Gamma particle detection in detector’s interring window (see Fig. 1) and the calculations have been performed with obtained results. Figure 4 denoted the obtained results in simulation for considered weight fractions including counts, attention coefficient, mass attenuation coefficient, half value layer (HVL) and also tenth value layer (TVL).
Error bars used in all Figure are so small (~ 10− 6 order) in which they are under the symbol.
According to the simulation results the gamma attenuation of the considered shield can increase by adding a heavy material such as PbO and can lead to construction for more investigations. Hence, the material has been constructed as mentioned in section 2.2.1 and 5 samples including one pure polyurethane foam were available. Weight fraction change led to several samples, reported in Fig. 7, with 0.2%, 0.5%, 1% and 4% of PbO doped in polyurethane material during synthesis process.
Figure 5 reports SEM results for these samples. Figures shown as A, B and C report the SEM of the polyurethane material plus PbO in scale of 20, 50 and 200 µm, respectively. In addition, figure D and E compare SEMs in scale of 100 µm in which D is polyurethane plus PbO and E represents pure polyurethane.
SEM results reported a visible PbO vision which is required. Dopped PbOs are obvious in figure D. however, PbO is heavy and had a small fraction of the material to reduce the weight of the component. In addition to accessing desired SEM results, samples were tested via XRD for more precise results. XRD results for the constructed shield is reported in Fig. 6.
In which the blue curve represents the pure material of PUF and red curve is the PbO dopped sample. The PbO peaks appearing in the sample curve prove the accuracy of the SEM results.
In addition to simulation results, samples have been irradiated in experimental set up shown in Fig. 7 as similar as possible to simulated set up (see Fig. 1).
Figure 8 reports radiation shielding properties of constructed shields including counts per second, attenuation, mass attenuation coefficient, HVL and TVL results.
The experiment was performed three times for each sample in 30 seconds and the average value has been utilized in these calculations. All samples were successful in attenuating the radiation, however, as it can be predicted, increasing the PbOs weight fraction can cause more shielding property. And the sample with 4% PbO has more resistance against gamma radiation.