Radionuclides production

Frank M., Schwaz B., Baumann S., Kubik P.W., Suter M., and Mangini A. (1997) A 200 kyr record of cosmogenic radionuclide production rate and geomagnetic field intensity from lOBe in globally stacked deep-sea sediments. Earth Planet Sci. Lett. 149, 121-129. 

The high energy primary cosmic rays produce many secondary neutrons and protons which in turn are responsible for most of the spallation reactions resulting in radionuclide production in the atmosphere. The formation of these radionuclides occurs at reaction thresholds of 10-40 M.e.v. Because of local ionization losses the secondary protons lose their... 

An alternative means of radionuclide production employs neutron capture reactions in nonfissile nuclides. Again a high-purity target is used and a mixture of the unconverted target material, the... 

Separation during production. In some cases, the gaseous radionuclide product can be Isolated during Its production, l.e., during the bombardment of the target, and thus a "zero time" separation can be realized. The study of 20-second C10 produced by the B10(p,n) reaction (228,229) can be cited as a typical example of such a separation technique. 

The radioiodine 123I, on the other hand, is very useful in nuclear medicine because it has good radiation characteristics for scintigraphy, such as decay by electron capture, a half-life of 13 h, and y emmision of 159 keV. However, the much shorter half-life, together with the more complex radionuclide production, makes this radionuclide less available and more expensive compared to 131I. 

Reedy R. C. (1990) Cosmogenic-radionuclide production rates in mini-spherules. Lunar Planet Sci. XXL Lunar and Planetary Institute, Houston, pp. 1001-1002. 

High flux radionuclide production reactor meltdown... 

The third means of radionuclide production involves target irradiation by ions accelerated in a cyclotron. One example of this approach is provided by the production of Ge, which decays with a 280 day half-life to the positron emitter Ga. Proton irradiation of Ga produces Ge in a (p,2n) reaction. After dissolution of the target material a solution of the Ge product in concentrated HCl is prepared and adsorbed on an alumina column which has been pre-equilibrated with 0.005 M EDTA (ethylenediaminetetraacetate) solution. The Ga daughter may then be eluted using an EDTA solution in a system which provides the basis of a Ga generator. Cyclotron production of radionuclides is expensive compared with reactor irradiations, but higher specific activities are possible than with the neutron capture process. Also, radionuclides with particularly useful properties, and which cannot be obtained from a reactor, may be prepared by cyclotron irradiation. In one example, cyclotron produced Fe, a positron emitter, may be used for bone marrow imaging while reactor produced Fe, a /3-emitter, is unsuitable. " ... 

A point of consideration for the positive ion cyclotron is that the internal beam of positrons of variable energy can be utilized for radionuclide production by placing a probe with the target at different radial positions. The negative ion cyclotron does not have this provision. 

McCarthy TJ, Welch MJ (1998). The state of positron emitting radionuclide production in 1997. Semin Nucl Med XXVIF235... 

Silvester DJ, Waters SL (1979). Radionuclide production. In Sodd VJ, Allen DR, Hoogland DR, Ice RD (eds) Radiopharmaceuticals II. Society of Nuclear Medicine, New York, p 727... 

Basic nuclear science includes the synthesis of radionuclides, production of new elements, generation of radioactive and exotic nuclear beams, determination of nuclear properties, and applications of nuclear spectroscopy. 

According to the World Nuclear Industry Handbook 2000, 239 research and test reactors were in operation throughout the world at the end of 1999. While the smaller research reactors may have an operating power 1 kW, and do not need forced cooling, the larger test reactors operate at 50 MWn,. Many of these reactors have facilities for commercial radionuclide production. 

Radionuclide Production Method Ey (abundence) Ti/2phys Labeling Methods... 

Elementary Practical Radiochemistry (Ladd and Lee 1964) contains 20 brief experiments that illustrate detection techniques such as measurement of ingrowth and decay, as well as ion exchange, extraction, and coprecipitation. The text Radioisotope Laboratory Techniques (Faires and Boswell 1981) primarily addresses nuclear physics, radionuclide production, and counting techniques. It briefly mentions laboratory apparatus but omits discussion of separation techniques. 

If the produced atom is radioactive, the rate of radionuclide production in terms of the disintegration rate [shown in Eq. (2.4)] is Rk. The disintegration rate of the accumulated atoms, balancing the production and decay rates, is then... 

Shortly after the beginning of photonuclear research in 1934, photoreactions were exploited for analytical purposes as well as for radionuclide production. 

Radionuclides are produced by nuclear reactions. These nuclear reactions can take place between highly accelerated atomic nuclei or between nuclei and nucleons (e.g., protons). To overcome the Coulomb barrier the charged nuclei or nucleons have to be provided with high kinetic energies. This is achieved by the use of accelerator systems such as cyclotrons, synchrotrons, and linear accelerators. Frequently nuclear reactors are used for radionuclide production because the uncharged neutrons... 

Nowadays gamma-ray spectrometry is the most important tool for radio assay. Quality control in radionuclide production, control of reactor operation, surveillance of the environment, and radio activation analysis are only a few examples for the application of gamma-ray spectrometry. 

Use Radionuclide Production method Radiation emitted Half-life... 

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