device an image dissector because it converted individual elements of

11340-552: The consequences of particle-particle collisions between molecules, atoms, electrons , photons and other particles. Examples include: cosmic ray scattering in the Earth's upper atmosphere; particle collisions inside particle accelerators ; electron scattering by gas atoms in fluorescent lamps; and neutron scattering inside nuclear reactors . The types of non-uniformities which can cause scattering, sometimes known as scatterers or scattering centers , are too numerous to list, but

11480-425: The core. These form because the forces within the region correspond to roughly stable "orbits". Approximately 40% of the high energy ions in a typical grid operating in star mode may be within these microchannels. Nonetheless, grid collisions remain the primary energy loss mechanism for Farnsworth–Hirsch fusors. Complicating issues is the challenge in cooling the central electrode; any fusor producing enough power to run

11620-457: The critical contributions to electronic television that made possible all the video in the world today. He is best known for his 1927 invention of the first fully functional all-electronic image pickup device ( video camera tube ), the image dissector , as well as the first fully functional and complete all-electronic television system. Farnsworth developed a television system complete with receiver and camera—which he produced commercially through

11760-405: The distant future". The direct scattering problem is the problem of determining the distribution of scattered radiation/particle flux basing on the characteristics of the scatterer. The inverse scattering problem is the problem of determining the characteristics of an object (e.g., its shape, internal constitution) from measurement data of radiation or particles scattered from the object. When

11900-405: The distribution of the scattered electromagnetic field. Sophisticated software packages exist which allow the user to specify the refractive index or indices of the scattering feature in space, creating a 2- or sometimes 3-dimensional model of the structure. For relatively large and complex structures, these models usually require substantial execution times on a computer. Electrophoresis involves

12040-571: The drawings that he did on a blackboard for his chemistry teacher was recalled and reproduced for a patent interference case between Farnsworth and RCA . In 1923, the family moved to Provo, Utah , and Farnsworth attended Brigham Young High School that fall. His father died of pneumonia in January 1924 at age 58, and Farnsworth assumed responsibility for sustaining the family while finishing high school. After graduating BYHS in June 1924, he applied to

12180-542: The electrodes needs to be at least 25 kV for fusion to occur. All of this work had taken place at the Farnsworth Television labs , which had been purchased in 1949 by ITT Corporation , as part of its plan to become the next RCA . However, a fusion research project was not regarded as immediately profitable. In 1965, the board of directors started asking Harold Geneen to sell off the Farnsworth division, but he had his 1966 budget approved with funding until

12320-456: The energy (and thus wavelength and frequency) of the light is not substantially changed. However, electromagnetic radiation scattered by moving scattering centers does undergo a Doppler shift , which can be detected and used to measure the velocity of the scattering center/s in forms of techniques such as lidar and radar . This shift involves a slight change in energy. At values of the ratio of particle diameter to wavelength more than about 10,

12460-407: The energy needed in a fusor system is higher than one where the fuel is heated by some other method, as some will be "lost" during startup. Real electrodes are not infinitely thin, and the potential for scattering off the wires or even capture of the ions within the electrodes is a significant issue that causes high conduction losses. These losses can be at least five orders of magnitude higher than

12600-429: The energy released from the fusion reaction, even when the fusor is in star mode, which minimizes these reactions. There are numerous other loss mechanisms as well. These include charge exchange between high-energy ions and low-energy neutral particles, which causes the ion to capture the electron, become electrically neutral, and then leave the fusor as it is no longer accelerated back into the chamber. This leaves behind

12740-635: The expensive project and sell the Farnsworth subsidiary. It was only due to the urging of president Harold Geneen that the 1966 budget was accepted, extending ITT's fusion research for an additional year. The stress associated with this managerial ultimatum, however, caused Farnsworth to suffer a relapse. A year later he was terminated and eventually allowed medical retirement. In 1967, Farnsworth and his family moved back to Utah to continue his fusion research at Brigham Young University , which presented him with an honorary doctorate. The university also offered him office space and an underground concrete bunker for

12880-691: The family home and the second-floor boarding house, with the help of a cousin living with the family. The Farnsworths later moved into half of a duplex, with family friends the Gardners moving into the other side when it became vacant. He developed a close friendship with Pem's brother Cliff Gardner, who shared his interest in electronics, and the two moved to Salt Lake City to start a radio repair business. The business failed, and Gardner returned to Provo. Farnsworth remained in Salt Lake City and became acquainted with Leslie Gorrell and George Everson,

13020-406: The far side of the central reaction area. The fuel atoms inside the inner area during the startup period are not ionized. The accelerated ions scatter with these and lose their energy, while ionizing the formerly cold atom. This process, and the scatterings off other ions, causes the ion energies to become randomly distributed and the fuel rapidly takes on a non-thermal distribution. For this reason,

13160-421: The fuel isolated near the electrodes, which limits the loss rate. However, Rider demonstrates that practical fusors operate in a range of modes that either lead to significant electron mixing and losses, or alternately lower power densities. This appears to be a sort of catch-22 that limits the output of any fusor-like system. There are several key safety considerations involved with the building and operation of

13300-610: The fuel to temperatures where the Maxwell-Boltzmann distribution of their resulting energies is high enough that some of the particles in the long tail have the required energy. High enough in this case is such that the rate of the fusion reactions produces enough energy to offset energy losses to the environment and thus heat the surrounding fuel to the same temperatures and produce a self-sustaining reaction known as ignition . Calculations show this takes place at about 50 million  kelvin (K), although higher numbers on

13440-400: The fusor injects high-temperature ions directly into a reaction chamber, thereby avoiding a considerable amount of complexity. When the Farnsworth fusor was first introduced to the fusion research world in the late 1960s, the fusor was the first device that could clearly demonstrate it was producing fusion reactions at all. Hopes at the time were high that it could be quickly developed into

13580-410: The gas molecules move around, which are normally small enough in scale for Rayleigh's model to apply. This scattering mechanism is the primary cause of the blue color of the Earth's sky on a clear day, as the shorter blue wavelengths of sunlight passing overhead are more strongly scattered than the longer red wavelengths according to Rayleigh's famous 1/ λ relation. Along with absorption, such scattering

13720-401: The hole they were accelerated towards the inner reaction area at high velocity. Electrostatic pressure from the positively charged electrodes would keep the fuel as a whole off the walls of the chamber, and impacts from new ions would keep the hottest plasma in the center. He referred to this as inertial electrostatic confinement , a term that continues to be used to this day. The voltage between

13860-478: The image into electricity one at a time. He replaced the spinning disks with cesium, an element that emits electrons when exposed to light. In 1984, Farnsworth was inducted into the National Inventors Hall of Fame . The Farnsworth fusor is an apparatus designed by Farnsworth to create nuclear fusion. Unlike most controlled fusion systems, which slowly heat a magnetically confined plasma ,

14000-530: The inspiration for other fusion approaches, including the Polywell reactor concept. Farnsworth held 300 patents, mostly in radio and television. Farnsworth was born August 19, 1906, the eldest of five children of Lewis Edwin Farnsworth and Serena Amanda Bastian, a Latter-day Saint couple living in a small log cabin built by Lewis' father in Manderfield, near Beaver, Utah . In 1918, the family moved to

14140-414: The invention; so the first image shown was, appropriately, a dollar sign. In 1929, the design was further improved by elimination of a motor-generator , which meant the television system now had no mechanical parts. During the same year, Farnsworth transmitted the first live human images with his system, including a 3.5 in (89 mm) image of his wife Elma ("Pem") with her eyes closed (possibly due to

14280-617: The ions fuse before losing their energy by any process). Whereas 45 megakelvins is a very high temperature by any standard, the corresponding voltage is only 4 kV, a level commonly found in such devices as neon signs and CRT televisions. To the extent that the ions remain at their initial energy, the energy can be tuned to take advantage of the peak of the reaction cross section or to avoid disadvantageous (for example neutron-producing) reactions that might occur at higher energies. Various attempts have been made at increasing deuterium ionization rate, including heaters within "ion-guns", (similar to

14420-542: The ions into microchannels to attempt to avoid losses. While all three are Inertial electrostatic confinement (IEC) devices, only the last is actually a "fusor". Charged particles will radiate energy as light when they change velocity. This loss rate can be estimated for nonrelativistic particles using the Larmor formula . Inside a fusor there is a cloud of ions and electrons . These particles will accelerate or decelerate as they move about. These changes in speed make

14560-425: The ions must be at a temperature of at least 4 keV ( kiloelectronvolts ), or about 45 million kelvins . The second easiest reaction is fusing deuterium with itself. Because this gas is cheaper, it is the fuel commonly used by amateurs. The ease of doing a fusion reaction is measured by its cross section . At such conditions, the atoms are ionized and make a plasma . The energy generated by fusion, inside

14700-561: The last uses the target mass density ρ to define a density mean free path τ. Hence one converts between these quantities via Q = 1/ λ =  ησ =  ρ/τ , as shown in the figure at left. In electromagnetic absorption spectroscopy, for example, interaction coefficient (e.g. Q in cm ) is variously called opacity , absorption coefficient , and attenuation coefficient . In nuclear physics, area cross-sections (e.g. σ in barns or units of 10 cm ), density mean free path (e.g. τ in grams/cm ), and its reciprocal

14840-485: The laws of geometric optics are mostly sufficient to describe the interaction of light with the particle. Mie theory can still be used for these larger spheres, but the solution often becomes numerically unwieldy. For modeling of scattering in cases where the Rayleigh and Mie models do not apply such as larger, irregularly shaped particles, there are many numerical methods that can be used. The most common are finite-element methods which solve Maxwell's equations to find

14980-484: The manifold. As a result, the solutions often have a spectrum that can be identified with a Hilbert space , and scattering is described by a certain map, the S matrix , on Hilbert spaces. Solutions with a discrete spectrum correspond to bound states in quantum mechanics, while a continuous spectrum is associated with scattering states. The study of inelastic scattering then asks how discrete and continuous spectra are mixed together. An important, notable development

15120-416: The medium. Based on the value of α , these domains are: Rayleigh scattering is a process in which electromagnetic radiation (including light) is scattered by a small spherical volume of variant refractive indexes, such as a particle, bubble, droplet, or even a density fluctuation. This effect was first modeled successfully by Lord Rayleigh , from whom it gets its name. In order for Rayleigh's model to apply,

15260-408: The middle of 1967. Further funding was refused, and that ended ITT's experiments with fusion. Things changed dramatically with the arrival of Robert Hirsch , and the introduction of the modified Hirsch–Meeks fusor patent. New fusors based on Hirsch's design were first constructed between 1964 and 1967. Hirsch published his design in a paper in 1967. His design included ion beams to shoot ions into

15400-524: The moon, Phil turned to me and said, 'Pem, this has made it all worthwhile.' Before then, he wasn't too sure." By Christmas 1970, PTFA had failed to secure the necessary financing, and the Farnsworths had sold all their own ITT stock and cashed in Philo's life insurance policy to maintain organizational stability. The underwriter had failed to provide the financial backing that was to have supported

15540-432: The nuclear force is increased with the number of nucleons, protons and neutrons, and the electromagnetic force is increased with the number of protons only, the easiest atoms to fuse are isotopes of hydrogen, deuterium with one neutron, and tritium with two. With hydrogen fuels, about 3 to 10 keV is needed to allow the reaction to take place. Traditional approaches to fusion power have generally attempted to heat

15680-435: The number of neutrons produced per second. The ease with which the ion energy can be increased appears to be particularly useful when "high temperature" fusion reactions are considered, such as proton-boron fusion , which has plentiful fuel, requires no radioactive tritium , and produces no neutrons in the primary reaction. Fusors have at least two modes of operation (possibly more): star mode and halo mode . Halo mode

15820-441: The order of 100 million K are desirable in practical machines. Due to the extremely high temperatures, fusion reactions are also referred to as thermo nuclear. When atoms are heated to temperatures corresponding to thousands of degrees, the electrons become increasingly free of their nucleus. This leads to a gas-like state of matter known as a plasma , consisting of free nuclei known as ions, and their former electrons. As

15960-1120: The organization during its critical first year. The banks called in all outstanding loans, repossession notices were placed on anything not previously sold, and the Internal Revenue Service put a lock on the laboratory door until delinquent taxes were paid. In January 1971, PTFA disbanded. Farnsworth had begun abusing alcohol in his later years, and as a result became seriously ill with pneumonia , and died on March 11, 1971, at his home in Holladay, Utah . Farnsworth's wife Elma Gardner "Pem" Farnsworth fought for decades after his death to assure his place in history. Farnsworth always gave her equal credit for creating television, saying, "my wife and I started this TV." She died on April 27, 2006, at age 98. The inventor and wife were survived by two sons, Russell (then living in New York City), and Kent (then living in Fort Wayne, Indiana). In 1999, Time magazine included Farnsworth in

16100-432: The panel, he received $ 80 and a carton of Winston cigarettes. Host Garry Moore then spent a few minutes discussing with Farnsworth his research on such projects as an early analog high-definition television system , flat-screen receivers, and fusion power. Farnsworth said, "There had been attempts to devise a television system using mechanical disks and rotating mirrors and vibrating mirrors—all mechanical. My contribution

16240-445: The particle and the electric field. Since there are no magnetic fields, fusors emit no cyclotron radiation at slow speeds, or synchrotron radiation at high speeds. In Fundamental limitations on plasma fusion systems not in thermodynamic equilibrium , Todd Rider argues that a quasineutral isotropic plasma will lose energy due to Bremsstrahlung at a rate prohibitive for any fuel other than D-T (or possibly D-D or D-He3). This paper

16380-490: The particles' internal state is changed, which may amount to exciting some of the electrons of a scattering atom, or the complete annihilation of a scattering particle and the creation of entirely new particles. The example of scattering in quantum chemistry is particularly instructive, as the theory is reasonably complex while still having a good foundation on which to build an intuitive understanding. When two atoms are scattered off one another, one can understand them as being

16520-443: The path of the radiation, the outcome, which tends to depend strongly on the exact incoming trajectory, appears random to an observer. This type of scattering would be exemplified by an electron being fired at an atomic nucleus. In this case, the atom's exact position relative to the path of the electron is unknown and would be unmeasurable, so the exact trajectory of the electron after the collision cannot be predicted. Single scattering

16660-419: The problem becomes more pronounced as the system approaches fusion-relevant operating conditions. As a result of these loss mechanisms, no fusor has ever come close to break-even energy output and it appears it is unable to ever do so. The common sources of the high voltage are ZVS flyback HV sources and neon-sign transformers . It can also be called an electrostatic particle accelerator . The fusor

16800-519: The products are most likely to fly off to and how quickly. They also reveal the probability of various reactions, creations, and decays occurring. There are two predominant techniques of finding solutions to scattering problems: partial wave analysis , and the Born approximation . Electromagnetic waves are one of the best known and most commonly encountered forms of radiation that undergo scattering. Scattering of light and radio waves (especially in radar)

16940-515: The project. Realizing ITT would dismantle its fusion lab, Farnsworth invited staff members to accompany him to Salt Lake City , as team members in Philo T. Farnsworth Associates (PTFA). By late 1968, the associates began holding regular business meetings and PTFA was underway. They promptly secured a contract with the National Aeronautics and Space Administration (NASA) , and more possibilities were within reach—but financing stalled for

17080-452: The public. Farnsworth Television and Radio Corporation was purchased by International Telephone and Telegraph (ITT) in 1951. During his time at ITT, Farnsworth worked in a basement laboratory known as "the cave" on Pontiac Street in Fort Wayne. From there, he introduced a number of breakthrough concepts, including a defense early warning signal, submarine detection devices, radar calibration equipment and an infrared telescope . "Philo

17220-853: The relevant equation is the Schrödinger equation , although equivalent formulations, such as the Lippmann-Schwinger equation and the Faddeev equations , are also largely used. The solutions of interest describe the long-term motion of free atoms, molecules, photons, electrons, and protons. The scenario is that several particles come together from an infinite distance away. These reagents then collide, optionally reacting, getting destroyed or creating new particles. The products and unused reagents then fly away to infinity again. (The atoms and molecules are effectively particles for our purposes. Also, under everyday circumstances, only photons are being created and destroyed.) The solutions reveal which directions

17360-656: The southwest corner of E. State and St. Joseph Blvds. The residence is recognized by an Indiana state historical marker and was listed on the National Register of Historic Places in 2013. In addition to Fort Wayne, Farnsworth operated a factory in Marion, Indiana , that made shortwave radios used by American combat soldiers in World War II. Acquired by RCA after the war, the facility was located at 3301 S. Adams St. Scattering In physics, scattering

17500-437: The sphere must be much smaller in diameter than the wavelength ( λ ) of the scattered wave; typically the upper limit is taken to be about 1/10 the wavelength. In this size regime, the exact shape of the scattering center is usually not very significant and can often be treated as a sphere of equivalent volume. The inherent scattering that radiation undergoes passing through a pure gas is due to microscopic density fluctuations as

17640-421: The spherical arrangement of its accelerator grid system. Ions that fail to fuse pass through the center of the device and back into the accelerator on the far side, where they are accelerated back into the center again. There is no energy lost in this action, and in theory, assuming infinitely thin grid wires, the ions can circulate forever with no additional energy needed. Even those that scatter will simply take on

17780-465: The stipulation that he become an employee of RCA, but Farnsworth refused. In June of that year, Farnsworth joined the Philco company and moved to Philadelphia along with his wife and two children. RCA later filed an interference suit against Farnsworth, claiming Zworykin's 1923 patent had priority over Farnsworth's design, despite the fact it could present no evidence that Zworykin had actually produced

17920-419: The stunned silence of his lab assistants by saying, "There you are – electronic television!" The source of the image was a glass slide, backlit by an arc lamp . An extremely bright source was required because of the low light sensitivity of the design. By 1928, Farnsworth had developed the system sufficiently to hold a demonstration for the press. His backers had demanded to know when they would see dollars from

18060-476: The target is a set of many scattering centers whose relative position varies unpredictably, it is customary to think of a range equation whose arguments take different forms in different application areas. In the simplest case consider an interaction that removes particles from the "unscattered beam" at a uniform rate that is proportional to the incident number of particles per unit area per unit time ( I {\displaystyle I} ), i.e. that where Q

18200-463: The term was confined to light scattering (going back at least as far as Isaac Newton in the 17th century ). As more "ray"-like phenomena were discovered, the idea of scattering was extended to them, so that William Herschel could refer to the scattering of "heat rays" (not then recognized as electromagnetic in nature) in 1800. John Tyndall , a pioneer in light scattering research, noted the connection between light scattering and acoustic scattering in

18340-478: The terms multiple scattering and diffusion are interchangeable in many contexts. Optical elements designed to produce multiple scattering are thus known as diffusers . Coherent backscattering , an enhancement of backscattering that occurs when coherent radiation is multiply scattered by a random medium, is usually attributed to weak localization . Not all single scattering is random, however. A well-controlled laser beam can be exactly positioned to scatter off

18480-538: The vacuum chamber. The team then turned to the AEC , then in charge of fusion research funding, and provided them with a demonstration device mounted on a serving cart that produced more fusion than any existing "classical" device. The observers were startled, but the timing was bad; Hirsch himself had recently revealed the great progress being made by the Soviets using the tokamak . In response to this surprising development,

18620-484: The volume. When voltage is applied to the electrodes, the atoms between them will experience a field that will cause them to ionize and begin accelerating inward. As the atoms are randomly distributed to begin, the amount of energy they will gain differs; atoms initially near the anode will gain some large portion of the applied voltage, say 15 keV. Those initially near the cathode will gain much less energy, possibly far too low to undergo fusion with their counterparts on

18760-535: The world of fusors and aiding other amateurs in their projects. The site includes forums, articles and papers done on the fusor, including Farnsworth's original patent, as well as Hirsch's patent of his version of the invention. Nuclear fusion refers to reactions in which lighter nuclei are combined to become heavier nuclei. This process changes mass into energy which in turn may be captured to provide fusion power . Many types of atoms can be fused. The easiest to fuse are deuterium and tritium . For fusion to occur

18900-489: Was a very deep person—tough to engage in conversation, because he was always thinking about what he could do next", said Art Resler, an ITT photographer who documented Farnsworth's work in pictures. One of Farnsworth's most significant contributions at ITT was the PPI Projector , an enhancement on the iconic "circular sweep" radar display , which allowed safe air traffic control from the ground. This system developed in

19040-403: Was closer to this thing you're using now [i.e., a video camera] than anybody, because he used the cathode-ray tube for transmission. But, Farnsworth didn't have the mosaic [of discrete light elements], he didn't have storage. Therefore, [picture] definition was very low.... But he was very proud, and he stuck to his method." Contrary to Zworykin's statement, Farnsworth's patent number 2,087,683 for

19180-521: Was located at 3702 E. Pontiac St. Also that year, additional Farnsworth factory artifacts were added to the Fort Wayne History Center's collection, including a radio-phonograph and three table-top radios from the 1940s, as well as advertising and product materials from the 1930s to the 1950s. Farnsworth's Fort Wayne residence from 1948 to 1967, then the former Philo T. Farnsworth Television Museum , stands at 734 E. State Blvd, on

19320-404: Was originally conceived by Philo T. Farnsworth , better known for his pioneering work in television. In the early 1930s, he investigated a number of vacuum tube designs for use in television, and found one that led to an interesting effect. In this design, which he called the "multipactor", electrons moving from one electrode to another were stopped in mid-flight with the proper application of

19460-503: Was sufficiently impressed with the performance of the Image Dissector that he reportedly had his team at Westinghouse make several copies of the device for experimentation. Zworykin later abandoned research on the Image Dissector, which at the time required extremely bright illumination of its subjects, and turned his attention to what became the Iconoscope . In a 1970s series of videotaped interviews, Zworykin recalled that, "Farnsworth

19600-551: Was to take out the moving parts and make the thing entirely electronic, and that was the concept that I had when I was just a freshman in high school in the Spring of 1921 at age 14." A letter to the editor of the Idaho Falls Post Register disputed that Farnsworth had made only one television appearance. Roy Southwick claimed "... I interviewed Mr. [Philo] Farnsworth back in 1953—the first day KID-TV went on

#947052