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Gamma counting spectrometry

Zeisler R (2000b) Maintaining accuracy in gamma-ray spectrometry at high count rates. J Radio-anal Nucl Chem 244 507-510. [Pg.153]

Whole organs and tissues Animal placed, backbone down in lucite box and positioned 33 cm from Nal(TI) crystal. Livers and other tissues were counted between two Nal(TI) crystals. Gamma-ray spectrometry No data No data Lloyd et al. 1970... [Pg.202]

Perkins [18] carried out radium and radiobarium measurements in seawater by sorption and direct multidimensional gamma-ray spectrometry. The procedure described includes the removal of radium and barium from water samples on sorption beds of barium sulfate impregnated alumina (0.5-1 cm thick) and direct counting of these beds on a multidimensional y-ray spectrometer. The radioisotopes can be removed at Unear flow rates of sample of up to 1 m/min. [Pg.346]

Plasma and Urine As X-ray Spectrometry Gamma counting Fractionation of arsenic metabolites formed after in vivo incorporation experiments with As 53)... [Pg.159]

After both sets of experiments were completed, the ground-water was drained from the cells and selective chemical extractions of the granite cell walls were performed. The cells were filled with 0.5 mol/L CaCl solution and stirred continuously for 72 h to displace exchangeable radionuclides. After a rinse with demineralized water to remove residual CaCl- solution, the cells were filled with KTOX solution and stirred ror 24 h to remove radionuclides associated with oxyhydroxides. All solutions were analyzed by gamma spectrometry to determine the amounts of radionuclides extracted. Residual activity was measured by direct gamma counting of the cells. [Pg.54]

As test laboratories, gamma-ray spectrometry laboratories are usually engaged in determination of the activities of gamma-ray emitters in samples. In order to determine the activity present in a sample, beside the counting efficiency, the emission probability and the peak ar-... [Pg.230]

Through the sampling head, the pump unit feeds air to the detection head which contains a sequentially advanced filter cartridge that captures alpha and beta emitters for detection. The detection type is gross counting for beta, gamma and spectrometry for alpha particulates using dual passivated silicon detectors. [Pg.429]

Problems with regard to sample uniformity and stability for gamma-ray spectrometry were discussed in Section 12.3.3. The ease of directly placing a sample into a container and counting should not divert the analyst from maintaining uniformity once a sample is prepared. [Pg.255]

Most of the effluent and environmental radioactivity measurements are made using gamma-ray spectrometry. This is a far more cost effective approach than radiochemical analysis the Instrumental measurement can be readily automated, and detection decisions can be made more or less simultaneously for many radionuclides. The validity of those decisions, and of the corresponding detection limits, however, requires either that the peaks be Isolated and lie on a linear baseline, or that a detection limit model be employed which Is more complex than that used for "simple" counting. Baseline or interference model uncertainties should be Included, and an iterative solution is required to estimate the detection limit when spectrum deconvolution is involved. Details are beyond the scope of this chapter, but a relatively simple limiting estimate can be derived by treating the estimated standard error for a low level radionuclide peak of interest as though it were the null standard error, [12, p. 81]. [Pg.184]

Uncertainties due to counting geometry can be controlled much more reliably, since in principle only geometry factors must be considered. Extensive references can be found regarding gamma-ray spectrometry of various source shapes (Debertin and Helmer 1988) and software is available for appropriate calculations (e.g., KAYZERO/SOLCOI 1996). [Pg.1602]

Count the cell pellets (cell-associated binding) and the supernatants (membrane-associated binding) separately by gamma scintillation spectrometry. [Pg.197]

Gas-filled detectors, such as ionization chambers, proportional counters, and Geiger-Miiller counters are mainly sensitive to P-radia-tion. They rarely allow any selection on the basis of energy. Gamma counting with a selection for energy is called gamma spectrometry and is performed by means of scintillation or semiconductor detectors. Currently the gamma spectrometric measurements in neutron activation analysis are only performed with semiconductor detectors. Scintillation counters will therefore be discussed only briefly. [Pg.774]

Event timing is not a great concern in everyday gamma-ray spectrometry. The emphasis is on how much energy is absorbed by the gamma-ray event and how many events occur within a particular counting period, not precisely when within that period they occurred. However, if the gamma-ray detector pulse is to be used in a coincidence system, then the time relationship between pulses from different detectors becomes important. [Pg.52]

For higher energies at high count rates, a transistor reset circuit is used. For gamma-ray spectrometry, one would use a transistor reset preamplifier or TRP. [Pg.69]


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See also in sourсe #XX -- [ Pg.308 ]




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