Abstract
The thermal neutron diffusion cooling coefficient is a macroscopic material parameter. It is needed for description of the decay of the thermal neutron pulse in a medium and gives information of the diffusion cooling of the thermal neutron spectrum in a bounded volume. Experimental results from various measurements for plexiglass are overviewed in the paper. A method for theoretical, exact calculation of the parameter is presented. The formula utilizes some other thermal neutron parameters and a cooling function, i.e. the function which describes the deviation of the neutron spectrum in a bounded system from the distribution in an infinite one. The energy dependence of the function is obtained numerically from relations which results from the eigenvalue problem of the scattering operator when both the decay constant and the spectrum of the thermal neutron flux are developed on powers of the geometrical buckling. The case of a 1/{nu} absorption cross section is considered. The calculation utilizes a synthetic scattering function elaborated for hydrogenous media by GRANADA (1985). The influence of some quantities used in the calculation on the final result is investigated. The obtained value of the diffusion cooling coefficient for plexiglass is C = 6514 cm{sup 4}s{sup -1} at the
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Citation Formats
Drozdowicz, K.
Thermal neutron diffusion cooling coefficient for plexiglass.
Sweden: N. p.,
1992.
Web.
Drozdowicz, K.
Thermal neutron diffusion cooling coefficient for plexiglass.
Sweden.
Drozdowicz, K.
1992.
"Thermal neutron diffusion cooling coefficient for plexiglass."
Sweden.
@misc{etde_10135717,
title = {Thermal neutron diffusion cooling coefficient for plexiglass}
author = {Drozdowicz, K}
abstractNote = {The thermal neutron diffusion cooling coefficient is a macroscopic material parameter. It is needed for description of the decay of the thermal neutron pulse in a medium and gives information of the diffusion cooling of the thermal neutron spectrum in a bounded volume. Experimental results from various measurements for plexiglass are overviewed in the paper. A method for theoretical, exact calculation of the parameter is presented. The formula utilizes some other thermal neutron parameters and a cooling function, i.e. the function which describes the deviation of the neutron spectrum in a bounded system from the distribution in an infinite one. The energy dependence of the function is obtained numerically from relations which results from the eigenvalue problem of the scattering operator when both the decay constant and the spectrum of the thermal neutron flux are developed on powers of the geometrical buckling. The case of a 1/{nu} absorption cross section is considered. The calculation utilizes a synthetic scattering function elaborated for hydrogenous media by GRANADA (1985). The influence of some quantities used in the calculation on the final result is investigated. The obtained value of the diffusion cooling coefficient for plexiglass is C = 6514 cm{sup 4}s{sup -1} at the temperature of 20 degrees C. The uncertainty is estimated to be {+-} 100 cm{sup 4}s{sup -1} within the physical model of the scattering kernel used. (au).}
place = {Sweden}
year = {1992}
month = {Aug}
}
title = {Thermal neutron diffusion cooling coefficient for plexiglass}
author = {Drozdowicz, K}
abstractNote = {The thermal neutron diffusion cooling coefficient is a macroscopic material parameter. It is needed for description of the decay of the thermal neutron pulse in a medium and gives information of the diffusion cooling of the thermal neutron spectrum in a bounded volume. Experimental results from various measurements for plexiglass are overviewed in the paper. A method for theoretical, exact calculation of the parameter is presented. The formula utilizes some other thermal neutron parameters and a cooling function, i.e. the function which describes the deviation of the neutron spectrum in a bounded system from the distribution in an infinite one. The energy dependence of the function is obtained numerically from relations which results from the eigenvalue problem of the scattering operator when both the decay constant and the spectrum of the thermal neutron flux are developed on powers of the geometrical buckling. The case of a 1/{nu} absorption cross section is considered. The calculation utilizes a synthetic scattering function elaborated for hydrogenous media by GRANADA (1985). The influence of some quantities used in the calculation on the final result is investigated. The obtained value of the diffusion cooling coefficient for plexiglass is C = 6514 cm{sup 4}s{sup -1} at the temperature of 20 degrees C. The uncertainty is estimated to be {+-} 100 cm{sup 4}s{sup -1} within the physical model of the scattering kernel used. (au).}
place = {Sweden}
year = {1992}
month = {Aug}
}