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In positron annihilation, exploration of the polarization correlations of the emerging gamma quanta has gained interest, since they offer a possibility to improve signal-to-background in medical imaging using positron emission tomography. The annihilation quanta, which are predicted to be in an entangled state, have orthogonal polarizations and this property may be exploited to discriminate them from two uncorrelated gamma photons contributing to the background. Recent experimental studies of polarization correlations of the annihilation quanta after a prior Compton scattering of one of them, had rather different conclusions regarding the strength of the correlation after the scattering, showing its puzzling nature. The scattering was described as a decoherence process. In the present work, we perform for the first time, a study of the polarization correlations of annihilation quanta after decoherence via Compton scattering in the angular range 0 ∘ − 50 ∘ using single-layer gamma ray polarimeters. In addition, we compare the measured polarization correlations after Compton scattering at 30 ∘ with an active and a passive scatterer element. The measured azimuthal correlation of back-to-back annihilation quanta is consistent with the Pryce-Ward formulation, as confirmed by Monte Carlo simulations. Further, the results indicate that the correlation, expressed in terms of the polarimetric modulation factor, shows no significant difference at small scattering angles (0 ∘ − 30 ∘) compared to the correlation measured for direct photons, while a moderate indication of a lower modulation is observed for 50 ∘ scattering angle. The measured modulation is larger at all scattering angles than the one expected from the simulation of orthogonally polarized, independent annihilation quanta. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive investigation of borate-based glasses doped with BaO, assessing their physical, structural, optical, and radiation shielding properties through experimental and theoretical analyses. XRD patterns reveal the amorphous nature of the prepared glass samples. Density and molar volume values, and FTIR spectra indicate the impact of BaO concentration on the glass matrix, affecting structural properties. Thermal analysis via TGA/DSC reveals improved thermal properties with the substitution of B 2 O 3 with BaO. UV–visible absorption spectroscopy shows a decrease in energy band gap with rising BaO content, suggesting potential non-bridging oxygen formation. Mass attenuation coefficient (μ m) values exhibit an exponential decay trend with photon energy, influenced by photoelectric absorption, Compton scattering, and pair creation. The glasses prepared had, in general, a better μ m values compared to that of concretes and other glass compositions containing barium oxide. Experimental and theoretical (XCOM) results for mean free path (MFP) and half-value layer (HVL) demonstrate close agreement, validating the accuracy of the experimental data. Both MFP and HVL increase with energy and decrease with BaO addition, emphasizing the potential for these glasses in radiation shielding applications. • Borate based glass samples of the composition (70-x)B 2 O 3 –20Bi 2 O 3 –5ZnO–5WO 3 -xBaO; x = 0, 5, 10, 15 and 20 mol% have been successfully prepared by melt-quenching process. • The addition of BaO in the glass system improves its density, thermal and gamma radiation shielding properties. • The study elucidates structural modifications of borate glasses imparted by the doping of BaO. • Non-toxic and environmentally friendly nature, along with effective shielding behavior, of our prepared glass samples makes it a practical solution for gamma shielding applications. [ABSTRACT FROM AUTHOR]

In this study, albedo parameters are experimentally measured to determine radiation scattering features of some thermoluminescent dosimetry materials (TLD 100, TLD 100h, TLD 200 and TLD 400). In experimental setup, it was used scattering angle of 168°, 59.54 keV gamma rays and HPGe detector. The effective atomic numbers of the investigated materials were determined from the coherent to Compton scattering intensity ratio. Also, the mass attenuation coefficient, the mass energy absorption coefficient and kerma relative to air and ICRU tissue were calculated for the TLD materials. It was observed that TLD 100h is the best tissue equivalent material among other TLD materials and best reflects 59.54 keV gamma rays. • The effective atomic numbers of some thermoluminescent dosimetry materials were obtained from scattering ratios. • The effective atomic number and albedo parameters are obtained for 59.54 keV photon energy. • TLD 100h is the material that best reflects 59.54 keV gamma rays. [ABSTRACT FROM AUTHOR]

The gamma-radiation shielding capabilities of a Ni 0.2 Mg x Zn 0.8-x Fe 2 O 4 nanocrystal, synthesized using the sol-gel auto-ignition process, were described in the present investigation. The synthesized materials were analyzed using different techniques such as XRD, UV–Vis, FTIR, FE-SEM, and EDS to investigate their structural, optical, and functional group morphological properties, and elemental analysis. Additionally, utilizing various gamma-ray sources and a NaI (Tl) scintillation detector, we investigated the gamma-ray shielding parameters for the prepared materials. The cubic spinel structure of all produced Nanoferrites is clear from X-ray diffractograms, which show no contaminated phases. Pellets of nanocrystalline spinel ferrites have been exposed to gamma radiation from various sources by varying the intensity of the radiation dose. Utilizing Phy-X/PSD Software, a comparative analysis of the mass and linear attenuation coefficients, mean free path, half value layer, tenth value layer, effective atomic number, and effective electron density for synthesized spinel ferrites is performed at 122–1330 keV. Using the geometric progression (G-P) fitting technique, the gamma-ray energy absorption build-up factor (EABF) for four selected ferrites is explored at incident photon energy levels ranging from 0.015 to 15 MeV. It is found that the Compton scattering process is mostly responsible for the EABF maximum in an intermediate region. K1 has a higher EABF value than other ferrites, which is largely determined by the crystallite size effect and the chemical composition of the material. There is a good agreement between the theoretical and experimental results. Among the studied samples, sample K1 and K4 have superior gamma-ray and fast neutron attenuation capabilities respectively than its counterparts. The current study offers a thorough examination of the chosen iron oxides in the context of gamma and neutron radiation. • The values of μ m , μ, Z eff , λ, HVL, TVL were determined experimentally using NaI (Tl) detector. • Experimental results have been supported with Phy-X/PSD Software values. • The energy absorption buildup factor have been calculated using G.P. fitting method. • The values of macroscopic removal cross-sections for neutrons were determined. • Measured data in mixed neutron-gamma radiation field are useful in nuclear medicine application. [ABSTRACT FROM AUTHOR]