Abstract:
The aim of this work is to study the behavior of attenuation coefficient for gamma
rays under thermal non-equilibrium statistical conditions. To do this, 18 samples
from Al, Fe, and Cu were prepared. Six samples from each material were prepared
in the form of pellets. First, samples from Al, Fe, and Cu left without being
exposed to heat, and after that the samples are heated to (24, 40, 50, 60, and 70)0C,
then exposed to gamma radiation. The thickness of each mineral were changed to
be (5, 10, 15, 20, 25, and 30) mm for Al, (4, 8, 12, 16, 20, and 24) mm for Fe, and
(3, 6, 9, 12, 15, and 18) mm for Cu, and they also exposed to gamma rays. The
transmitted beam intensity was measured using GM counter. To see the effect of
heating in evaporating gases and light elements FTIR spectrometer was used.
Copper and Iron samples analyzed by X-Ray Fluorescence (XRF) and we found
that the sample of iron contains (99% of Fe and 1% Ti), and the sample of Copper
contains (61% Cu, 31% Zn, 5%Pb, and 3% Fe)
The results obtained shows that the transmitted intensity in general decreases upon
increasing both temperature and thickness. These two effects are related to thermal
collision and thermal expansion which changes thickness. The temperature
increase and heat flow are related to non-thermal equilibrium and entropy increase.
The non-thermal equilibrium is described by non-equilibrium statistical laws.
The empirical relations of these effects can be easily described using nonequilibrium
statistical laws derived from plasma and quantum laws for resistive
media. These laws describe non-thermal equilibrium statistical states and are
related to entropy and thermal internal heat energy. The attenuation coefficient
increases first with temperature then shows gentle decrease. The initial increase
may result from the fact that initial heating evaporate light elements, which causes
the density to increase. This evaporation results from thermal agitation and the heat
energy thermal mass transfer. Further heating cause samples to expand, thus
increasing its volume which decreases the density. The expansion results from
increase of thermal vibration rate which increases amplitude. Thus the attenuation
coefficient decreases. The increase of thickness decreases attenuation coefficient
which may be related to the re emission process, in which atomic nuclei emit rays.
Thus the decrease of attenuation coefficient can be described by non-equilibrium
statistical laws.
