Perturbation correction for ionometric determination of absorbed dose in a graphite phantom for60Co gamma rays

1983 ◽  
Vol 28 (4) ◽  
pp. 375-388 ◽  
Author(s):  
M Boutillon
Keyword(s):  
Gamma Rays ◽  
Absorbed Dose ◽  
Ionometric Determination

Compartmental transfer of mercury released from amalgam

1997 ◽  
Vol 16 (11) ◽  
pp. 667-672 ◽  
Author(s):  
S. Halbach ◽  
L. Kremers ◽  
H. Willruth ◽  
A. Mehl ◽  
G. Welzl ◽  
...  
Keyword(s):  
Oral Cavity ◽  
Urinary Excretion ◽  
Total Mercury ◽  
Excretion Rate ◽  
Absorbed Dose ◽  
Correlation Coefficients ◽  
Urinary Excretion Rate ◽  
Amalgam Fillings

The number of amalgam-covered surfaces and the occlusal area of the fillings, the concentrations of total mercury in plasma, erythrocytes and urine, the urinary excretion rate, and the absorbed daily doses estimated by two separate methods from intra-oral Hg emission were determined in 29 volunteers with a low amalgam load. The transfer ofHg from the fillings via the oral cavity and blood to urinary excretion was evaluated by multiple correla tions between these variables. In addition, the combina tion of variables most representative of the entire compartmental transfer of amalgam Hg was determined. Urinary excretion (1), Hg concentration in plasma (2) and absorbed dose (3) were most closely correlated to each other, followed by correlations with the variables of the fillings (4). Correlation coefficients were 0.75 for variables 1 vs 2 and 2 vs 3, and 0.49 for variables 3 vs 4. It was concluded that variables 1-3 best reflected the transfer of mercury from amalgam fillings throughout the organism and that they were relatively insensitive to dietary mercury. The determination of total mercury in plasma and of its urinary excretion rate appears, under practical aspects, most suitable for the investigation of Hg uptake from amalgam.

THE MEASUREMENT AND ANALYSIS OF TRIPLE CORRELATIONS

1964 ◽  
Vol 42 (6) ◽  
pp. 1101-1115 ◽  
Author(s):  
Philip B. Smith
Keyword(s):  
Gamma Rays ◽  
Heavy Particle ◽  
Original Data ◽  
Population Parameters ◽  
True Solution ◽  
Error Matrix ◽  
Mixing Ratios ◽  
Triple Correlation ◽  
Measurement And Analysis

The measurement and analysis of the intensity–direction correlation of gamma rays emitted in cascade following heavy-particle capture are treated. A procedure is discussed which is based upon the expansion of the triple-correlation intensity in terms of the set of angular functions orthogonal over the space of the emission (or absorption) directions. This is in contrast to the usual method which expresses the correlation in terms of Legendre polynomials. In the analysis procedure proposed, the population parameters are found directly from the original data, with the gamma-radiation mixing ratios assigned. The least-squares equations representing the best fit to the data contain the population parameters linearly and are solved by a standard computer program which also gives the value of χ2. The true solution is then found by varying the mixing ratios until a minimum in χ2 is reached. In addition to the determination of the population parameters of the decaying state and the mixing ratios of the gamma rays in the cascade, the calculation of the error matrix of these quantities, and the calculation of the formation parameters in simple capture, are described.

Determination of stable isotope ratios using nuclear reaction analysis coupled with a particle–gamma coincidence method

2021 ◽  
Author(s):  
Paula Rangel Pestana Allegro ◽  
Márcia de Almeida Rizzutto ◽  
Nemitala Added ◽  
Vitor Ângelo Paulino de Aguiar ◽  
Dennis Lozano Toufen ◽  
...  
Keyword(s):  
Nuclear Reaction ◽  
Gamma Rays ◽  
Charged Particles ◽  
Isotope Ratios ◽  
Nuclear Reaction Analysis ◽  
Stable Isotope Ratios ◽  
Coincidence Method ◽  
Medium Energy ◽  
Gamma Coincidence

This study presents an alternative method to determine isotope ratios using a medium energy accelerator and simultaneously measuring the charged particles and gamma-rays produced in a nuclear reaction.

scholarly journals Analysis of the 40K levels in soil using gamma spectrometry

2005 ◽  
Vol 48 (spe2) ◽  
pp. 221-228 ◽  
Author(s):  
José Araújo dos Santos Júnior ◽  
Jorge João Ricardo Ferreira Cardoso ◽  
Cleomacio Miguel da Silva ◽  
Suêldo Vita Silveira ◽  
Romilton dos Santos Amaral
Keyword(s):  
Gamma Spectrometry ◽  
Absorbed Dose ◽  
Soil Samples ◽  
Spectrometry Method ◽  
Dose Rates ◽  
Elemental Concentrations ◽  
High Purity Germanium ◽  
Specific Activities ◽  
Potassium 40

Potassium-40 was determined in soil in an area with 40,000 m² situated in the western State of Pernambuco, Brazil. For radiometric measurements, the gamma spectrometry method with a high purity germanium (HPGe) detector was used. Sampling of 78 soil samples has been performed at intervals of 25 m. The specific activities of 40K were calculated based on the photopeak of 1.46 MeV. Values from 541 to 3,572 Bq kg-1 were obtained (mean of 1,827 Bq kg-1). These values allowed the determination of the elemental concentrations as well as the absorbed dose rates in air, 1 m above the ground. The values varied from 1.7 to 11.5% (mean of 6%) and from 23.4 to 154.3 nGy h-1 (mean of 79 nGy h-1), respectively.

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