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Electrospun ZnO/Bi 2 O 3 /PVA-coated glass samples were fabricated using electrospinning method, with varying ZnO molarities (0 M, 5 M, and 7 M) and Bi 2 O 3 weight percentages (wt%) to assess their potential for x-ray detection and measurement. Sample morphology and elemental composition analysis revealed well-distributed nanofiber strands on the glass substrate, with even dispersion of elements within the nanofiber across all samples. The effective atomic number (Z eff) of the sample is consistently enhanced with the addition of Bi 2 O 3 and higher ZnO molarity, where sample with 7 wt% Bi 2 O 3 own a greater Z eff value (41.56–44.12) than sample with 5 wt% Bi 2 O 3 (37.22–40.54). All samples except Sample A0 and B0 exhibited strong absorbance between wavelength range of 360 nm–400 nm. Sample A0 and B0 yielded energy band gaps (E g) of 2.39 eV and 2.37 eV, respectively, whereby samples with ZnO exhibit energy gaps of E g = 3.29 eV (Sample A1), E g = 3.27 eV (Sample A2), E g = 3.25 eV (Samples B1 and B2). All samples underwent x-ray exposure at various tube voltages (40–60 kVp) to assess their attenuation ability for x-ray detection and measurement. Sample B2 (5 wt% Bi 2 O 3 and 7 M ZnO) exhibited the most favorable linear response, while Sample B1 (5 wt% Bi 2 O 3 and 5 M ZnO) displayed favorable energy dependency. Thus, the electrospun ZnO/Bi 2 O 3 /PVA-coated glass with these compositions are proposed as potential dosimetry material due to their favorable linear response and energy dependency characteristics. • Fabrication of electrospun ZnO/Bi 2 O 3 /PVA-coated glass with varied ZnO molarities and Bi 2 O 3 percentages. • FESEM and EDX analyses show uniform nanofiber distribution and element dispersion. • Electrospun ZnO/Bi 2 O 3 /PVA-coated glass, 5 wt% Bi 2 O 3 , 5 M or 7 M ZnO, collected 4 h, emerges as promising dosimeter. [ABSTRACT FROM AUTHOR]

Organic polymers are light weight, low toxic and environmentally stable candidates of interest in X-ray detection application. But low attenuation and high recombination rate of charge carriers cause low sensitivity is major limitation of these detectors. In this work, organic polymers (PS/PMMA) composites were prepared with high-Z inorganic BiI 3 by simple dry mixing technique. The organic-inorganic hybrid further embedded with conductive carbon filler (MWCNT, CB, GP) to improve the charge collection of the samples. Resistivity and mobility of the samples were studied with help of Hall measurements and mobility-lifetime was calculated by Hecth equation and found (2.1 ± 0.2) × 10−3 cm2V−1. The elemental analysis of the samples had been done by XPS analysis. The X-ray investigations done by using dental X-ray source and the sensitivity of the samples increases from 3.4 to 200 μGy−1 cm−3 by incorporating CB filler with a low leakage current of order of 33.3 pA/cm2. • The composite exhibits a high SNR of 192 with low noise equivalent dose of 1.9 nGy−1 Hz−0.5 • The sensitivity has been increased by 100-fold for hybrid after embedding carbon filler at a low bias of 32V. • A novel solvent free technique to synthesis organic-inorganic hybrid has been used. • The prepared polymer composite has low leakage current density (3.33 pA/cm2) at low bias compared to α-selenium (10 pA/mm2). [ABSTRACT FROM AUTHOR]

Redox-active heteropolyanions are widely applied to redox catalysts and electron acceptors and the understanding of their reduced states in solution is essential. In this study, the structural changes of Keggin-type tungstophosphate: [PW 12 O 40 ]3− induced by electrochemical reduction were investigated using W L 3 -edge X-ray absorption near-edge structure (XANES) spectra in high-energy-resolution fluorescence detection (HERFD) mode. W L 3 -edge HERFD-XANES spectra revealed the changes in the electronic state of W species and local structure of {WO 6 } units, which were negligible in conventional transmittance mode; the peak intensities of the split two white line peaks were switched by the electrochemical reduction accompanied by enlargement of the splitting width. Our findings suggest that the injected electron was delocalized on whole {WO 6 } units in [PW 12 O 40 ]3− and that the improved symmetry of {WO 6 } units compensated for the change in valence due to the injected electron. [ABSTRACT FROM AUTHOR]

The present project will adopt the principle and technology of X-ray imaging to quickly measure the mass thickness (wherein the mass thickness of the item =density of the item × thickness of the item) of the irradiated items and thus to determine whether the packaging size and inside location of the item will meet the requirements for treating thickness upon electron beam irradiation processing. The development of algorithm of X-ray mass thickness detector as well as the prediction of dose distribution have been completed. The development of the algorithm was based on the X-ray attenuation. 4 standard modules, Al sheet, Al ladders, PMMA sheet and PMMA ladders, were selected for the algorithm development. The algorithm was optimized until the error between tested mass thickness and standard mass thickness was less than 5%. Dose distribution of all energy (1–10 MeV) for each mass thickness was obtained using Monte-carlo method and used for the analysis of dose distribution, which provides the information of whether the item will be penetrated or not, as well as the Max. dose, Min. dose and DUR of the whole item. [ABSTRACT FROM AUTHOR]

The Gd 2 O 3 –La 2 O 3 –ZnO–B 2 O 3 –Eu 2 O 3 glasses with different Gd 2 O 3 concentration (Gd:LaZnBEu) were studied in the physical, structural, optical and luminescence properties. The density and refractive index of glass increased with addition of Gd 2 O 3 content. The FTIR spectra demonstrated the BO 3 and BO 4 borate complexes as the main construction in glass those were more disturbed by Gd 2 O 3 increasing. The BO 4 /BO 3 and bridging/non-bridging oxygen ratio, observed from XPS, changed by following the Gd 2 O 3 concentration whose 10 mol% owned the highest values of both ratios. In the absorption spectra, glasses absorbed some photons in UV – NIR region. The excitation by O2−→Eu3+ charge transfer (240 nm), Gd3+→Eu3+ energy transfer (275 nm) and direct Eu3+ excitation (394 nm) caused the strongest Eu3+ photoluminescence at 613 nm (5D 0 →7F 2). The glass with 5 mol%-Gd 2 O 3 , that possessed the optimum Eu3+ local site, exhibited the highest absorbance and photo-/radio-luminescence intensity. The CIE 1931 and UV lamp excitation revealed the strong reddish-orange emission of glasses. The photoluminescence decay time of Eu3+ in glasses were between 1.6 and 2.1 ms and decreased with added Gd 2 O 3 amount. The Gd:LaZnBEu glasses have a potential for LED, laser, display, and X-ray detection devices with integration mode. • The strong luminescence of Eu3+ under different excitations on Eu3+, Gd3+ and charge transfer. • High absorbance and luminescence intensity by the optimum BO 4 /BO 3 and BOs/NBOs ratio in glass. • The strong reddish-orange emission for LED, laser, display and X-ray detection applications. [ABSTRACT FROM AUTHOR]

We developed a two-stage microfluidic reactor consisting of one hot and one cold region to systematically investigate a radiolytic method to synthesize colloidal silver and to improve the sensitivity of radiation dosimeters based on the Ag nanoparticles plasmon intensity. The microfluidic approach avoided growth during the heating stage, resulting in the total absence of a plasmon band for non-irradiated samples, greater control of the particle size distribution, and decreased minimal detectable dose. Doses as low as 0.2 Gy could be detected with sensitivities higher than the reported in the literature. This is a great achievement once most chemical dosimeters, besides 3D gels, are not sensitive to such low doses. Samples prepared in the microreactor and exposed to doses from 0 to 0.75 Gy presented an unexpected absorption band above 500 nm and a fluorescence emission around 380 nm, evidencing the presence of Ag nanoclusters (AgNCs). Both, absorption and emission bands from AgNCs, increase in the 0-0.75 Gy range, suggesting that nucleation predominates in the microreaction stage and in the radiolytic step for doses below 1 Gy. Decreased fluorescence intensity and undetected absorption above 500 nm indicate that growth prevails for doses ≥ 1 Gy. Thus, our work presents a novel way to measure doses based on silver nanoclusters, including both absorption and emission as dosimetric parameters. Besides unveiling nucleation and growth mechanisms associated to nano clusters and particles formation in this radiolytic microreaction, the results put the spotlight on new possibilities for enhanced radiation detection employing AgNCs. [Display omitted] • Two-stage microfluidic reactor leads to decreased minimal detectable dose. • Microreaction results in silver nanoclusters (AgNCs) or nanoparticles (AgNPs). • Ag nanoclusters are formed for irradiation with doses below 0.75 Gy. • Doses as low as 0.2 Gy can be detected with both AgNPs and AgNCs. • AgNPs and AgNCs constitute a new multimodality platform for x-ray detection. [ABSTRACT FROM AUTHOR]

The Gd 2 Y (1-x) Dy x Al 2 Ga 3 O 12 phosphors were prepared by the solid state reaction to study in the structure, photon absorption, photo- and radioluminescence properties. The XRD represented a crystalline cubic with Ia 3 ‾ d space group as the main structure of phosphor. The Y atomic sites were fine replaced by Dy in phosphor structure with Dy content (x) in a range of 0.25–1.00. The grain sizes of phosphor samples observed by SEM were in several micrometers. In the absorption spectra, phosphors absorbed the photons with various wavelengths in UV, VIS and NIR region. Both direct Dy3+ excitation and Gd3+→Dy3+ energy transfer caused the strong photoluminescence (PL) of Dy3+ around 481 (4F 9/2 → 6H 15/2) and 582 (4F 9/2 → 6H 13/2) nm. The PL decay times of phosphors were around 0.10–0.74 ms. Phosphors performed the strong response to X-rays in radioluminescence (RL) spectroscopy which composed of the sharp emission of Dy3+ ion, broad emission of Y-related complex and weak emission of defects. Phosphor with 0.25 Dy content owned the highest PL and RL intensity of Dy3+ due to the concentration quenching effect and appropriate lattice constant, while free-Dy phosphor had the highest RL intensity of Y complexes. The Gd 2 Y 0.75 Dy 0.25 Al 2 Ga 3 O 12 phosphors is a promising material for the X-ray detection applications, especially the X-ray imaging screen. • X-ray detection ability from luminescence of Dy3+ ion and Y-complex. • Photoluminescence of Dy3+ surrounded by high-symmetry environment in phosphor. • Luminescence under the Gd3+ → Dy3+ energy transfer. • The influence of lattice constant on luminescence properties. [ABSTRACT FROM AUTHOR]

The K 2 O–Gd 2 O 3 –B 2 O 3 –P 2 O 5 glass doped with Dy 2 O 3 (Dy:KGPB) were synthesized by the melt-quenching technique. These glasses were subjected to characterize the physical, structure, optical and luminescence properties. It was observed that the density, molar volume and refractive index of glass increased with increasing Dy 2 O 3 concentration. The FTIR result confirmed the main glass network of B O B and P O P linkages those were degraded by adding Dy 2 O 3 modifier. Glasses absorbed photons in ultraviolet, visible light and near-infrared region. The photoluminescence under direct Dy3+ excitation performed the strong emissions at 574 and 482 nm corresponding to 4F 9/2 → 6H 13/2 and 4F 9/2 → 6H 15/2 transition, respectively. The Gd3+ excitation also caused strong emission of Dy3+ by the Gd3+-Dy3+energy transfer. Glass doped with 1.00 mol% of Dy 2 O 3 owned the highest emission intensity due to the concentration quenching. The lifetime of 4F 9/2 level was found to decrease with addition of Dy 2 O 3 content via dipole-diploe interaction between Dy3+ ion. Judd-Ofelt (J-O) intensity parameters were initially calculated and applied to evaluate the radiative parameters such as branching ratios, radiative transition probabilities, and stimulated emission cross-sections. The radioluminescence of glass was also investigated and found the scintillation efficiency around 15.6%, compared to BGO scintillator. The Dy:KGPB glass has an interesting potential for solid-state laser, LED and X-ray detection applications. • The energy transfer phenomenon was observed from Gd3+-Dy3+ ions. • The bright greenish-yellow emission was observed for present glasses. • Energy transfer parameter show increasing trend with increase in Dy3+ ions. • X-rays scintillation efficiency of glass was 15.6% compared to BGO scintillator. • CIE chromaticity diagram show greenish-yellow emission under UV lamp excitation. [ABSTRACT FROM AUTHOR]

Single crystal of Tm-doped LaCl 3 (LaCl 3 :Tm3+) with the dimension of diameter 7 mm and length 55 mm was successfully grown using an in-house-developed Bridgman furnace. The grown crystal has the self-trapped exciton (STE) emission in the range of 300–500 nm along with the characteristic emissions corresponding to the 4f-4f transition of Tm3+ ions under X-ray excitation. The scintillation characterizations of the grown crystal were performed by pulse height spectra, scintillation decay time, as well as pulse shape discrimination studies under γ-ray and α-particle excitation sources. The LaCl 3 :Tm3+ crystal was found to have a high light yield (42,000 ± 4,200 ph/MeV) with 4.2% energy resolution under γ-rays excitation. Moreover, the pulse shape discrimination was studied using 137Cs and 241Am as the radiation sources with a good FOM value. The results conclude the LaCl 3 :Tm3+ single crystal to be a promising candidate for X-ray and γ-ray detection purposes. • The LaCl 3 :Tm3+ crystal was successfully grown by Bridgman technique. • Host STE band and characteristic Tm3+ transition are visible in the XIL studies. • High light yield (41,511 ± 2,906 ph/MeV) with 4.23% energy resolution (137Cs source). • The timing performance of crystal was found to be 3.42 μs (89%) with 137Cs source. • The excellent PSD capability of LaCl 3 :Tm3+ crystal between γ-ray and α-particles. [ABSTRACT FROM AUTHOR]

The glass formula of 20Li 2 O+10AlF 3 +2.5CaF 2 +(66.5- x)P 2 O 5 + x Gd 2 O 3 +1Eu 2 O 3 (PLACEu 1 Gd x), where x = 2,4,6,8,10 mol% have been prepared by conventional melt-quenching technique. These glasses' optical absorption, photoluminescence, decay time, and radioluminescence have been measured at room temperature. Judd-Ofelt's (J-O) analysis of PLACEu 1 Gd 8 has been investigated and the magnitude of parameters follows the trend as Ω 2 >Ω 4 >Ω 6. The important laser parameters such as radiative properties are calculated using J-O parameters and luminescence spectra. The decay time with the transition from the 5D 0 level was estimated under 274 nm and 394 nm excitation using bi-exponential fitting. CIE coordinates, CCT and intensity ratio have been calculated for glass samples. The integral scintillation efficiency of PLACEu 1 Gd 8 is 31% compared with BGO crystal. The PLACEu 1 Gd x glasses are promising for laser medium and x-rays detection material applications. • The effect of Gd 2 O 3 in Li 2 O–AlF 3 –CaF 2 –P 2 O 5 –Eu 2 O 3 glasses was investigated. • The phonon energy was approximate to be 1170.36 cm−1. • The quantum efficiency of PLACEu 1 Gd 8 glass is 97%. • The light yield of the prepared glass was estimated to be 31% of the commercial BGO crystal. • The calculation of CIE, CCT and intensity ratio of these glasses were shown reddish-orange emission. [ABSTRACT FROM AUTHOR]

To improve the characterization of the detection efficiency of a NaI(Tl) scintillation detector in the low energy range, measurements and Monte Carlo simulations were performed with a certified reference material (CRM) and disk sources. The detection efficiency as modeled. In the MCNP simulation, the detection efficiency dropped as expected at 33.17 keV. The X-ray escape correction factors of a 204Tl disk source and MCNP simulations were compared, a factor of the 204Tl was similar. Moreover, Correcting the X-ray escape and using fewer sources than the CRM resulted in better detection efficiency for the NaI(Tl) detector in the low energy range. • An iodine X-ray escape correction factors were calculated using MCNP simulation of a NaI(Tl) scintillation detector. • The summing or overlapped peaks of spectra of disk sources and certified reference material were analyzed. • The iodine X-ray esecape of the detection efficiency in a low energy range was corrected. [ABSTRACT FROM AUTHOR]

Scattered x rays are detrimental to the image quality of x-ray transmission radiography. Anti-scatter grids have been used in diagnostic x-ray imaging to improve the image quality but are not practical to use for megavoltage (MV) x-ray imaging in radiotherapy since a MV grid would be very bulky, heavy, and costly. An inherent anti-scatter detector based on Čerenkov radiation was introduced recently for MV x-ray imaging. The purpose of this work is to investigate experimentally the anti-scatter property of a single pixel prototype detector. The scatter to primary ratio (SPR) has been measured using a linear accelerator with a 6 MV x-ray beam. It has been found that the SPR for the prototype detector is 30–60% less than that of an ionization chamber, depending on the imaging geometry. This indicates the prototype detector is less sensitive to scattered radiation. [ABSTRACT FROM AUTHOR]

The influence of the gas-static processing on the optical, structural and electrophysical properties of Au–CdZnTe–Au structures, used in X- and gamma-ray detectors, was investigated. The processing, which is described in detail in the experimental part, was done in a laboratory-scale setup “GAUS-4/2000-35” with the following process parameters: pressure=0.32±0.02 GPa, temperature ~170 °C, time=2 h. The influence of the mentioned processing on the photoluminescence, the Raman scattering, the electric resistance, the I–V characteristics and the spectrometric parameters of the Au–CdZnTe–Au structures was determined. The physical mechanisms, through which the gas-static processing induces changes in the structural and functional properties, were analyzed. It was observed that the gas-static processing (with the above-mentioned process parameters) of the Au–CdZnTe–Au structures leads to a significant increase of the electric resistance of the structures; it also leads to the increase of the intensity of the photoelectric absorption peak when the respective detector is registering X- and gamma-radiation with energy near 32.19 keV. The Raman and photoluminescence data indicates the formation of the surface oxides TeO x and the compensation of Cd vacancies by Au atoms. The assumption that, under the discussed processing, two different rival processes modify the Au–CdZnTe junction due to the influence of the increased temperature ~170 °C and pressure ~0.3 GPa, was suggested. The first process is the formation of TeO 2 oxide (which increases the electric resistance) on the contact; the second process is the destruction of the surface films of the oxides and the absorbed gases. Most likely, the first process is dominant, which was evidenced by the Raman and photoluminescence measurements. [ABSTRACT FROM AUTHOR]

The physical, structural, optical, shielding, thermal and luminescence properties of WO 3 -Gd 2 O 3 –B 2 O 3 glasses were studied in this work. The effect of WO 3 replacement by Gd 2 O 3 on radiation shielding and radiation detection potential was evaluated. The glass density increases with increasing Gd 2 O 3 concentration and the maximum value is 5.97 g/cm3. The FTIR and XRD result confirm that the trigonal BO 3 , tetrahedral BO 4 and tungsten complex are the main chemical groups and coorperate into the amorphous structure of glass. The optical absorption spectra exhibit the absorbance of glasses in ultraviolet and visible light region. The shielding parameters of glasses, such as mass attenuation coefficient, effective atomic number, electron density and half value layer, were investigated theoretically and experimentally. They perform a small degradation of shielding property by increasing Gd 2 O 3 content. There is no obvious dependence of Gd 2 O 3 concentration on glass thermal conductivity and expansion. The strong photoluminescence of [WO 6 ]6- group with 524 nm occurred under its charge transfer excitation and under the energy transfer from excited Gd3+ ion. In the radioluminescence, WGB glasses emitted the visible light with 562 nm based on the mixed emission from [WO 6 ]6- group and oxygen vacancy. The glass possesses the X-ray detection efficiency around 18.65% of BGO crystal. The WO 3 –Gd 2 O 3 –B 2 O 3 glass with 17.5 and 27.5 mol% of Gd 2 O 3 is a promising γ-ray shielding material at room temperature and high temperature circumstance, respectively and one with 25 mol% of Gd 2 O 3 owns the attractive potential for the X-ray radiation detection applications. • The self-luminescence of WO 3 –Gd 2 O 3 –B 2 O 3 glass. • X-ray detection ability. • High radiation shielding quality compared to shielding concrete and Schott's glass. • High-density glass. [ABSTRACT FROM AUTHOR]

We studied the X-ray spectroscopy capability and the detection efficiency of a low cost Commercial Off The Shelf CMOS Image Sensor (CIS) in the energy range from 6.4 to 24.9 keV using the fluorescence spectra emitted by FeNi, Cu, Zr, Pb, and Ag. The obtained results are compared with that obtained using a Silicon Drift Detector (SDD). We conclude that CIS is able to resolve fluorescence lines up to 17.7 keV but with a reduced detection efficiency. At lower energies, the energy resolution of the CIS is comparable to that obtained with the SDD. By the comparison of both detectors we also estimate the detection efficiency of the proposed method and the effective thickness of the CIS for all the measured X-ray lines. 00-01, 99-00. • The COTS CMOS image sensor (CIS) was able to resolve X-Ray lines up to 17.7 keV. • At lower energies, the energy resolution of the CIS and SDD are comparable. • The detection efficiency of CIS ranges from 5.5% at 6.4 keV to 0.12% at 17.7 keV. • The effective thickness of the CIS for all the measured X-ray lines was estimated. • COTS CMOS image sensors can be used to obtain multiespectral X-ray imaging. [ABSTRACT FROM AUTHOR]

Electronic structures of the temperature-induced valence transition system EuNi 2 (Si 1– x Ge x) 2 with x = 0.70, 0.79, 0.82 have been investigated by means of high-energy resolution fluorescence detection X-ray absorption spectroscopy (HERFD-XAS). The HERFD-XAS spectra clearly change their intensities of Eu2+ and Eu3+ components which directly reflect the temperature-induced valence transition. For x = 0.70, gradual spectral change exhibits a continuous valence transition, while drastic changes for x = 0.79 and 0.82 indicate first-order valence transitions. High-energy resolution measurements made it possible to observe additional fine structures which are recognized more clearly below the transition temperature. Existence of these fine structures suggests that many-body effect plays an important role in the temperature-induced valence transition of this system. The variation of Eu mean valence estimated from the HERFD-XAS spectra for each x correlates with that of magnetic susceptibility. • Valence transition of EuNi 2 (Si 1- x Ge x) 2 proved by means of Eu L 3 HERFD-XAS. • Temperature-dependent fine structures reminiscent of change in many-body interaction through the valence transition. • Variation of Eu valence through the valence transition is associated with that of magnetic states. [ABSTRACT FROM AUTHOR]

Semiconductor sensors are extensively used for X-ray detection, both for spectroscopy and 2D imaging. In this work, the Monte Carlo code PENELOPE v. 2014 with the PenEasy v. 2015 extension was applied for simulating a Medipix3RX detector, including the sensor and the ASIC layers. The code was modified to include the charge dispersion effect modelling at the Pixelated Imaging Detector tally, and validated by investigating the influence of the electric field, incident energy, beam position, pixel size and also by determining the Modulation Transfer Function. The results were compared to experimental data and presented a very good agreement. The Monte Carlo simulation can be used to investigate the detector response and its influence on measured data, such as spatial resolution and X-ray spectra distortion. Besides, the simulation can be applied to determine the energy deposition in each layer of the detector, useful for detection efficiency characterization or radiation damage studies. • Monte Carlo model of a pixel detector. • PENELOPE. • Charge sharing. • Experimental validation. [ABSTRACT FROM AUTHOR]