query: who invented the photographic effect that is known as x-rays

pos: X-ray X-ray X-rays make up X-radiation, a form of electromagnetic radiation. Most X-rays have a wavelength ranging from 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3×10 Hz to 3×10 Hz) and energies in the range 100 eV to 100 keV. X-ray wavelengths are shorter than those of UV rays and typically longer than those of gamma rays. In many languages, X-radiation is referred to with terms meaning Röntgen radiation, after the German scientist Wilhelm Röntgen who discovered these on November 8, 1895, who usually is credited as its discoverer, and who named it

pos: ADOX ADOX ADOX was originally a brand name used by the German company, Fotowerke Dr. C. Schleussner GmbH of Frankfurt am Main, the world's first photographic materials manufacturer. The company's founder, Dr. Carl Schleussner, did pioneering work on the wet-collodion process during the early years of photography, and formed his manufacturing company in 1860. Working with the physicist Wilhelm Röntgen, discoverer of X-rays, Dr. Schleussner invented the first X-ray plate. The Schleussner firm began marketing cameras under the ADOX brand name in the first third of the 20th century and, recognizing the growing importance of the brand, renamed itself "Adox Fotowerke

pos: Crookes tube charge of an atom's nucleus, a process called bremsstrahlung, or they knock an atom's inner electrons into a higher energy level, and these in turn emit X-rays as they return to their former energy level, a process called X-ray fluorescence. Many early Crookes tubes undoubtedly generated X-rays, because early researchers such as Ivan Pulyui had noticed that they could make foggy marks on nearby unexposed photographic plates. On November 8, 1895, Wilhelm Röntgen was operating a Crookes tube covered with black cardboard when he noticed that a nearby fluorescent screen glowed faintly. He realized that some unknown invisible rays from

pos: X-ray generator or oil recirculating systems. In medical imaging applications, an x-ray machine has a control console that is used by a radiologic technologist to select x-ray attributes suitable for the specific exam, a power supply that creates and produces the desired kVp (peak kilovoltage), mA (milliamperes, sometimes referred to as mAs which is actually mA multiplied by the desired exposure length) for the x-ray tube, and the x-ray tube itself. The discovery of X-rays came from experimenting with Crookes tubes, an early experimental electrical discharge tube invented by English physicist William Crookes around 1869-1875. In 1895, Wilhelm Röntgen discovered X-rays emanating

pos: Electromagnetic radiation waves, and produced and characterized what were later termed radio waves and microwaves. Wilhelm Röntgen discovered and named X-rays. After experimenting with high voltages applied to an evacuated tube on 8 November 1895, he noticed a fluorescence on a nearby plate of coated glass. In one month, he discovered X-rays' main properties. The last portion of the EM spectrum to be discovered was associated with radioactivity. Henri Becquerel found that uranium salts caused fogging of an unexposed photographic plate through a covering paper in a manner similar to X-rays, and Marie Curie discovered that only certain elements gave off these

pos: Mutagen the discovery of X-ray by Wilhelm Röntgen and radioactivity by Henri Becquerel. Georgii Nadson and German Filippov were the first who created fungi mutants under ionizing radiation in 1925. The mutagenic property of mutagens was first demonstrated in 1927, when Hermann Muller discovered that x-rays can cause genetic mutations in fruit flies, producing phenotypic mutants as well as observable changes to the chromosomes, visible due to presence of enlarged 'polytene' chromosomes in fruit fly salivary glands. His collaborator Edgar Altenburg also demonstrated the mutational effect of UV radiation in 1928. Muller went on to use x-rays to create Drosophila mutants

neg: Sterling Newberry the specimen very close to a point source of X-rays and then farther back a photographic plate. The "shadow" of the specimen would be under-exposed, that is X-ray dark, on the plate. This process is similar to medical X-rays, except that the microscope uses a point source for clarity whereas a medical x-ray tends to use a much larger x-ray source to avoid distortion. Sterling Newberry Sterling Price Newberry (August 10, 1915 – January 28, 2017) was an American inventor and microscopist. He was born in Springfield, Missouri. Newberry invented the shadow X-ray microscope and was one of the founders

neg: Josef Maria Eder the "mercury oxalate photometer" which was a chemical photometer to measure the intensity of UV radiation. After the effect of X-rays on photographic material was published, Eder did research to improve the sensitivity of photographic material to X-rays. By 1884, Eder started writing his "Extensive Handbook of Photography", which is still available as reprint. He was awarded the Lieben Prize in 1895 and became a member of the Austrian Academy of Sciences in 1930. Eder founded the Institute for Photography and Reproduction Techniques (today the ). In 1884 he was awarded the Progress Medal of the Photographic Society of Great

neg: William Herbert Rollins rheostat that he invented which was continuously variable, depending on the effect of light on the electrical conductivity of selenium. John Trowbridge, Professor of Physics at Harvard University, wrote, "No one appears to have had the experience of Dr. Rollins in exhausting X-ray tubes to the point of greatest efficiency". Rollins was one of the earliest pioneers to understand the possible dangers of X-rays. Rollins suggested in 1901 that anyone working with X-rays should wear leaded glasses, enclose the X-ray tube in a leaded box and to cover all areas of the body not being radiographed with a radiopaque shield.

neg: Stereoautograph Stereoautograph The Stereoautograph is a complex opto-mechanical measurement instrument for the evaluation of analog or digital photograms. It is based on the stereoscopy effect by using two aero photos or two photograms of the topography or of buildings from different standpoints. It was invented by Eduard von Orel in 1907. The photograms or photographic plates are oriented by measured passpoints in the field or on the building. This procedure can be carried out digitally (by methods of triangulation and projective geometry or iteratively (repeated angle corrections by congruent rays). The accuracy of modern autographs is about 0.001 mm. Well known

neg: X-ray vary in shape and function depending on their purpose. Imaging detectors such as those used for radiography were originally based on photographic plates and later photographic film, but are now mostly replaced by various digital detector types such as image plates and flat panel detectors. For radiation protection direct exposure hazard is often evaluated using ionization chambers, while dosimeters are used to measure the radiation dose a person has been exposed to. X-ray spectra can be measured either by energy dispersive or wavelength dispersive spectrometers. Since Röntgen's discovery that X-rays can identify bone structures, X-rays have been used for medical

neg: John F. Kennedy autopsy A sufficient number of unique anatomic characteristics were present in X-rays taken before and after the President's death to conclude that the autopsy X-rays were of President Kennedy. This conclusion was consistent with the findings of a forensic dentist employed by the committee. Since many of the X-rays taken during the course of the autopsy included Kennedy's teeth, it was possible to determine, using his dental records, that the X-rays were of the President. As soon as the forensic dentist and anthropologists had determined that the autopsy photographs and X-rays were of the President, photographic scientists and radiologists examined the

neg: Characteristic X-ray is called the Auger effect. Characteristic X-rays can be used to identify the particular element from which they are emitted. This property is used in various techniques, including X-ray fluorescence spectroscopy, particle-induced X-ray emission, energy-dispersive X-ray spectroscopy, and wavelength-dispersive X-ray spectroscopy. Characteristic X-ray Characteristic X-rays are emitted when outer-shell electrons fill a vacancy in the inner shell of an atom, releasing X-rays in a pattern that is "characteristic" to each element. Characteristic X-rays were discovered by Charles Glover Barkla in 1909, who later won the Nobel Prize in Physics for his discovery in 1917. Characteristic X-rays are produced when an

neg: Radiography Radiography Radiography is an imaging technique using X-rays, gamma rays, or similar radiation to view the internal form of an object. To create the image, a beam of X-rays or other form of electromagnetic radiation is produced by an X-ray generator and is projected toward the object. A certain amount of the X-rays or other radiation is absorbed by the object, dependent on the object's density and structural composition. The X-rays that pass through the object are captured behind the object by a detector (either photographic film or a digital detector). The generation of flat two dimensional images by this

neg: Lawrence Bragg father argued that X-rays are streams of particles, others argued that they are waves. Max von Laue directed an X-ray beam at a crystal in front of a photographic plate; alongside of the spot where the beam struck there were additional spots from deflected rays hence X-rays are waves. In 1912, as a first-year research student at Cambridge, W L Bragg, while strolling by the river, had the insight that crystals made from parallel sheets of atoms would not diffract X-ray beams that struck their surface at most angles because X-rays deflected by collisions with atoms would be out of

neg: X-ray medical use when he made a picture of his wife's hand on a photographic plate formed due to X-rays. The photograph of his wife's hand was the first photograph of a human body part using X-rays. When she saw the picture, she said "I have seen my death." The discovery of X-rays stimulated a veritable sensation. Röntgen's biographer Otto Glasser estimated that, in 1896 alone, as many as 49 essays and 1044 articles about the new rays were published. This was probably a conservative estimate, if one considers that nearly every paper around the world extensively reported about the new

neg: Bucky-Potter grid Bucky-Potter grid The Bucky-Potter grid is a device invented by German radiologist Gustav Bucky and improved by American radiologist Hollis E. Potter that enhances the quality of diagnostic medical x-ray images. The grid is positioned on the opposite side of the patient from the x-ray tube to reduce the quantity of scattered x-rays that reach the X-ray detector. Reducing the amount of scattered x-rays increases the image’s contrast resolution and, consequently, the visibility of soft tissues. Scattered x-rays do not travel in parallel to rays that pass directly through the patient. The quantity of scattering depends on several factors including:

neg: Ionizing radiation defined as being between about 120 eV and 120 keV, and gamma rays as being of any energy above 100 to 120 keV, regardless of source. Most astronomical "gamma-ray astronomy" are known "not" to originate in nuclear radioactive processes but, rather, result from processes like those that produce astronomical X-rays, except driven by much more energetic electrons. Photoelectric absorption is the dominant mechanism in organic materials for photon energies below 100 keV, typical of classical X-ray tube originated X-rays. At energies beyond 100 keV, photons ionize matter increasingly through the Compton effect, and then indirectly through pair production at energies

neg: Rope trick effect causes the effect. Because of the lack of guy wires, no "rope trick" effects were observed in surface-detonation tests, free-flying weapons tests, or underground tests. The cause of a surface mottling is more complex. In the initial microseconds after the explosion, a fireball is formed around the bomb by the massive numbers of thermal x-rays released by the explosion process. These x-rays cannot travel very far in the lower atmosphere before reacting with molecules in the air, so the result is a fireball that rapidly forms within about in diameter and does not expand. This is known as a "radiatively

neg: Gray (unit) roentgen in honour of Röntgen, who had died five years previously. At the 1937 meeting of the ICRU, this definition was extended to apply to gamma radiation as well as X-rays. This approach, although appropriate for the technology of the day, had the disadvantage of not being a direct measure of either the intensity of X-rays or their absorption in target material, but rather a measurement of the effect of the X-rays in a specific circumstance; the ionisation of dry air. In 1940, Louis Harold Gray, who had been studying the effect of neutron damage on human tissue, together with

neg: Speed bump municipalities, but Chatham is the first place to put it in practice". The average automobile's top speed at the time was around . Arthur Holly Compton was a physicist and winner of the Nobel Prize in physics in 1927 for his discoveries resulting in major changes in electromagnetic theory. He is commonly known for his work on the Compton Effect with X-rays. He also invented what he called "traffic control bumps," the basic design for the speed hump, in 1953. Compton began designs on the speed bump after noticing the speed at which motorists passed Brookings Hall at Washington University

neg: Henry Snowden Ward politician. After returning to England they lived for many years at Golden Green, Hadlow, Kent. He and his wife, an accomplished photographer, edited in London "The Photogram" (1894–1905), continued from 1906 as "The Photographic Monthly"; "The Process Photogram" (1895–1905), continued from 1906 as "The Process Engravers' Monthly"; also "Photograms of the Year" (from 1896) and "The Photographic Annual" (from 1908). He also compiled many technical handbooks, of which the chief were "Practical Radiography", the first handbook in English on X-rays, then known as Röntgen rays (with A. W. Isenthal, 1896; new editions in 1897, 1898, and 1901); "The Figures, Facts,

neg: X-ray "X-radiation" to signify an unknown type of radiation. Spelling of "X-ray(s)" in the English language includes the variants "x-ray(s)", "xray(s)", and "X ray(s)". Before their discovery in 1895 X-rays were just a type of unidentified radiation emanating from experimental discharge tubes. They were noticed by scientists investigating cathode rays produced by such tubes, which are energetic electron beams that were first observed in 1869. Many of the early Crookes tubes (invented around 1875) undoubtedly radiated X-rays, because early researchers noticed effects that were attributable to them, as detailed below. Crookes tubes created free electrons by ionization of the residual air

neg: X-ray were actually X-rays. In 1889 Ukrainian-born Ivan Pulyui, a lecturer in experimental physics at the Prague Polytechnic who since 1877 had been constructing various designs of gas-filled tubes to investigate their properties, published a paper on how sealed photographic plates became dark when exposed to the emanations from the tubes. Hermann von Helmholtz formulated mathematical equations for X-rays. He postulated a dispersion theory before Röntgen made his discovery and announcement. It was formed on the basis of the electromagnetic theory of light. However, he did not work with actual X-rays. In 1894 Nikola Tesla noticed damaged film in his lab

neg: John F. Kennedy autopsy autopsy materials. Neither the Clark Panel nor the Rockefeller Commission undertook to determine if the X-rays and photographs were, in fact, authentic. Considering the numerous issues that arisen over the years with respect to autopsy X-rays and photographs, the committee believed that authentication was a crucial step in the investigation. The authentication of the autopsy X-rays and photographs was accomplished by the committee assisting its photographic evidence panel as well as forensic dentists, forensic anthropologists, and radiologists working for the committee. Two questions were put to these experts: To determine if the photographs of the autopsy subject were actually of

neg: Photographic film and a source of X-rays, without a lens, as if a translucent object were imaged by being placed between a light source and standard film. Unlike other types of film, X-ray film has a sensitive emulsion on both sides of the carrier material. This reduces the X-ray exposure for an acceptable image – a desirable feature in medical radiography. The film is usually placed in contact with a thin layer of lead which also enhances its sensitivity. Film optimized for sensing X-rays and for gamma rays is sometimes used for radiation dosimetry and personal monitoring. Film has a number of

neg: Inertial confinement fusion D-T fuel suspended in the center of a metal shell, today known as a hohlraum. The shell provided the same effect as the bomb casing in an H-bomb, trapping x-rays inside so they irradiated the fuel. The main difference is that the x-rays would not be supplied by a primary within the shell, but some sort of external device that heated the shell from the outside until it was glowing in the x-ray region (see thermal radiation). The power would be delivered by a then-unidentified pulsed power source he referred to using bomb terminology, the "primary". The main advantage to

neg: X-ray detector film allows a lower dose to the patient, because the screen(s) improve the efficiency of x-ray detection, making more activation of the film from the same amount of x-rays, or the same activation of the film from a smaller amount of x-rays. Phosphor plate radiography is a method of recording X-rays using photostimulated luminescence (PSL), pioneered by Fuji in the 1980s. A photostimulable phosphor plate (PSP) is used in place of the photographic plate. After the plate is X-rayed, excited electrons in the phosphor material remain 'trapped' in 'colour centres' in the crystal lattice until stimulated by a laser beam

neg: Mihran Kassabian X-ray laboratory at Philadelphia General had recently made the second-ever X-ray diagnosis of a brain tumor. Combining his interests in electrotherapy, photography and the use of X-rays, Kassabian was able to establish radiology as a clinical entity worthy of its own department. He served as a delegate of the American Medical Association at international conferences, and he was a vice president of the American Roentgen Ray Society (ARRS). Kassabian invented a positioning device for chest X-rays that showed the body's rotundity; previously, X-ray images had rendered the ribs as flat. He wrote a textbook, "Electro-therapeutics and Roentgen Rays", which was

neg: Fernand Holweck gaining his doctorate in 1922, and eventually becoming Director of Research at the CNRS (the French National Centre for Scientific Research) in 1938. In his doctoral thesis, Holweck described a seminal study of soft X-rays, that part of the spectrum of electromagnetic radiation which lies in between X-rays and the far ultraviolet. To facilitate his experimental studies, he invented a new type of vacuum pump, which later became known as the Holweck pump. This pump, which utilised the drag of air molecules against a rotating surface, achieved vacuums as great as one millionth of a centimetre of mercury, was subsequently

neg: Spectral line manner, resulting under some conditions even in a collisional "narrowing", known as the Dicke effect. For each element, the following table shows the spectral lines which show up in the visible spectrum, from about 400nm-700nm. Without qualification, "spectral lines" generally implies that one is talking about lines with wavelengths which fall into the range of the visible spectrum. However, there are also many spectral lines which show up at wavelengths outside this range. At the much shorter wavelengths of x-rays, these are known as characteristic X-rays. Other frequencies have atomic spectral lines as well, such as the Lyman series, which

neg: X-ray vision effect might be created via x-rays is unexplained (the x-rays from the viewer's eyes would need to bounce back to his eyes the same way as normal light reflects off objects and into the viewer's eyes: x-rays simply pass through an object and continue on their way. X-ray films are made as x-rays pass through an object and then through the x-ray film. The images seen on x-ray film are "shadows" of the objects the x-rays passed through on their way to the film). As depicted, x-ray vision is actually more of a form of the supposed psychic ability of

neg: Project Excalibur and turning some small amount of that into a beam travelling out the end. One can consider the effect as increasing the brightness of the X-rays falling on the target compared to the X-rays released by the bomb itself. The enhancement of the brightness compared to the unfocused output from the bomb is formula_1, where formula_2 is the efficiency of conversion from bomb X-rays to laser X-rays, and formula_3 is the dispersion angle. If a typical ICBM is in diameter, at a distance of that represents a solid angle of 10 steradian (sr). Estimates of the dispersion angles from the

neg: X-ray detector can provide very high resolution measurements, for dosimetry and profiling purposes, particularly in radiotherapy physics. X-ray detector X-ray detectors are devices used to measure the flux, spatial distribution, spectrum, and/or other properties of X-rays. Detectors can be divided into two major categories: imaging detectors (such as photographic plates and X-ray film (photographic film), now mostly replaced by various digitizing devices like image plates or flat panel detectors) and dose measurement devices (such as ionization chambers, Geiger counters, and dosimeters used to measure the local radiation exposure, dose, and/or dose rate, for example, for verifying that radiation protection equipment and procedures

neg: X-ray detector X-ray detector X-ray detectors are devices used to measure the flux, spatial distribution, spectrum, and/or other properties of X-rays. Detectors can be divided into two major categories: imaging detectors (such as photographic plates and X-ray film (photographic film), now mostly replaced by various digitizing devices like image plates or flat panel detectors) and dose measurement devices (such as ionization chambers, Geiger counters, and dosimeters used to measure the local radiation exposure, dose, and/or dose rate, for example, for verifying that radiation protection equipment and procedures are effective on an ongoing basis). To obtain an image with any type of image

neg: Radiographer screen, about 1 metre away. Röntgen realized some invisible rays coming from the tube were passing through the cardboard to make the screen glow: they were passing through an opaque object to affect the film behind it. Röntgen discovered X-rays' medical use when he made a picture of his wife's hand on a photographic plate formed due to X-rays. The photograph of his wife's hand was the first ever photograph of a human body part using X-rays. When she saw the picture, she said, "I have seen my death." The first use of X-rays under clinical conditions was by John

neg: Osteopenia mineral density. It is also a sign of normal aging, in contrast to osteoporosis which is present in pathologic aging. Osteopenia is also a common effect of coeliac disease, even among patients who are otherwise asymptomatic. Scans of bones anywhere in the body can be done with X-rays, known as DEXA (dual X-ray absorptiometry). Scans can also be done with portable scanners using ultrasound, and portable X-ray machines can measure density in the heel. A study paid for by Merck found that the extent to which osteopenia was diagnosed varied from 28 to 45 percent, depending on the type of

neg: John F. Kennedy autopsy original autopsy photographs, negatives, transparencies, and X-rays for signs of alteration. They concluded that there was no evidence of the photographic or radiographic materials having been altered, so the committee determined that the autopsy X-rays and photographs were a valid basis for the conclusions of the committee's forensic pathology panel. While the examination of the autopsy X-rays and photographs was mainly based on its analysis, the forensic pathology panel also had access to all relevant witness testimony. Furthermore, all tests and evidence analyses requested by the panel were performed. It was only after considering all of this evidence that the

neg: X-ray generator tissues such as bones and teeth. This is because bones absorb the radiation more than the less dense soft tissue. X-rays from a source pass through the body and onto a photographic cassette. Areas where radiation is absorbed show up as lighter shades of grey (closer to white). This can be used to diagnose broken or fractured bones. In fluoroscopy, imaging of the digestive tract is done with the help of a radiocontrast agent such as barium sulfate, which is opaque to X-rays. X-ray machines are used to screen objects non-invasively. Luggage at airports and student baggage at some schools

neg: Nuclear technology resolution, short time span imaging in applications known as Positron emission tomography. Radiation is also used to treat diseases in radiation therapy. Since some ionizing radiation can penetrate matter, they are used for a variety of measuring methods. X-rays and gamma rays are used in industrial radiography to make images of the inside of solid products, as a means of nondestructive testing and inspection. The piece to be radiographed is placed between the source and a photographic film in a cassette. After a certain exposure time, the film is developed and it shows any internal defects of the material. Gauges

neg: Radiography a picture of his wife's hand on a photographic plate formed due to X-rays. The photograph of his wife's hand was the first ever photograph of a human body part using X-rays. When she saw the picture, she said, "I have seen my death." The first use of X-rays under clinical conditions was by John Hall-Edwards in Birmingham, England on 11 January 1896, when he radiographed a needle stuck in the hand of an associate. On 14 February 1896, Hall-Edwards also became the first to use X-rays in a surgical operation. The United States saw its first medical X-ray obtained

neg: Crookes tube window caused it to fluoresce, even though no light reached it. A photographic plate held up to it would be darkened, even though it was not exposed to light. The effect had a very short range of about . He measured the ability of cathode rays to penetrate sheets of material, and found they could penetrate much farther than moving atoms could. Since atoms were the smallest particles known at the time, this was first taken as evidence that cathode rays were waves. Later it was realized that electrons were much smaller than atoms, accounting for their greater penetration ability.

neg: Phase problem If the phases are known, the electron density can be simply obtained by Fourier synthesis. This Fourier transform relation also holds for two-dimensional far-field diffraction patterns (also called Fraunhofer diffraction) giving rise to a similar type of phase problem. In X-ray crystallography, there are several ways to recover the lost phases. A powerful solution is the "Multi-wavelength Anomalous Diffraction" (MAD) method. In this technique, atoms' inner electrons absorb X-rays of particular wavelengths, and reemit the X-rays after a delay, inducing a phase shift in all of the reflections, known as the "anomalous dispersion effect". Analysis of this phase shift (which

neg: Electromagnetic spectrum not blocked well by the atmosphere, but does not cause sunburn and does less biological damage. However, it is not harmless and does create oxygen radicals, mutations and skin damage. See ultraviolet for more information. After UV come X-rays, which, like the upper ranges of UV are also ionizing. However, due to their higher energies, X-rays can also interact with matter by means of the Compton effect. Hard X-rays have shorter wavelengths than soft X-rays and as they can pass through many substances with little absorption, they can be used to 'see through' objects with 'thicknesses' less than that equivalent

neg: Frank Styant Browne artistic and photographic circles, including: Frank Styant-Browne, Artist (Photographer), Artist (Painter), also known as F. Styant Browne, Frank Styant Browne, F. S. B. Frank Styant Browne Frank Styant Browne (10 July 1854 – 17 April 1938), also known as Styant Browne, was an Australian pharmacist, artist, photographer and X-ray pioneer from Tasmania. In Australia, the medical men of the day took a slow approach in the adoption of the new science that involved X-rays. Many of the early demonstrations were made by investigators outside the medical field. Upon examination of the initial investigators, several key factors were common. The individuals

neg: Spectrometer Telescope for Imaging X-rays developed by an international collaboration led by the University of Applied Sciences and Arts Northwestern Switzerland. Spectrometer Telescope for Imaging X-rays The Spectrometer Telescope for Imaging X-rays (STIX) is one of the 10 instruments that are part of the scientific payload for the ESA Solar Orbiter mission, to be launched in 2020. The STIX instrument is an X-ray imaging spectrometer, whose purpose is to study the extremely hot solar plasma and the high-energy electrons accelerated during a solar flare. It can detect X-rays from 4 to 150 keV and exploits an indirect imaging technique based on the moiré effect, to

neg: Spectrometer Telescope for Imaging X-rays Spectrometer Telescope for Imaging X-rays The Spectrometer Telescope for Imaging X-rays (STIX) is one of the 10 instruments that are part of the scientific payload for the ESA Solar Orbiter mission, to be launched in 2020. The STIX instrument is an X-ray imaging spectrometer, whose purpose is to study the extremely hot solar plasma and the high-energy electrons accelerated during a solar flare. It can detect X-rays from 4 to 150 keV and exploits an indirect imaging technique based on the moiré effect, to produce images with few arcsec angular resolution in any given energy range. The instrument has been

neg: X-ray photoelectron spectroscopy X-ray is roughly 0.70 eV, which, in effect is the ultimate energy resolution of a system using non-monochromatic X-rays. Non-monochromatic X-ray sources do not use any crystals to diffract the X-rays which allows all primary X-rays lines and the full range of high-energy Bremsstrahlung X-rays (1–12 keV) to reach the surface. The ultimate energy resolution (FWHM) when using a non-monochromatic Mg "K"-alpha source is 0.9–1.0 eV, which includes some contribution from spectrometer-induced broadening. XPS is routinely used to determine: The ability to produce chemical state information (as distinguished from merely elemental information) from the topmost few nm of any surface

neg: Alexander de Cadenet series of photographic "skull portraits", based on x-rays of his subjects' skulls. The ongoing series of works explores the themes of human achievement and the sacredness of art in particular within the tradition of Vanitas. The first "Celebrities Series" was launched in 1999 at 30 Underwood Street Gallery in Shoreditch, London. This launched de Cadenet’s skull portraits concept, which he has described as ‘drawing on an everyday language and experience to communicate a deeper message”. The artist has been sourcing the skull x-rays of significant subjects from history who are no longer living for incorporation into skull portraits. As of

neg: Frederick Woodward Branson of traversing can be seen upon the screen; or, by substituting a sensitive plate for the screen, the effect may be photographed. The "X-ray meter," as the quadrant is called, thus furnishes an easy means of comparing the intensity of Rontgen ray emitted by different tubes and by the same tubes at different times." In a memoir of Wilhelm Conrad Röntgen by Otto Glasser, 1933, Branson's invention of a qualimeter is noticed. Glasser referred to the work of Röntgen and the attempt to measure the photographic quality of the Röntgen rays: "Röntgen had studied carefully the penetration of the roentgen

neg: Scotch Tape familiar green and yellow tartan branding. In 1953, Soviet scientists showed that triboluminescence caused by peeling a roll of an unidentified Scotch brand tape in a vacuum can produce X-rays. In 2008, American scientists performed an experiment that showed the rays can be strong enough to leave an X-ray image of a finger on photographic paper. Scotch Tape Scotch Tape is a brand name used for pressure-sensitive tapes manufactured by 3M as part of the company's Scotch brand. Their magnetic recording tape products were also sold under the Scotch brand. The precursor to the current tapes was developed in the

neg: Radiation a month, he discovered the main properties of X-rays that we understand to this day. In 1896, Henri Becquerel found that rays emanating from certain minerals penetrated black paper and caused fogging of an unexposed photographic plate. His doctoral student Marie Curie discovered that only certain chemical elements gave off these rays of energy. She named this behavior radioactivity. Alpha rays (alpha particles) and beta rays (beta particles) were differentiated by Ernest Rutherford through simple experimentation in 1899. Rutherford used a generic pitchblende radioactive source and determined that the rays produced by the source had differing penetrations in materials. One

neg: Mössbauer effect or absorbing end of a gamma transition: emission and absorption occur at the same energy, resulting in strong, resonant absorption. The emission and absorption of X-rays by gases had been observed previously, and it was expected that a similar phenomenon would be found for gamma rays, which are created by nuclear transitions (as opposed to X-rays, which are typically produced by electronic transitions). However, attempts to observe nuclear resonance produced by gamma-rays in gases failed due to energy being lost to recoil, preventing resonance (the Doppler effect also broadens the gamma-ray spectrum). Mössbauer was able to observe resonance in nuclei

neg: Heel effect Heel effect In X-ray tubes, the heel effect, or, more precisely, the anode heel effect is a variation of the intensity of X-rays emitted by the anode depending on the direction of emission along the anode-cathode axis. Due to the geometry of the anode, X-rays emitted towards the cathode are in general more intense than those emitted perpendicular to the cathode–anode axis. The effect stems from the absorption of X-ray photons before they leave the anode in which they are produced. The probability of absorption depends on the distance the photons travel within the anode material, which in turn depends

neg: Rotational modulation collimator RMCs. A more recent satellite that used RMCs was RHESSI. Rotational modulation collimator Rotational modulation collimators (or RMCs) are a specialization of the modulation collimator, an imaging device invented by Minoru Oda. Devices of this type create images of high energy X-rays (or other radiations that cast shadows). Since high energy X-rays are not easily focused, such optics have found applications in various instruments. RMCs selectively block and unblock X-rays in a way which depends on their incoming direction, converting image information into time variations. Various mathematical transformations can then reconstitute the image of the source. The Small Astronomy Satellite

neg: Rotational modulation collimator Rotational modulation collimator Rotational modulation collimators (or RMCs) are a specialization of the modulation collimator, an imaging device invented by Minoru Oda. Devices of this type create images of high energy X-rays (or other radiations that cast shadows). Since high energy X-rays are not easily focused, such optics have found applications in various instruments. RMCs selectively block and unblock X-rays in a way which depends on their incoming direction, converting image information into time variations. Various mathematical transformations can then reconstitute the image of the source. The Small Astronomy Satellite 3, launched in 1975, was one orbiting experiment that used

neg: Robert W. Wood Park, New York. He wrote many articles on spectroscopy, phosphorescence and diffraction. He is best known for his work in ultraviolet light. Another of his claims to fame was his debunking of N-rays in 1904. The French physicist Prosper-René Blondlot claimed to have discovered a new form of radiation similar to X-rays, which he named N-rays. Some physicists reported having successfully reproduced his experiments; others reported that they had failed. Visiting Blondlot's laboratory at the behest of the journal "Nature", Wood surreptitiously removed an essential prism from Blondlot's apparatus during a demonstration. The effect did not vanish, showing that N-rays

neg: X-ray detector most radiation was detected. Further developing steps stabilise the sensitised grains and remove unsensitised grains to prevent further exposure (e.g. from visible light). The first radiographs (X-ray images) were made by the action of X-rays on sensitized glass photographic plates. X-ray film (photographic film) soon replaced the glass plates, and film has been used for decades to acquire (and display) medical and industrial images. Gradually, digital computers gained the ability to store and display enough data to make digital imaging possible. Since the 1990s, computerized radiography and digital radiography have been replacing photographic film in medical and dental applications, though

neg: Heinrich Hertz as aluminium). Philipp Lenard, a student of Heinrich Hertz, further researched this "ray effect". He developed a version of the cathode tube and studied the penetration by X-rays of various materials. Philipp Lenard, though, did not realize that he was producing X-rays. Hermann von Helmholtz formulated mathematical equations for X-rays. He postulated a dispersion theory before Röntgen made his discovery and announcement. It was formed on the basis of the electromagnetic theory of light ("Wiedmann's Annalen", Vol. XLVIII). However, he did not work with actual X-rays. Heinrich Hertz was a Lutheran throughout his life and would not have considered himself

neg: Strain scanning moving neutrons - time of flight: The details of the technique are heavily influenced by the type of radiation used since lab X-rays, synchrotron X-rays and neutrons have very different properties. Nevertheless, there is considerable overlap between the various methods. Strain scanning In physics, strain scanning is the general name for various techniques that aim to measure the strain in a crystalline material through its effect on the diffraction of X-rays and neutrons. In these methods the material itself is used as a form of strain gauge. The various methods are derived from powder diffraction but look for the small

neg: X-ray detector film technology remains in widespread use in industrial radiography processes (e.g. to inspect welded seams). The metal silver (formerly necessary to the radiographic & photographic industries) is a non-renewable resource although silver can easily be reclaimed from spent X-ray film. Where X-ray films required wet processing facilities, newer digital technologies do not. Digital archiving of images also saves physical storage space. Because photographic plates are sensitive to X-rays, they provide a means of recording the image, but they also require much X-ray exposure (to the patient). The addition of a fluorescent intensifying screen (or screens) in close contact with the

neg: X-ray for this discovery. In 1912, Max von Laue, Paul Knipping, and Walter Friedrich first observed the diffraction of X-rays by crystals. This discovery, along with the early work of Paul Peter Ewald, William Henry Bragg, and William Lawrence Bragg, gave birth to the field of X-ray crystallography. The Coolidge X-ray tube was invented during the following year by William D. Coolidge. It made possible the continuous emissions of X-rays. X-ray tubes similar to this are still in use in 2012. The use of X-rays for medical purposes (which developed into the field of radiation therapy) was pioneered by Major John

neg: Radiography between the patient and the detector to reduce the quantity of scattered x-rays that reach the detector. This improves the contrast resolution of the image, but also increases radiation exposure for the patient. Detectors can be divided into two major categories: imaging detectors (such as photographic plates and X-ray film (photographic film), now mostly replaced by various digitizing devices like image plates or flat panel detectors) and dose measurement devices (such as ionization chambers, Geiger counters, and dosimeters used to measure the local radiation exposure, dose, and/or dose rate, for example, for verifying that radiation protection equipment and procedures are

neg: Projectional radiography A Bucky-Potter grid may be placed between the patient and the detector to reduce the quantity of scattered x-rays that reach the detector. This improves the contrast resolution of the image, but also increases radiation exposure for the patient. Detectors can be divided into two major categories: imaging detectors (such as photographic plates and X-ray film (photographic film), now mostly replaced by various digitizing devices like image plates or flat panel detectors) and dose measurement devices (such as ionization chambers, Geiger counters, and dosimeters used to measure the local radiation exposure, dose, and/or dose rate, for example, for verifying that

neg: Duane–Hunt law Duane–Hunt law The Duane–Hunt law, named after the American physicists William Duane and Franklin Hunt, gives the maximum frequency of X-rays that can be emitted by Bremsstrahlung in an X-ray tube by accelerating electrons through an excitation voltage "V" into a metal target. The maximum frequency "ν" is given by which corresponds to a minimum wavelength where "h" is Planck's constant, "e" is the charge of the electron, and "c" is the speed of light. This can also be written as: The process of X-ray emission by incoming electrons is also known as the inverse photoelectric effect. In an X-ray

neg: Heel effect ankle end than the toes, the toes should be positioned towards the anode and the ankle towards the cathode. There have also been some efforts to eliminate the heel effect through automatic software adjustment of pixel values. Heel effect In X-ray tubes, the heel effect, or, more precisely, the anode heel effect is a variation of the intensity of X-rays emitted by the anode depending on the direction of emission along the anode-cathode axis. Due to the geometry of the anode, X-rays emitted towards the cathode are in general more intense than those emitted perpendicular to the cathode–anode axis. The

neg: X-ray crystallography English Garden in Munich. Ewald had proposed a resonator model of crystals for his thesis, but this model could not be validated using visible light, since the wavelength was much larger than the spacing between the resonators. Von Laue realized that electromagnetic radiation of a shorter wavelength was needed to observe such small spacings, and suggested that X-rays might have a wavelength comparable to the unit-cell spacing in crystals. Von Laue worked with two technicians, Walter Friedrich and his assistant Paul Knipping, to shine a beam of X-rays through a copper sulfate crystal and record its diffraction on a photographic

neg: Auger effect either X-rays or energetic electrons and measures the intensity of Auger electrons that result as a function of the Auger electron energy. The resulting spectra can be used to determine the identity of the emitting atoms and some information about their environment. Auger recombination is a similar Auger effect which occurs in semiconductors. An electron and electron hole (electron-hole pair) can recombine giving up their energy to an electron in the conduction band, increasing its energy. The reverse effect is known as impact ionization. The Auger effect can impact biological molecules such as DNA. Following the K-shell ionization of the

neg: Roentgen (unit) either the intensity of X-rays or their absorption, but rather was a measurement of the ionising effect of X-rays in a specific circumstance; which was dry air at 0 °C and 1 standard atmosphere of pressure. Because of this the rontgen had a variable relationship to the amount of energy absorbed dose per unit mass in the target material, as different materials have different absorption characteristics. As the science of radiation dosimetry developed, this was seen as a serious shortcoming. In 1940, Louis Harold Gray, who had been studying the effect of neutron damage on human tissue, together with William

neg: Synchrotron light source strong magnetic fields. This is similar to a radio antenna, but with the difference that the relativistic speed changes the observed frequency due to the Doppler effect by a factor formula_2. Relativistic Lorentz contraction bumps the frequency by another factor of formula_2, thus multiplying the gigahertz frequency of the resonant cavity that accelerates the electrons into the X-ray range. Another dramatic effect of relativity is that the radiation pattern is distorted from the isotropic dipole pattern expected from non-relativistic theory into an extremely forward-pointing cone of radiation. This makes synchrotron radiation sources the most brilliant known sources of X-rays. The

neg: Edward Hope Kirkby They are buried together at Waverley Cemetery. So ended a life of invention largely unrecognised as biographers of George Taylor and Archibald Shaw claimed all the credit for them for Kirkby’s endeavours. Edward Hope Kirkby was a jeweler watchmaker in Williamstown who eventually became a manufacturing electrician making systems of fire protection, in 1908 he invented and patented the first automatic sprinkler alarm. He is first recorded as experimenting with X-ray in September 1896 This is only 9 months after Roentgen presented his discovery of X-rays. He is reported as experimenting with the medical staff at Williamstown Hospital later that

neg: United States House Select Committee on Assassinations the location of the presidential limousine and its occupants combined with the bullet wounds found on the president and governor. A team of photographic experts were used to answer several questions related to the photographic evidence of the case. Forensic anthropologists as well as photographic and radiographic experts, based on unique anatomical details, verified that JFK's autopsy photos and x-rays were only of the late president. Forensic anthropologists were also used to verify that all relevant photographs of Lee Harvey Oswald were of only one person. They verified that the backyard photos (showing Oswald holding the rifle used to kill

neg: X-ray appeared in the San Francisco Examiner. Starting in 1888, Philipp Lenard, a student of Heinrich Hertz, conducted experiments to see whether cathode rays could pass out of the Crookes tube into the air. He built a Crookes tube with a "window" in the end made of thin aluminum, facing the cathode so the cathode rays would strike it (later called a "Lenard tube"). He found that something came through, that would expose photographic plates and cause fluorescence. He measured the penetrating power of these rays through various materials. It has been suggested that at least some of these "Lenard rays"

neg: Lipid bilayer characterization x-rays are relatively insensitive to light elements such as hydrogen. This effect is a consequence of the fact that x-rays interact with matter by scattering off of electron density which decreases with decreasing atomic number. In contrast, neutrons scatter off of nuclear density and nuclear magnetic fields so sensitivity does not decrease monotonically with z. This mechanism also provides strong isotopic contrast in some cases, notably between hydrogen and deuterium, allowing researchers to tune the experimental baseline by mixing water and deuterated water. Using reflectometry rather than scattering with neutrons or x-rays allow experimenters to probe supported bilayers or multilayer

neg: Gamma-ray astronomy Gamma-ray astronomy Gamma-ray astronomy is the astronomical observation of gamma rays, the most energetic form of electromagnetic radiation, with photon energies above 100 keV. Radiation below 100 keV is classified as X-rays and is the subject of X-ray astronomy. In most known cases, gamma rays from solar flare and Earth's atmosphere)are generated in the MeV range, but it is now known that gamma rays in the GeV range can also be generated by solar flares. Formerly, it was believed that gamma rays in the GeV range do not originate in the Solar System. As GeV gamma rays are important in

neg: Henry Jasper Redfern was called upon to use the new technology of x-rays for diagnostic and therapeutic studies. Redfern, a pioneer in the field of x-rays and radiology, accepted the call to serve his fellow wounded soldiers. He became a martyr by performing radiographs and paid the price by losing all of his fingers from the radiation exposure. In 1928, Redfern died of cancer, probably due to his heroic efforts and prolonged exposure to radiation from x-rays. Henry Jasper Redfern Henry Jasper Redfern, FSMC, BOA, (1871–1928), or Jasper Redfern was a British optician, photographer, exhibitor, filmmaker, proprietor of photographic and lantern retail business,

neg: Mihajlo Pupin A New York surgeon, Dr. Bull, sent Pupin a patient to obtain an X-ray image of his left hand prior to an operation to remove lead shot from a shotgun injury. The first attempt at imaging failed because the patient, a well-known lawyer, was "too weak and nervous to be stood still nearly an hour" which is the time it took to get an X-ray photo at the time. In another attempt, the Edison fluorescent screen was placed on a photographic plate and the patient's hand on the screen. X-rays passed through the patients hand and caused the screen to

neg: X-ray image intensifier X-ray image intensifier An x-ray image intensifier (XRII) is an image intensifier that converts x-rays into visible light at higher intensity than mere fluorescent screens do. Such intensifiers are used in x-ray imaging systems (such as fluoroscopes ) to allow low-intensity x-rays to be converted to a conveniently bright visible light output. The device contains a low absorbency/scatter input window, typically aluminum, input fluorescent screen, photocathode, electron optics, output fluorescent screen and output window. These parts are all mounted in a high vacuum environment within glass or more recently, metal/ceramic. By its intensifying effect, It allows the viewer to more

neg: External beam radiotherapy useful X-rays are produced when electrons are accelerated to energies at which either the photoelectric effect predominates (for diagnostic use, since the photoelectric effect offers comparatively excellent contrast with effective atomic number "Z") or Compton scatter and pair production predominate (at energies above approximately 200 keV for the former and 1 MeV for the latter), for therapeutic X-ray beams. Some examples of X-ray energies used in medicine are: Megavoltage X-rays are by far most common in radiotherapy for treatment of a wide range of cancers. Superficial and orthovoltage X-rays have application for the treatment of cancers at or close to

neg: Henry Moseley in the external X-ray shielding. These are next diffracted by a standardized salt crystal, with angular results read out as photographic lines by the exposure of an X-ray film fixed at the outside the vacuum tube at a known distance. Application of Bragg's law (after some initial guesswork of the mean distances between atoms in the metallic crystal, based on its density) next allowed the wavelength of the emitted -rays to be calculated. Moseley participated in the design and development of early X-ray spectrometry equipment, learning some techniques from William Henry Bragg and William Lawrence Bragg at the University of

neg: X-ray tube the waveform of the electrical source power (direct or pulsating). The heat produced in these devices is (in Joule) : In radiography voltage is usually expressed in formula_2 (thousands of volts peak), the effective current in mA and the time in seconds: w being the waveform ratio. With a full-wave rectification of a sine wave it equals formula_4, thus the practical unit: Historically, X-rays were discovered radiating from experimental discharge tubes called Crookes tubes invented by British physicist William Crookes and others. As the medical and other uses of X-rays became apparent, workshops began to manufacture specialized Crookes tubes to

neg: Compton scattering is of prime importance to radiobiology, as it is the most probable interaction of gamma rays and high energy X-rays with atoms in living beings and is applied in radiation therapy. In material physics, Compton scattering can be used to probe the wave function of the electrons in matter in the momentum representation. Compton scattering is an important effect in gamma spectroscopy which gives rise to the Compton edge, as it is possible for the gamma rays to scatter out of the detectors used. Compton suppression is used to detect stray scatter gamma rays to counteract this effect. Magnetic Compton

neg: X-ray if the intensity of the X-ray beam is high enough. The beamline from the wiggler at the ID11 at the European Synchrotron Radiation Facility is one example of such high intensity. The measure of X-rays ionizing ability is called the exposure: However, the effect of ionizing radiation on matter (especially living tissue) is more closely related to the amount of energy deposited into them rather than the charge generated. This measure of energy absorbed is called the absorbed dose: The equivalent dose is the measure of the biological effect of radiation on human tissue. For X-rays it is equal to

neg: Neutron bomb that a neutron warhead could successfully cause an unrecoverable glitch by the "transient radiation effects on electronics" (TREE) effects. At very high altitudes, at the edge of the atmosphere and above it, another effect comes into play. At lower altitudes, the x-rays generated by the bomb are absorbed by the air and have mean free paths on the order of meters. But as the air thins out, the x-rays can travel further, eventually outpacing the area of effect of the neutrons. In exoatmospheric explosions, this can be on the order of in radius. In this sort of attack, it is

neg: Grenz rays Grenz rays Grenz rays are part of the electromagnetic spectrum comprising low energy (ultrasoft) X-rays. These were first investigated by Gustav Bucky in 1923 using a cathode vacuum tube with a lithium borate glass window, which he labeled Grenz rays as he believed that the biological effects resembled those of UV light and traditional X-rays and hence were on the border between the two ("Grenz" = border in German). These rays are also known as Bucky rays. Grenz rays are produced by specially calibrated X-ray machines generally operating in the 10 to 30 kV range to produce X-rays with HVL

neg: Radiography Digital devices known as array detectors are becoming more common in fluoroscopy. These devices are made of discrete pixelated detectors known as thin-film transistors (TFT) which can either work "indirectly" by using photo detectors that detect light emitted from a scintillator material such as CsI, or "directly" by capturing the electrons produced when the X-rays hit the detector. Direct detector do not tend to experience the blurring or spreading effect caused by phosphorescent scintillators of or film screens since the detectors are activated directly by X-ray photons. "Dual-energy" radiography is where images are acquired using two separate tube voltages. This

neg: Compton scattering in the "Physical Review" that explained the X-ray shift by attributing particle-like momentum to light quanta (Einstein had proposed light quanta in 1905 in explaining the photo-electric effect, but Compton did not build on Einstein's work). The energy of light quanta depends only on the frequency of the light. In his paper, Compton derived the mathematical relationship between the shift in wavelength and the scattering angle of the X-rays by assuming that each scattered X-ray photon interacted with only one electron. His paper concludes by reporting on experiments which verified his derived relation: The quantity is known as the Compton

neg: Backscatter X-ray vendor (Rapiscan) did not meet their contractual deadline to implement the software. In the European Union, backscatter X-ray screening of airline passengers was banned in 2012 to protect passenger safety, and the deployment at Manchester Airport was removed. Backscatter technology is based on the Compton scattering effect of X-rays, a form of ionizing radiation. Unlike a traditional X-ray machine, which relies on the transmission of X-rays through the object, backscatter X-ray detects the radiation that reflects from the object and forms an image. The backscatter pattern is dependent on the material property and is good for imaging organic material. In

neg: Gamma ray energy of photons produced by nuclear reactions, and thus ultraviolet or lower energy photons produced by these processes would also be defined as "gamma rays". The only naming-convention that is still universally respected is the rule that electromagnetic radiation that is known to be of atomic nuclear origin is "always" referred to as "gamma rays", and never as X-rays. However, in physics and astronomy, the converse convention (that all gamma rays are considered to be of nuclear origin) is frequently violated. In astronomy, higher energy gamma and X-rays are defined by energy, since the processes that produce them may be

neg: Electromagnetic spectrum to a few meters of water. One notable use is diagnostic X-ray imaging in medicine (a process known as radiography). X-rays are useful as probes in high-energy physics. In astronomy, the accretion disks around neutron stars and black holes emit X-rays, enabling studies of these phenomena. X-rays are also emitted by the coronas of stars and are strongly emitted by some types of nebulae. However, X-ray telescopes must be placed outside the Earth's atmosphere to see astronomical X-rays, since the great depth of the atmosphere of Earth is opaque to X-rays (with areal density of 1000 grams per cm), equivalent

neg: Comet Hyakutake the first time a comet had been seen to do so, but astronomers soon found that almost every comet they looked at was emitting X-rays. The emission from Hyakutake was brightest in a crescent shape surrounding the nucleus with the ends of the crescent pointing away from the Sun. The cause of the X-ray emission is thought to be a combination of two mechanisms. Interactions between energetic solar wind particles and cometary material evaporating from the nucleus is likely to contribute significantly to this effect. Reflection of solar X-rays is seen in other Solar System objects such as the Moon,

neg: Superficial X-rays Superficial X-rays Superficial X-rays are low-energy X-rays that do not penetrate very far before they are absorbed. They are produced by X-ray tubes operating at voltages in the 10–100 kV range, and therefore have peak energies in the 10–100 keV range. Precise naming and definitions of energy ranges may vary, and X-rays at the lower end of this range may also be known as Grenz rays. They are useful in radiation therapy for the treatment of various benign or malignant skin problems, including skin cancer and severe eczema. They have a useful depth of up to 5 mm. In some

neg: Sterilization (microbiology) treat multiple pallet loads of low-density packages with very good dose uniformity ratios. X-ray sterilization does not require chemical or radioactive material: high-energy X-rays are generated at high intensity by an X-ray generator that does not require shielding when not in use. X-rays are generated by bombarding a dense material (target) such as tantalum or tungsten with high-energy electrons, in a process known as bremsstrahlung conversion. These systems are energy-inefficient, requiring much more electrical energy than other systems for the same result. Irradiation with X-rays, gamma rays, or electrons does not make materials radioactive, because the energy used is too

neg: Anomalous X-ray scattering in their path, to generate the wanted wavelength of X-rays. This allows scientists to vary the wavelength, which in turn makes it possible to vary the scattering factor for one particular element in the sample under investigation. Thus a particular element can be highlighted. This is known as "contrast variation". In addition to this effect the anomalous scatter is more sensitive to any deviation from sphericity of the electron cloud around the atom. This can lead to resonant effects involving transitions in the outer shell of the atom: resonant anomalous X-ray scattering. Anomalous X-ray scattering Anomalous X-ray scattering AXRS or

neg: Position-effect variegation heterochromatic region has an effect on its expression. The effect is the variegation in a particular phenotype i.e., the appearance of irregular patches of different colour(s), due to the expression of the original wild-type gene in some cells of the tissue but not in others, as seen in the eye of mutated "Drosophila melanogaster." However, it is possible that the effect of the silenced gene is not phenotypically visible in some cases. PEV was observed first in "Drosophila" because it was one of the very first organisms on which X-ray irradiation was used as a mutation inducer. X-rays can cause

neg: Electromagnetic spectrum electrons. In general, nuclear transitions are much more energetic than electronic transitions, so gamma-rays are more energetic than X-rays, but exceptions exist. By analogy to electronic transitions, muonic atom transitions are also said to produce X-rays, even though their energy may exceed , whereas there are many (77 known to be less than ) low-energy nuclear transitions (e.g., the nuclear transition of thorium-229), and, despite being one million-fold less energetic than some muonic X-rays, the emitted photons are still called gamma rays due to their nuclear origin. The convention that EM radiation that is known to come from the nucleus,

neg: X-Rite X-Rite X-Rite, Inc. is a manufacturer of color measurement and management products, located in Grand Rapids, Michigan, United States. The company also creates products that regulate quality in the processing of film and x-rays. The firm was incorporated in 1958 by seven engineers from Lear Siegler. Its first product, x-ray marking tape, was introduced in 1968. In 1975, it introduced its first densitometer for photographic printing use. The firm went public in 1986, and in 1987 moved into a new headquarters and production facility in Grandville, Michigan. By 1990, the firm shifted emphasis to the field of color measurement. In

neg: Cloverleaf quasar a single quasar split into four images, instead of 4 separate quasars. The X-rays from iron atoms were also enhanced relative to X-rays at lower energies. Since the amount of brightening due to gravitational lensing doesn't vary with the wavelength, this means that an additional object has magnified the X-rays. The increased magnification of the X-ray light can be explained by gravitational microlensing, an effect which has been used to search for compact stars and planets in our galaxy. Microlensing occurs when a star or a multiple star system passes in front of light from a background object. If a

neg: Neupert effect accumulated energy injection associated with the acceleration of non-thermal electrons (which produce the hard X-rays via non-thermal bremsstrahlung) release energy in the lower solar atmosphere (the chromosphere); this energy then leads to thermal (soft X-ray) emission as the chromospheric plasma heats and expands into the corona. The effect is very common, but does not represent an exact relationship and is not observed in all solar flares. Neupert effect The Neupert Effect refers to an empirical tendency for high-energy ('hard') X-ray emission to coincide temporally with the rate of rise of lower-energy ('soft') X-ray emission of a solar flare. Here 'hard'

neg: Edward Teller the opinion that the idea to use the x-rays would have eventually occurred to anyone working on the physical processes involved, and that the obvious reason why Teller thought of it right away was because he was already working on the "Greenhouse" tests for the spring of 1951, in which the effect of x-rays from a fission bomb on a mixture of deuterium and tritium was going to be investigated. Whatever the actual components of the so-called Teller–Ulam design and the respective contributions of those who worked on it, after it was proposed it was immediately seen by the scientists

neg: Characteristic X-ray Characteristic X-ray Characteristic X-rays are emitted when outer-shell electrons fill a vacancy in the inner shell of an atom, releasing X-rays in a pattern that is "characteristic" to each element. Characteristic X-rays were discovered by Charles Glover Barkla in 1909, who later won the Nobel Prize in Physics for his discovery in 1917. Characteristic X-rays are produced when an element is bombarded with high-energy particles, which can be photons, electrons or ions (such as protons). When the incident particle strikes a bound electron (the target electron) in an atom, the target electron is ejected from the inner shell of the