Radiation detection methods

Smith, M. R., Wyse, E. J., and Koppenaal, D. W., Radiounuclide detection by inductively coupled plasma mass spectrometry A comparison of atomic and radiation detection methods, J. Radioanal. Nucl. Chem., 160, 341-354, 1992. 

Sugarman 1951). A set of monographs published by the National Research Council over a period of several years, entitled The Radiochemistry of [Element] (NAS-NRC 1960a), traverses the entire periodic table. Another set (NAS-NRC 1960b) of monographs is on radiochemical techniques. Laue and Nash (2003) edited symposium presentations of recently developed chemical and radiation detection methods, together with overviews of historical developments and current needs. 

Plan and perform identification and measurement of radionuclides through a combination of chemical separation and radiation detection methods ... 

The extent of detail depends on the purpose of the report. Even a brief progress report should characterize samples and their data so that they can be traced to more detailed records. The significance of the results in terms of magnitude, reliability, and pertinence must be understandable by the reader. Detailed reports for long periods or at the completion of the project should also provide all necessary information on sample collection and processing, analytical and radiation detection methods, quality assurance, and data processing, either as part of the report or by references. The names of the persons who participated in the program and their individual contributions are an important part of the record to permit further detailed review. 

The applicability of radioactive substances in analytical chemistry depends on the properties of the radioactive material (type, energy, and half-life of the radioactive atoms), the availability of the radioactive material, and the availability of suitable radiation detection methods. 

There is a wide and excellent selection of literature available related to radiation detection methods in the field of radioactivity analysis. 

Induction electron accelerators - betatrons- are widely used as radiation sources in industrial flaw detection of materials and articles of high thickness. However, relatively low radiation intensity has become the barrier for the most wider betatron use in this area. For the efficiencyincrease of radiation control method of articles, as well as for the possibility to control materials and articles of the most thickness the significant increase of betatron radiation intensity has been required. 

Knowledge about the radiations from each isotope is important because as the uses of the radioisotopes have iacreased, it has become necessary to develop sensitive and accurate detection methods designed to determine both the presence of these materials and the amount present. These measurements determine the amount of radiation exposure of the human body or how much of the isotope is present ia various places ia the environment. For a discussion of detection methods used see References 1 and 2. 

Physical detection methods are based on inclusion of substance-specific properties. The most commonly employed are the absorption or emission of electromagnetic radiation, which is detected by suitable detectors (the eye, photomultiplier). The / -radiation of radioactively labelled substances can also be detected directly. These nondestructive detection methods allow subsequent micropreparative manipulation of the substances concerned. They can also be followed by microchemical and/or biological-physiological detection methods. 

All the usual detection methods are naturally suitable for the detection of such substances (Fig 2) In addition, however, it is also possible to detect the ) -radiation they produce The selectivity of the detection is, thus, increased This, however,... 

In our laboratory we have recently implemented this detection method, that we call soft El ionization.31-34 It is analogous to soft PI by synchrotron radiation, but has the bonus that one can also derive branching ratios, a very important piece of information when studying multichannel reactions, and this affords an attractive alternative to the use of PI by a synchrotron source. 

Radiation detection circuit currents or pulse rates vary over a wide range of values. The current output of an ionization chamber may vary by 8 orders of magnitude. For example, the range may be from 10"13 amps to 10"5 amps. The most accurate method to display this range would be to utilize a linear current meter with several scales, and the capability to switch those scales. This is not practical. A single scale which covers the entire range of values is used. This scale is referred to as logarithmic. 

The use of two separate electrical or mechanical zones of detectors, both of which must be actuated before the confirmation of a fire or gas detection. For example, the detectors in one zone could all be placed on the north side of a protected area, and positioned to view the protected area looking south, while the detectors in the second zone would be located on the south side and positioned to view the northern area. Requiring both zones to be actuated reduces the probability of a false alarm activated by a false alarm source such as welding operations, from either the north or the south outside the protected area. However this method is not effective if the zone facing away from the source, sees the radiation. Another method of cross zoning is to have one set of detectors cover the area to be protected and another set located to face away from the protected area to intercept external sources of nuisance UV. If welding or lighting should occur outside the protected area, activation of the alarm for the protected area would be inhibited by second... 

Pulse radiolysis, using as time-resolved detection methods optical absorption, luminescence, electrical conductivity or electron spin resonance can be expected to give information on the formation of transient or permanent radiation products and on their movement. 

Recent developments in laser technology and fast detection methods now allow the kinetic behaviour of the excited state species arising from absorption of radiation by polymers to be studied on time-scales down to the picosecond region ( ). An example of a time-resolved fluorescence spectrometer which can be used to study such ultrafast phenomena is illustrated in Figure 5 Q). 

Other localization methods rely on mass spectrometry in vaporized parts of the sample such as secondary ion mass spectrometry, SIMS, and other techniques [77, 78]. Here, atomic boron is detected. In addition, the specific electron shell energy of boron (usually the K shell) can be used for visualization [66, 79]. A combination of quantitative techniques with suboptimal spatial resolution and the high-resolution detection methods can give an indication about the radiation response to be expected. All these techniques require, however, that the compound in ques-... 

G.F.KNOLL, Radiation detection and measurement (Wiley, New York, 1979). S.COCKERTON B.K.TANNER, Adv. X-ray Anal., 38, 371 (1995) S.COCKERTON, B.K. TANNER G.DERBYSHIRE, Nuclear Instruments and Methods in Physics Research, B97,561 (1995). 

Borsa, J. Chu, R. Sun, J. Linton, N. Hunter, C. Radiat. Phys. Chem. 2002, 63, 271. Murray, C.H., Stewart, E.M., Gray, R., Pearce J. Eds. Detection Methods for Irradiated Foods—Current Status) The Royal Society of Chemistry, Information Services London, 1996. Delincee, H. Radiat. Phys. Chem. 2002, 63, 455. 

Another method of radiation detection that has value in biochemistry is the use of gas ionization chambers. The most common device that uses this technique is the Geiger-Miiller tube (G-M tube). When (S particles pass through a gas, they collide with atoms and may cause ejection of an electron from a gas atom. This results in the formation of an ion pair made up... 

All methods of radiometric analysis involve, of course, the use. of various radiation detection devices, The devices available for measuring radioactivity will vary with the types of radiations emitted by the radioisotope and the kinds of radioactive material. Ionization chambers are used for gases Geiger-Miiller and proportional counters for solids liquid scintillation counters for liquids and solutions and solid crystal or semi-conductor detector scintillation counters for liquids and solids emitting high-energy radiations. Each device can be adopted to detect and measure radioactive material in another state, e.g., solids can be assayed in an ionization chamber. The radiations interact with the detector to produce a signal,... 

In this chapter we will consider the techniques developed to detect and quantitatively measure how much ionization and/or excitation is caused by different nuclear radiations. As all radiation creates ionization and/or excitation, we will separate the discussion of detection methods according to the general techniques used to collect and amplify the results of the interaction of the primary radiation with matter rather than by the type of radiation. These detection methods can be classified as (a) collection of the ionization produced in a gas or solid, (b) detection of secondary electronic excitation in a solid or liquid scintillator, or (c) detection of specific chemical changes induced in sensitive emulsions. 

One of the characteristics of an ideal detection method is that it should be capable of providing an estimate of the absorbed dose. Thus considerable effort has been directed towards studying the parameters which might influence the intensity of the radiation-induced signal and the conditions under which it might no longer be detectable. 

Delincee, H. (1993). Control of irradiated food Recent developments in analytical detection methods. Radiat. Phvs. Chem. 42. 351. 

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