ATMOSPHERIC ABSORPTION OF 2.62 MEV GAMMA‐RAY PHOTONS EMITTED FROM THE GROUND

Geophysics ◽  
1975 ◽  
Vol 40 (6) ◽  
pp. 1058-1065 ◽  
Author(s):  
R. L. Grasty
Keyword(s):  
Absorption Coefficient ◽  
Gamma Ray ◽  
Dead Time ◽  
Detector Efficiency ◽  
Aircraft Structure ◽  
Linear Absorption Coefficient ◽  
Linear Absorption ◽  
Electronic Circuitry ◽  
Gamma Ray Spectrometer ◽  
Radioactive Concentration

The actual measured decrease in gamma radiation with altitude, as measured by a gamma‐ray spectrometer, was found to be less than predicted on simple theoretical grounds. The various factors which reduced this apparent absorption were Compton scattering in the ground and in the air, the variation of detector efficiency with angle, the mass of material of the aircraft structure and detector housing below the detectors, the dead‐time of the electronic circuitry, and an increase in ground radioactive concentration with depth. When these effects were incorporated, experimental and theoretical values of the linear absorption coefficient in air for 2.62 Mev photons were found to agree.

Interpretation of total gamma logs in thin and dipping beds

Geophysics ◽  
1980 ◽  
Vol 45 (12) ◽  
pp. 1847-1856
Author(s):  
Donald C. Moore
Keyword(s):  
Gamma Ray ◽  
Mass Attenuation Coefficient ◽  
Integral Function ◽  
Calibration Model ◽  
Linear Absorption Coefficient ◽  
Linear Absorption ◽  
K Factor ◽  
Proportional Relationship ◽  
Dip Angle ◽  
Gamma Ray Log

The proportional relationship between the grade‐thickness product and the area under a gross gamma‐ray log is well known and generally accepted as correct. A set of conditions for its correctness is derived. It is shown that the proportionality factor (K factor) is independent of the dip angle of the bed, because both the thickness of the bed (measured along the borehole) and the area under the gross gamma‐ray log increase in the ratio of the secant of the dip angle. Experimental data supporting this conclusion are presented. It is also shown that the dip angle of a relatively thick bed can be estimated by deconvolving the log near the edge of the bed. Finally, the comparison parameters between a formation and a calibration model are shown to be grade, gamma‐ray mass attenuation coefficient, moisture content, and an integral function of the build‐up factor and the gamma‐ray linear absorption coefficient.

Optical Absorption In Hg1−xCdxTe

1997 ◽  
Vol 484 ◽  
Author(s):  
Vaidya Nathan
Keyword(s):  
Experimental Data ◽  
Optical Absorption ◽  
Band Structure ◽  
Absorption Coefficient ◽  
Numerical Results ◽  
Recent Experimental Data ◽  
Narrow Gap ◽  
Interband Transitions ◽  
Linear Absorption Coefficient ◽  
Linear Absorption

AbstractThe theory of optical absorption due to interband transitions in direct-gap semiconductors is revisited. A new analytical expression for linear absorption coefficient in narrow-gap semiconductors is obtained by including the nonparabolic band structure due to Keldysh and Burstein-Moss shift. Numerical results are obtained for Hg1−xCdxTe for several values of x and temperature, and compared with recent experimental data. The agreement is found to be good.

scholarly journals Determination of the quasi-TE mode (in-plane) graphene linear absorption coefficient via integration with silicon-on-insulator racetrack cavity resonators

2014 ◽  
Vol 22 (15) ◽  
pp. 18625 ◽  
Author(s):  
Iain F Crowe ◽  
Nicholas Clark ◽  
Siham Hussein ◽  
Brian Towlson ◽  
Eric Whittaker ◽  
...  
Keyword(s):  
Absorption Coefficient ◽  
Silicon On Insulator ◽  
Linear Absorption Coefficient ◽  
Linear Absorption ◽  
Cavity Resonators ◽  
Te Mode

scholarly journals Effect of egg white, perlite, gypsum and fly ash in environment friendly insulation materials

2018 ◽  
Vol 16 (3) ◽  
pp. 329-342
Author(s):  
Hanifi Binici ◽  
Orhan Aksogan ◽  
Rifat Resatoglu
Keyword(s):  
Thermal Conductivity ◽  
Fly Ash ◽  
Absorption Coefficient ◽  
Egg White ◽  
Radiation Hazard ◽  
Binding Property ◽  
Insulation Material ◽  
Linear Absorption Coefficient ◽  
Linear Absorption ◽  
Insulation Materials

In this study, engineering features of insulation materials produced from egg white, perlite, gypsum and fly ash were investigated. Densities, water absorption ratios, ultrasonic velocities and thermal conductivity coefficients of samples were determined. Furthermore, linear absorption coefficient were measured by gamma ray saturation levels at 17.7, 26 and 60 keV energies. Thermal conductivity coefficients of the produced composites were found to be in the range 0.0882- 0.0995 Kcal/mh?C. Egg white decreased the linear absorption coefficients. Unit weights of samples were found to be dependent on their contents. As gypsum rate increased, unit weight also increased. As perlite rate increased thermal conductivity coefficient decreased. As egg white decreased the linear absorption coefficient decreased, also. The most important benefits of these types of materials are their being impermeable and perfectly compatible with the environment. These lighter type materials were/are compatible with Turkey and the Middle East environment. Egg white has been resistant to radiation. Hence, it is highly compatible with the environment. The compressive and flexural strengths of mortars decreased with the use of egg whites in mortar. So, egg white enhances the binding property of samples. In most cases, some organic and/or inorganic additives are used as well, to improve the physical and mechanical properties of mortar, such as egg whites and others. Finally, this study shows that it is possible to produce an insulation material resistant to sound and radiation by using egg white, perlite and fly ash. It is seen that the samples incorporating egg white could be used at hospitals, military and industrial facilities and shelters which are under radiation hazard. Furthermore, this insulation materials will be put to use in industry in Turkey after many experiments have been done on laboratory.

Preconditions of Creation of Self-Adhesive Elastic Radiation Shielding Coverings

2019 ◽  
Vol 974 ◽  
pp. 429-434
Author(s):  
D.V. Cherkasov ◽  
V.V. Avdonin ◽  
Y.V. Yurkin
Keyword(s):  
Absorption Coefficient ◽  
High Hardness ◽  
Radiation Shielding ◽  
Linear Absorption Coefficient ◽  
Linear Absorption ◽  
Ethylene Propylene ◽  
Ethylene Propylene Rubber

Results of scientific researches in the field of creation of self-adhesive radiation shielding materials on the basis of polymers are presented in this article. It is stated, that radiation shielding coverings on the basis of ethylene propylene rubber are more preferable than coverings on the basis of BSR and SBS. Materials on the basis of ethylene propylene rubber possess high hardness at scaling from metal (more than 600 N/m) and hardness at breakoff from concrete (more than 0,1 MPa), have a high linear absorption coefficient.

The limit of application of the Scherrer equation

2018 ◽  
Vol 74 (1) ◽  
pp. 54-65 ◽  
Author(s):  
M. A. R. Miranda ◽  
J. M. Sasaki
Keyword(s):  
Absorption Coefficient ◽  
Crystallite Size ◽  
Computer Simulations ◽  
Systematic Study ◽  
Bragg Angle ◽  
Linear Absorption Coefficient ◽  
Linear Absorption ◽  
Maximum Value ◽  
Extinction Length ◽  
Scherrer Equation

The Scherrer equation is a widely used tool to obtain crystallite size from polycrystalline samples. Its limit of applicability has been determined recently, using computer simulations, for a few structures and it was proposed that it is directly dependent on the linear absorption coefficient (μ0) and Bragg angle (θB). In this work, a systematic study of the Scherrer limit is presented, where it is shown that it is equal to approximately 11.9% of the extinction length. It is also shown that absorption imposes a maximum value on it and that this maximum is directly proportional to sin θB/μ0.

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