Radiation.png (Image PNG, 1134x1333 pixels) Radiation Dosage Chart. Interactive Chart of Nuclides. Dosiskonversionsfaktor. Der Dosiskonversionsfaktor hängt von physikalischen und physiologischen Parametern ab: Zusammensetzung des Strahlers (Isotop bzw. Isotopengemisch)Art der Strahlung des Isotops (Alpha-, Beta- oder Gamma-Strahlung)Strahlungsenergien des IsotopsArt der Aufnahme des Strahlers (über Haut, Lunge oder Magen-Darm-Schleimhäute) Die Dosiskonversionsfaktoren einiger Elemente betragen:[1] Bei der Bestimmung von Dosiskonversionsfaktoren wird zunächst versucht, aus der spezifischen Empfindlichkeit der betroffenen Gewebe und Modellannahmen (etwa zur Verteilung der Folgeprodukte in den Atmungsorganen, zur Art der Atmung und der körperlichen Tätigkeit) eine Organdosis zu berechnen.[2] Durch den Vergleich mit epidemiologischen Studien wird dann der Dosiskonversionsfaktor ermittelt. Innerhalb der Strahlenschutzverordnung eines Landes werden Dosiskonversionsfaktoren tabelliert.[3]
Radioactivity (2) Radioactivity Threats There are three possible radioactive threats for humans in a contaminated area. The most dangerous threat are airborn particles being absorbed by the lung tissue. Right after that come particles absorbed by food. Radioactive particles do the most damage from inside, where no skin stops them or lowers their strength. For example alpha radiation from outside the human body is not able to do any harm because of being reflected by the skin. Dose If you are interested in measuring the radioactivity dose you will soon fall over a bunch of units. Dose Rate The dose rate is given in dose per hour (e.g. sievert / hour).
After I searched for some more additional info on Wolfram Alpha I found another unit, "röntgen equivalents physical" which was meant be used for the absorbed dose, but it was never introduced. Do you want to know more? Wikipedia: Absorbed DoseEquivalent DoseRadiation Sickness (german article used for creating the picture) Röntgen. Röntgen or Roentgen may refer to: Coulomb. The coulomb (named after Charles-Augustin de Coulomb, unit symbol: C) is a fundamental unit of electrical charge, and is also the SI derived unit of electric charge (symbol: Q or q).
It is equal to the charge of approximately 6.241×1018 electrons. Its SI definition is the charge transported by a constant current of one ampere in one second: One coulomb is also the amount of excess charge on a capacitor of one farad charged to a potential difference of one volt: Name and notation[edit] This SI unit is named after Charles-Augustin de Coulomb. As with every International System of Units (SI) unit whose name is derived from the proper name of a person, the first letter of its symbol is upper case (C). However, when an SI unit is spelled out in English, it should always begin with a lower case letter (coulomb), except in a situation where any word in that position would be capitalized, such as at the beginning of a sentence or in capitalized material such as a title. Definition[edit] Equivalent dose. External dose quantities used in radiation protection and dosimetry Relationships of SI external "protection" dose quantities Equivalent dose is a radiation-weighted dose quantity which takes into account the type of ionizing radiation producing the dose.
Equivalent dose is used in radiological protection to represent the stochastic (probability of cancer induction and genetic effects) but not deterministic effects (severity of acute tissue effects) of ionizing radiation. Uses[edit] The equivalent dose is calculated by multiplying the absorbed dose by a radiation weighting factor appropriate to the type and energy of radiation. External dose[edit] Internal dose[edit] The ICRP states "Radionuclides incorporated in the human body irradiate the tissues over time periods determined by their physical half-life and their biological retention within the body. Calculation[edit] The radiation weighting factor represents the relative biological effectiveness of the radiation. Where History[edit] Sievert. The sievert (symbol: Sv) is a derived unit of ionizing radiation dose in the International System of Units (SI). It is a measure of the health effect of low levels of radiation on the human body. Quantities that are measured in sieverts are intended to represent the stochastic health risk, which for radiation dose assessment is defined as the probability of cancer induction and genetic damage.[1] To enable consideration of stochastic health risk, calculations are performed to convert the physical quantity absorbed dose into equivalent and effective doses, the details of which depend on the radiation type and biological context.
For applications in radiation protection and dosimetry assessment the International Committee on Radiation Protection (ICRP) and International Commission on Radiation Units and Measurements (ICRU) have published recommendations and data which are used to calculate these. One sievert equals 100 rem. Definition[edit] CIPM definition of the sievert[edit] In summary: 1.
Joule. In terms firstly of base SI units and then in terms of other SI units: One joule can also be defined as: Usage[edit] This SI unit is named after James Prescott Joule. As with every International System of Units (SI) unit whose name is derived from the proper name of a person, the first letter of its symbol is upper case (J). However, when an SI unit is spelled out in English, it should always begin with a lower case letter (joule), except in a situation where any word in that position would be capitalized, such as at the beginning of a sentence or in capitalized material such as a title. Note that "degree Celsius" conforms to this rule because the "d" is lowercase. —Based on The International System of Units, section 5.2. Confusion with newton-metre[edit] In angular mechanics, torque is analogous to the linear Newtonian mechanics parameter of force, moment of inertia to mass, and angle to distance.
Where E is the energy, τ is the torque, and θ is the angle moved (in radians). Exajoule[edit] Röntgen equivalent man. A rem is a large dose of radiation, so the millirem (mrem), which is one thousandth of a rem, is often used for the dosages commonly encountered, such as the amount of radiation received from medical x-rays and background sources. Unit conversion[edit] The rem and millirem are CGS units in widest use among the American public, industry, and government.[3] SI units are the norm outside of the US, and they are increasingly encountered within the US in academic, scientific, and engineering environments.
The SI unit of dose equivalent is the sievert (Sv); conversion is straightforward, as 1 Sv = 100 rem by definition: The conventional units for dose rate is mrem/h. Regulatory limits and chronic doses are often given in units of mrem/yr or rem/yr, where they are understood to represent the total amount of radiation allowed (or received) over the entire year. 1 mrem/h = 8766 mrem/yr 0.1141 mrem/h = 1000 mrem/yr 8 h = 1 day 40 h = 1 week 50 week = 1 yr 1 mrem/h = 2000 mrem/yr 0.5 mrem/h = 1000 mrem/yr. Absorbed dose. Uses[edit] External dose quantities used in radiation protection and dosimetry Radiological protection[edit] The quantity absorbed dose is of fundamental importance in radiological protection for calculating radiation dose. However, absorbed dose is a physical quantity and used unmodified is not an adequate indicator of the likely health effects in humans.
It has been found that for stochastic radiation risk (defined as probability of cancer induction and genetic effects) consideration must be given to the type of radiation and the sensitivity of the irradiated tissues, which requires the use of modifying factors to allow for these effects. Conventionally therefore, unmodified absorbed dose is not used for comparing stochastic risks but only used to compare against deterministic effects (severity of acute tissue effects that are certain to happen) such as in acute radiation syndrome. Other uses[edit] Component survivability[edit] Food irradiation[edit] Computation[edit] More precisely,[4] Where. Röntgen equivalent physical.
References[edit] Jump up ^ Cantrill, S.T; H.M. Parker (1945-01-05). The Tolerance Dose. Argonne National Laboratory: US Atomic Energy Commission. Retrieved 14 May 2012. See also[edit] Rad (unit) The material absorbing the radiation can be human tissue or silicon microchips or any other medium (for example, air, water, lead shielding, etc.). A dose of under 100 rad will typically produce no immediate symptoms other than blood changes. 100 to 200 rad delivered in less than a day will cause acute radiation syndrome, (ARS) but is usually not fatal. Doses of 200 to 1,000 rad delivered in a few hours will cause serious illness with poor outlook at the upper end of the range.
Doses of more than 1,000 rad are almost invariably fatal.[2] The same dose given over a longer period of time is less likely to cause ARS. Dose thresholds are about 50% higher for dose rates of 20 rad/h, and even higher for lower dose rates.[3] Radiation increases the risk of cancer and other stochastic effects at any dose. The International Commission on Radiological Protection maintains a model of these risks as a function of absorbed dose and other factors. Gray (unit) One gray is the absorption of one joule of energy, in the form of ionizing radiation, per kilogram of matter.
The CIPM says that "in order to avoid any risk of confusion between the absorbed dose D and the dose equivalent H, the special names for the respective units should be used, that is, the name gray should be used instead of joules per kilogram for the unit of absorbed dose D and the name sievert instead of joules per kilogram for the unit of dose equivalent H".[5] This SI unit is named after Louis Harold Gray. As with every International System of Units (SI) unit whose name is derived from the proper name of a person, the first letter of its symbol is upper case (Gy).
However, when an SI unit is spelled out in English, it should always begin with a lower case letter (gray), except in a situation where any word in that position would be capitalized, such as at the beginning of a sentence or in capitalized material such as a title. Radioactive decay. Alpha decay is one example type of radioactive decay, in which an atomic nucleus emits an alpha particle, and thereby transforms (or 'decays') into an atom with a mass number decreased by 4 and atomic number decreased by 2.
Many other types of decays are possible. Radioactive decay, also known as nuclear decay or radioactivity, is the process by which a nucleus of an unstable atom loses energy by emitting particles of ionizing radiation. A material that spontaneously emits this kind of radiation—which includes the emission of energetic alpha particles, beta particles, and gamma rays—is considered radioactive. Radioactive decay is a stochastic (i.e. random) process at the level of single atoms, in that, according to quantum theory, it is impossible to predict when a particular atom will decay.[1] However, the chance that a given atom will decay is constant over time.
There are many different types of radioactive decay (see table below). Discovery and history[edit] Types of decay[edit] Counts per minute. The measurement of ionizing radiation is sometimes expressed as being a rate of counts per unit time registered by a radiation monitoring instrument, of which counts per minute and counts per second are commonly used.
This measurement is only of the rate of events registered by the measuring instrument, not the rate of events at the point of original emission. For radioactive decay measurements it must not be confused with disintegrations per unit time (dpm), which represents the rate of atomic disintegration events at the source of the radiation. Count rates are normally associated with the measurements of particles, such as alpha particles and beta particles. For gamma ray and X-ray dose measurements a unit such as the sievert is normally used. Count rates[edit] Counts per minute (cpm) is a measure of the detection rate of ionization events per minute. Conversion to dose rate[edit] Geiger-Müller counter with dual counts/dose rate display. Count rates versus disintegration rates[edit] Becquerel. Definition[edit] 1 Bq = 1 s−1[2] A special name was introduced for the reciprocal second (s−1) to represent radioactivity to avoid potentially dangerous mistakes with prefixes.
For example, 1 µs−1 could be taken to mean 106 disintegrations per second: 1·(10−6 s)−1 = 106 s−1.[3] Other names considered were hertz (Hz), a special name already in use for the reciprocal second, and fourier (Fr).[3] The hertz is now only used for periodic phenomena.[2] This SI unit is named after Henri Becquerel. Prefixes[edit] Like any SI unit, Bq can be prefixed; commonly used multiples are kBq (kilobecquerel, 103 Bq), MBq (megabecquerel, 106 Bq), GBq (gigabecquerel, 109 Bq), TBq (terabecquerel, 1012 Bq), and PBq (petabecquerel, 1015 Bq). Relationship to the curie[edit] The becquerel succeeded the curie (Ci),[7] an older, non-SI unit of radioactivity based on the activity of 1 gram of radium-226.
Conversion factors: 1 Ci = 3.7×1010 Bq = 37 GBq 1 μCi = 37,000 Bq = 37 kBq 1 Bq = 2.7×10−11 Ci = 2.7×10−5 µCi With. Curie. Aktivität (Physik) Becquerel (Einheit) Curie (Einheit) Grenzwerte. Ionizing radiation.