Radioactive metals, sources

Swedish chemist Jons Jakob Berzelius Radioactive metal named for Thor, the ancient Scandinavian god of war promising as a future source of nuclear energy makes magnesium alloys heat resistant. 

Hazard (Powder) Dangerous fire risk, ignites spontaneously in air. Highly toxic, radioactive material, source of ionizing radiation. TLV (including metal and all compounds, as uranium) 0.2 mg/m3 STEL 0.6 mg(U)/m3. 

Radioactive sources are favored for use in IMS analyzers because they provide stable and reliable operation, with ionization chemistry that is well suited for most current applications of IMS. Furthermore, radioactive foils do not require an external power supply and have no moving parts or maintenance requirements. At present, the most widely used and best understood of all ion sources for IMS is still the long-favored radioactive i source, which is also widely used in electron capture detectors (ECDs) for gas chromatography (GC). The preferred radioactive source is 10 mCi (3.7 10 Bq) of Ni coated as a thin layer on a metal strip, generally nickel or gold. The maximum energy of the electrons emitted from the Ni source... 

Figure 10.23 shows a schematic of a Mdssbauer spectrometer. The radioactive Co source is embedded in a nonmagnetic matrix, which is chosen so as not to affect the sample or to absorb the y-rays too strongly. The system can be calibrated using Fe metal the six peaks seen in Figure 10.24 correspond to the six transitions expected for Fe. The Co source has an emission peak at 14.4 keV ... 

Radioactive contamination of drinking water is a serious matter. Radionuclides (the radioactive metals and minerals that cause this contamination) come from both natural and manmade sources. Naturally occurring radioactive minerals move from underground rock strata and geologic... 

Uranium occurs naturally in variable concentrations in all soils, minerals, rocks and waters. It can also be derived from several anthropogenic sources. Uranium is weakly radioactive and human exposure to the element has long been considered to pose a radiological as well as toxic hazard (WHO, 2004 2008 Smedley et al., 2006). This dissolved toxic radioactive metal may poison drinking water sources and the food chain via contaminated surfaces and groundwater. In recent years, there has been increasing concern that the chemical effects of uranium may also pose a potential hazard to exposed populations. However, there are few if any epidemiological studies that have been able to demonstrate any resultant harm, even in occupational contexts (The Royal Society, 2001). 

Figure 3.9 Diagram of a radioactive ion source and drift tube. The radioactive source is a thin metallic strip impregnated with which delivers a particles. The a particles interact with...

National Institute of Standards and Technology (NIST). The NIST is the source of many of the standards used in chemical and physical analyses in the United States and throughout the world. The standards prepared and distributed by the NIST are used to caUbrate measurement systems and to provide a central basis for uniformity and accuracy of measurement. At present, over 1200 Standard Reference Materials (SRMs) are available and are described by the NIST (15). Included are many steels, nonferrous alloys, high purity metals, primary standards for use in volumetric analysis, microchemical standards, clinical laboratory standards, biological material certified for trace elements, environmental standards, trace element standards, ion-activity standards (for pH and ion-selective electrodes), freezing and melting point standards, colorimetry standards, optical standards, radioactivity standards, particle-size standards, and density standards. Certificates are issued with the standard reference materials showing values for the parameters that have been determined. 

The price per m of the other noble gases is considerably higher (Ne 70, Kr 350 and Xe 3500, and this tends to restrict their usage to specialist applications only. Radon has been used in the treatment of cancer and as a radioactive source in testing metal castings but, because of its short half-life (3.824 days) it has been superseded by more convenient materials. Such small quantities as are required are obtained as a decay product of Ra (1 g of which yields 0.64 cm in 30 days). 

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