X-radiation (composed of X-rays) is a form of electromagnetic radiation Electromagnetic radiation is a phenomenon that takes the form of self-propagating waves in a vacuum or in matter. It comprises electric and magnetic field components, which oscillate in phase perpendicular to each other and perpendicular to the direction of energy propagation. Electromagnetic radiation is classified into several types according to. X-rays have a wavelength In physics, the wavelength of a sinusoidal wave is the spatial period of the wave – the distance over which the wave's shape repeats. It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a characteristic of both traveling waves and in the range of 0.01 to 10 nanometers A nanometre (Ancient Greek: νάνος, nanos, "dwarf"; μέτρον, metrοn, "unit of measurement") is a unit of length in the metric system, equal to one billionth of a metre, corresponding to frequencies Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency. The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency. Loosely speaking, 1 year is the period of the Earth's orbit around the Sun, and the Earth's rotation on its axis has in the range 30 petahertz The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of sine wave, particularly those used in radio and audio applications to 30 exahertz The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of sine wave, particularly those used in radio and audio applications (3 × 1016 Hz to 3 × 1019 Hz) and energies in the range 120 eV In physics, the electron volt is a unit of energy equal to approximately 1.602×10−19 J. By definition, it is equal to the amount of kinetic energy gained by a single unbound electron when it accelerates through an electric potential difference of one volt. Thus it is 1 volt (1 joule per coulomb) multiplied by the electron charge (1 e, or 1.60217 to 120 keV In physics, the electron volt is a unit of energy equal to approximately 1.602×10−19 J. By definition, it is equal to the amount of kinetic energy gained by a single unbound electron when it accelerates through an electric potential difference of one volt. Thus it is 1 volt (1 joule per coulomb) multiplied by the electron charge (1 e, or 1.60217. They are shorter in wavelength than UV Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than x-rays, in the range 10 nm to 400 nm, and energies from 3eV to 124 eV. It is so named because the spectrum consists of electromagnetic waves with frequencies higher than those that humans identify as the colour violet rays and longer than gamma rays Gamma rays are electromagnetic radiation of high frequency (very short wavelength). They are produced by sub-atomic particle interactions such as electron-positron annihilation, neutral pion decay, radioactive decay, fusion, fission or inverse Compton scattering in astrophysical processes. Gamma rays typically have frequencies above 1019 Hz, and. In many languages, X-radiation is called Röntgen radiation, after Wilhelm Conrad Röntgen Wilhelm Conrad Röntgen was a German physicist, who, on 8 November 1895, produced and detected electromagnetic radiation in a wavelength range today known as x-rays or Röntgen rays, an achievement that earned him the first Nobel Prize in Physics in 1901.:1, who is generally credited as their discoverer, and who had named them X-rays to signify an unknown type of radiation.[1]:1–2 Correct spelling of X-ray(s) in the English language includes the variants x-ray(s) and X ray(s).[2] XRAY is used as a communications code word for the letter x. [3]
X-rays from about 0.12 to 12 keV (10 to 0.10 nm wavelength) are classified as "soft" X-rays, and from about 12 to 120 keV (0.10 to 0.01 nm wavelength) as "hard" X-rays, due to their penetrating abilities.
Hard X-rays can penetrate solid objects, and their largest use is to take images of the inside of objects in diagnostic Medical diagnosis refers both to the process of attempting to determine the identity of a possible disease or disorder and to the opinion reached by this process radiography Radiography is the use of the property of X-rays to cross materials to view inside objects. The impact on society of this technique has been immense with application fields including medical, non-destructive testing, food inspection, security and archeology and crystallography X-ray crystallography is a method of determining the arrangement of atoms within a crystal, in which a beam of X-rays strikes a crystal and diffracts into many specific directions. From the angles and intensities of these diffracted beams, a crystallographer can produce a three-dimensional picture of the density of electrons within the crystal. As a result, the term X-ray is metonymically Metonymy is a figure of speech used in rhetoric in which a thing or concept is not called by its own name, but by the name of something intimately associated with that thing or concept. For instance, "Washington", as the capital of the United States, can be used as a metonym (an instance of metonymy) for its government used to refer to a radiographic image produced using this method, in addition to the method itself. By contrast, soft X-rays can hardly be said to penetrate matter at all; for instance, the attenuation length of 600 eV (~ 2 nm) x-rays in water is less than 1 micrometer.[4] X-rays are a form of ionizing radiation Ionizing radiation consists of subatomic particles or electromagnetic waves that are energetic enough to detach electrons from atoms or molecules, ionizing them. The occurrence of ionization depends on the energy of the impinging individual particles or waves, and not on their number. An intense flood of particles or waves will not cause, and exposure to them can be a health hazard.
The distinction between X-rays and gamma rays Gamma rays are electromagnetic radiation of high frequency (very short wavelength). They are produced by sub-atomic particle interactions such as electron-positron annihilation, neutral pion decay, radioactive decay, fusion, fission or inverse Compton scattering in astrophysical processes. Gamma rays typically have frequencies above 1019 Hz, and has changed in recent decades. Originally, the electromagnetic radiation emitted by X-ray tubes An X-ray tube is a vacuum tube that produces X-rays. They are used in X-ray machines. X-rays are part of the electromagnetic spectrum, an ionizing radiation with wavelengths shorter than ultraviolet light. X-ray tubes evolved from experimental Crookes tubes with which X-rays were first discovered in the late 1800s, and the availability of this had a longer wavelength In physics, the wavelength of a sinusoidal wave is the spatial period of the wave – the distance over which the wave's shape repeats. It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a characteristic of both traveling waves and than the radiation emitted by radioactive Radioactive decay is the process by which an unstable atomic nucleus loses energy by emitting ionizing particles or radiation. The emission is spontaneous in that the nucleus decays without collision with another particle. This decay, or loss of energy, results in an atom of one type, called the parent nuclide, transforming to an atom of a nuclei The nucleus is the very dense region consisting of nucleons at the center of an atom. Almost all of the mass in an atom is made up from the protons and neutrons in the nucleus, with a very small contribution from the orbiting electrons. It was discovered in 1911, as a result of Ernest Rutherford's interpretation of the famous 1909 Rutherford (gamma rays).[4] Older literature distinguished between X- and gamma radiation on the basis of wavelength, with radiation shorter than some arbitrary wavelength, such as 10−11 m, defined as gamma rays.[5] However, as shorter wavelength continuous spectrum "X-ray" sources such as linear accelerators A linear particle accelerator is a type of particle accelerator that greatly increases the velocity of charged subatomic particles or ions by subjecting the charged particles to a series of oscillating electric potentials along a linear beamline; this method of particle acceleration was invented in 1928 by Rolf Widerøe and longer wavelength "gamma ray" emitters were discovered, the wavelength bands largely overlapped. The two types of radiation are now usually distinguished by their origin: X-rays are emitted by electrons outside the nucleus, while gamma rays are emitted by the nucleus The nucleus of an atom is the very dense region, consisting of nucleons , at the center of an atom. Almost all of the mass in an atom is made up from the protons and neutrons in the nucleus, with a very small contribution from the orbiting electrons.[4][6][7][8]
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Units of measure and exposure
The measure of X-rays ionizing Ionization is the physical process of converting an atom or molecule into an ion by adding or removing charged particles such as electrons or other ions. This is often confused with dissociation ability is called the exposure:
- The coulomb The coulomb is the SI derived unit of electric charge, and is approximately equal to the charge of 6.24151 × 1018 protons or −6.24151 × 1018 electrons. It is named after Charles-Augustin de Coulomb per kilogram The kilogram is the base unit of mass in the International System of Units (SI, from the French Le Système International d’Unités),[Note 2] which is the modern standard governing the metric system. The kilogram is defined as being equal to the mass of the International Prototype Kilogram (IPK),[Note 3] which is almost exactly equal to the mass (C/kg) is the SI unit of ionizing radiation Ionizing radiation consists of subatomic particles or electromagnetic waves that are energetic enough to detach electrons from atoms or molecules, ionizing them. The occurrence of ionization depends on the energy of the impinging individual particles or waves, and not on their number. An intense flood of particles or waves will not cause exposure, and it is the amount of radiation required to create one coulomb of charge of each polarity in one kilogram of matter.
- The roentgen (R) is an obsolete traditional unit of exposure, which represented the amount of radiation required to create one electrostatic unit of charge of each polarity in one cubic centimeter of dry air. 1.00 roentgen = 2.58×10−4 C/kg
However, the effect of ionizing radiation on matter (especially living tissue) is more closely related to the amount of energy In physics, energy is a quantity that is often understood as the ability to perform work. This quantity can be assigned to any particle, object, or system of objects as a consequence of its physical state deposited into them rather than the charge generated Electric charge is a fundamental conserved property of some subatomic particles, which determines their electromagnetic interaction. Electrically charged matter is influenced by, and produces, electromagnetic fields. The interaction between a moving charge and an electromagnetic field is the source of the electromagnetic force, which is one of the. This measure of energy absorbed is called the absorbed dose Absorbed dose is a measure of the energy deposited in a medium by ionizing radiation. It is equal to the energy deposited per unit mass of medium, and so has the unit J/kg, which is given the special name Gray (Gy):
- The gray The gray is the SI unit of absorbed radiation dose due to ionizing radiation (for example, X-rays) (Gy), which has units of (Joules/kilogram), is the SI unit of absorbed dose Absorbed dose is a measure of the energy deposited in a medium by ionizing radiation. It is equal to the energy deposited per unit mass of medium, and so has the unit J/kg, which is given the special name Gray (Gy), and it is the amount of radiation required to deposit one joule The joule , named after James Prescott Joule, is the derived unit of energy in the International System of Units. It is the energy expended in applying a force of one Newton through a distance of one metre (1 Newton·metre or N·m). In terms of dimensions: of energy in one kilogram The kilogram is the base unit of mass in the International System of Units (SI, from the French Le Système International d’Unités),[Note 2] which is the modern standard governing the metric system. The kilogram is defined as being equal to the mass of the International Prototype Kilogram (IPK),[Note 3] which is almost exactly equal to the mass of any kind of matter.
- The rad The rad is a largely obsolete unit of absorbed radiation dose, with symbol rad. The rad was first proposed in 1918 as "that quantity of X rays which when absorbed will cause the destruction of the [malignant mammalian] cells in question..." It was defined in CGS units in 1953 as the dose causing 100 ergs of energy to be absorbed by one is the (obsolete) corresponding traditional unit, equal to 10 millijoules of energy deposited per kilogram. 100 rad = 1.00 gray.
The equivalent dose The equivalent dose is a measure of the radiation dose to tissue where an attempt has been made to allow for the different relative biological effects of different types of ionizing radiation. Equivalent dose is therefore a less fundamental quantity than radiation absorbed dose, but is more biologically significant. Equivalent dose has units of is the measure of the biological effect of radiation on human tissue. For X-rays it is equal to the absorbed dose Absorbed dose is a measure of the energy deposited in a medium by ionizing radiation. It is equal to the energy deposited per unit mass of medium, and so has the unit J/kg, which is given the special name Gray (Gy).
- The sievert The sievert is the SI derived unit of dose equivalent. It attempts to reflect the biological effects of radiation as opposed to the physical aspects, which are characterised by the absorbed dose, measured in gray. It is named after Rolf Sievert, a Swedish medical physicist famous for work on radiation dosage measurement and research into the (Sv) is the SI unit of equivalent dose, which for X-rays is numerically equal to the gray The gray is the SI unit of absorbed radiation dose due to ionizing radiation (for example, X-rays) (Gy).
- The Roentgen equivalent man The röntgen equivalent in man (or mammal) or rem (symbol rem) is a unit of radiation dose. It is the product of the absorbed dose in röntgens (R) and the biological efficiency of the radiation. More precisely, assuming a radiation weighting factor rW=1, 1 rem equals 1.07185 röntgen. The conversion factor has been readjusted from 1 to 1.07185 so (rem) is the traditional unit of equivalent dose. For X-rays it is equal to the rad or 10 millijoules of energy deposited per kilogram. 1.00 Sv = 100 rem.
Medical X-rays are a significant source of manmade radiation exposure, accounting for 58% in the United States ^ b. English is the de facto language of American government and the sole language spoken at home by 80% of Americans age five and older. Spanish is the second most commonly spoken language in 1987, but since most radiation exposure is natural (82%), medical X-rays only account for 10% of total American radiation exposure.[9]
Reported dosage due to dental X-rays seems to vary significantly. Depending on the source, a typical dental X-ray of a human results in an exposure of perhaps, 3,[10] 40,[11] 300,[12] or as many as 900[13] mrems (30 to 9,000 μSv The sievert is the SI derived unit of dose equivalent. It attempts to reflect the biological effects of radiation as opposed to the physical aspects, which are characterised by the absorbed dose, measured in gray. It is named after Rolf Sievert, a Swedish medical physicist famous for work on radiation dosage measurement and research into the).
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Thu, 26 Aug 2010 22:15:25 GMT+00:00
Scanners Driving Down A Street Near You? NetworkWorld.com If full-body airport scanners are intrusive, how about vans taking x-ray scans while you drive or walk along the sidewalk? By Ms. Smith on Thu, ... Can the government x-ray your car? Examiner.com Full Body Scanners: From Airports to the Streets? Huffington Post (blog) Government's Peep Show Takes to the Road The New American OverTheLimit.info (blog) - Raw Story
Paul McNamara
Wed, 01 Oct 2008 23:23:56 GM
I sent him the link about Roth's . X. -. ray. art and asked whether he thought this would a) work as the artist intends, and b) go over very well at your typical airport security station. His reply: It is beyond me why anyone would do anything ...
