Natural gamma radiation

Ziane M.A, Lounis-Mokrani Z, AHab M. (2014) Exposure to indoor radon and natural gamma radiation in some workplaces at Algiers, Algeria. Radiation Protection Dosimetry 1-6. 

Figure 5.37 depicts the basic set up of a wireline logging operation. A sonde is lowered downhole after the drill string has been removed. The sonde is connected via an insulated and reinforced electrical cable to a winch unit at the surface. At a speed of about 600m per hour the cable Is spooled upward and the sonde continuously records formation properties like natural gamma ray radiation, formation resistivity or formation density. The measured data is sent through the cable and is recorded and processed in a sophisticated logging unita the surface. Offshore, this unit will be located in a cabin, while on land it is truck mounted. In either situation data can be transmitted in real time via satellite to company headquarters if required. 

Both side-chain and main-chain scission products are observed when polyacrylates are irradiated with gamma radiation (60). The nature of the alkyl side group affects the observed ratio of these two processes (61,62). 

An extractive study of one can enamel in the presence of food-simulating solvents to determine how gamma radiation from a cobalt-60 source altered the nature and amount of extractives of this enamel. 

Effects of Gamma-radiation on Some Carbohydrates, Hydroxy-acids, and Amino-acids in Aqueous Solutions, S. A. Barker, P. M. Grant, M. Stacey, and R. B. Ward, Nature, 183 (1959) 376-377. 

The Mossbauer effect, discovered by Rudolf L. Mossbauer in 1957, can in short be described as the recoil-free emission and resonant absorption of gamma radiation by nuclei. In the case of iron, the source consists of Co, which decays with a half-life of 270 days to an excited state of Fe (natural abundance in iron 2%). The latter, in turn, decays rapidly to the first excited state of this isotope. The final decay generates a 14.4 keV photon and a very narrow natural linewidth of the order of nano eV. 

What is the nature of the defects seen in the EPR spectra For alkali and alkali earth halogenides it is well known that irradiation with X-ray, neutrons, gamma-radiation, or electrons produce paramagnetic color centers (F-center) [109-111]. If these centers are created in large amounts, they can be stabilized by the formation of metal clusters as observed for MgCl2 films after prolonged electron radiation [106]. From the temperature dependence... 

The metal is radioactive and does not occur in nature, as the half-life of all isotopes is shorter than 5 million years. It is found in readily isol-able amounts in nuclear reactors. It is an effective "rust-preventer" for iron and steel in special applications. The metastable isotope "Tc has a half-life of only 6 hours and is therefore used as a gamma radiator in medicine (radiation therapy and diagnostics). Of very little commercial importance. 

Pohl-Ruling, J. and P. Fischer, The Dose Effect Relationship of Chromosome Aberrations to Alpha and Gamma Irradiation in a Population Subjected to an Increased Burden of Natural Radioactivity, Radiation Research 80 61-81 (1979)... 

Exposure to natural sources of radiation is unavoidable. Externally, individuals receive cosmic rays, terrestrial X-rays, and gamma radiation. Internally, naturally occurring radionuclides of Pb, Po, Bi, Ra, Rn, K, C, H, U, and Th contribute to the natural radiation dose from inhalation and ingestion. Potassium-40 is the most abundant radionuclide in foods and in all tissues. The mean effective human dose equivalent from natural radiations is 2.4 milliSieverts (mSv). This value includes the lung dose from radon daughter products and is about 20% higher than a 1982 estimate that did not take lung dose into account (Table 32.4). 

High-energy radiation may be classified into photon and particulate radiation. Gamma radiation is utilized for fundamental studies and for low-dose rate irradiations with deep penetration. Radioactive isotopes, particularly cobalt-60, produced by neutron irradiation of naturally occurring cobalt-59 in a nuclear reactor, and caesium-137, which is a fission product of uranium-235, are the main sources of gamma radiation. X-radiation, of lower energy, is produced by electron bombardment of suitable metal targets with electron beams, or in a... 

The preservation of nutrient solutions at the concentrations occurring in natural seawater is a major challenge to the routine production of a nutrient reference material. Preservation techniques must be developed that maintain concentrations stable for periods of at least one to two years. Gamma radiation will produce nitrite that is unstable. Therefore this method appears to be problematic. The feasibility of other techniques, such as autoclaving, ultra-violet or microwave radiation, freezing, and acidification, should be evaluated. 

In the last four years of the nineteenth century, scientists in France— notably Henri Becquerel and Marie and Pierre Curie—discovered that certain elements are radioactive. That is, their atoms naturally emit positively charged particles (alpha particles), negatively charged particles (beta particles), and energy (gamma radiation). 

Gamma-ray log This is a log of the natural formation radioactivity level. Gamma radiation is measured along the borehole to determine the rock and sediment formations... 

ISOTOPES Cs-133 is the only stable isotope of cesium, and it makes up all of the naturally occurring cesium found in the Earth s crust. In addition to Cs-133 there are about 36 radioactive isotopes of Cs, most of which are artificially formed in nuclear reactors. All are produced in small numbers of atoms with relatively short half-lives. The range of Cs isotopes is from Cs-113 (amu = 112.94451) to Cs-148 (amu = 147.94900). Most of these radioisotopes produce beta radiation as they rapidly decay, with the exception of Cs-135, which has a half-life of 3x10 yr, which makes it a useful research tool. Cs-137, with a half-life of 33 years, produces both beta and gamma radiation. 

Cross-linking of natural rubber and synthetic polyisoprene has been studied by several investigators using electron beam and gamma radiation. The general conclusion is that the yield of chemical cross-links, G(X), is constant with dose and independent of dose rate and the type of radiation used. Effects of temperature are reported in Bohm and Tveekrem. ... 

Another exposure tool is available in gamma radiation. While the correlation is not always perfect, there is a high degree of similarity in the response of polymers to the radiation from 60Co and from 50 keV electrons. Because of the penetrating nature of gamma rays, the exposure is not restricted to thin films or small amounts of polymer. Also, the absorbed dose is not complicated by the depth-dose function which must be used when electron-... 

Pierce, T. B., P. F. Peck, and W. M. Henry Determination of Carbon in Steels by Measurement of the Prompt Gamma-Radiation Emitted During Proton Bombardment. Nature 204, 571 (1964). 

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