Fabrication luminescence and radiation shielding properties of Gd2O3–La2O3–ZnO–B2O3–Sm2O3 glasses

arXiv preprint arXiv:2402.15122

Elastic scattering off nuclei in target detectors, involving interactions with dark matter and coherent elastic neutrino nuclear recoil (CENS), results in the deposition of low energy within the nuclei, dissipating rapidly through a combination of heat and ionization. The primary energy loss mechanism for nuclear recoil is heat, leading to consistently smaller measurable scintillation signals compared to electron recoils of the same energy. The nuclear recoil quenching factor (QF), representing the ratio of scintillation light yield produced by nuclear recoil to that of electron recoil at the same energy, is a critical parameter for understanding dark matter and neutrino interactions with nuclei. The low energy QF of NaI(Tl) crystals, commonly employed in dark matter searches and CENS measurements, is of substantial importance. Previous low energy QF measurements were constrained by contamination from photomultiplier tube (PMT)-induced noise, resulting in an observed light yield of approximately 15 photoelectrons per keVee (kilo-electron-volt electron-equivalent energy) and nuclear recoil energy above 5 keVnr (kilo-electron-volt nuclear recoil energy). Through enhanced crystal encapsulation, an increased light yield of around 26 photoelectrons per keVee is achieved. This improvement enables the measurement of the nuclear recoil QF for sodium nuclei at an energy of 3.8 0.6 keVnr with a QF of 11.2 1.7%. Furthermore, a reevaluation of previously reported QF results is conducted, incorporating enhancements in low energy events based on waveform simulation. The outcomes are generally consistent with various recent QF measurements for …

arXiv preprint arXiv:2402.15122

Elastic scattering off nuclei in target detectors, involving interactions with dark matter and coherent elastic neutrino nuclear recoil (CENS), results in the deposition of low energy within the nuclei, dissipating rapidly through a combination of heat and ionization. The primary energy loss mechanism for nuclear recoil is heat, leading to consistently smaller measurable scintillation signals compared to electron recoils of the same energy. The nuclear recoil quenching factor (QF), representing the ratio of scintillation light yield produced by nuclear recoil to that of electron recoil at the same energy, is a critical parameter for understanding dark matter and neutrino interactions with nuclei. The low energy QF of NaI(Tl) crystals, commonly employed in dark matter searches and CENS measurements, is of substantial importance. Previous low energy QF measurements were constrained by contamination from photomultiplier tube (PMT)-induced noise, resulting in an observed light yield of approximately 15 photoelectrons per keVee (kilo-electron-volt electron-equivalent energy) and nuclear recoil energy above 5 keVnr (kilo-electron-volt nuclear recoil energy). Through enhanced crystal encapsulation, an increased light yield of around 26 photoelectrons per keVee is achieved. This improvement enables the measurement of the nuclear recoil QF for sodium nuclei at an energy of 3.8 0.6 keVnr with a QF of 11.2 1.7%. Furthermore, a reevaluation of previously reported QF results is conducted, incorporating enhancements in low energy events based on waveform simulation. The outcomes are generally consistent with various recent QF measurements for …

Astroparticle Physics

COSINE-100 is a dark matter direct detection experiment with 106 kg NaI (Tl) as the target material. 210 Pb and daughter isotopes are a dominant background in the WIMP region of interest and are detected via β decay and α decay. Analysis of the α channel complements the background model as observed in the β/γ channel. We present the measurement of the quenching factors and Monte Carlo simulation results and activity quantification of the α decay components of the COSINE-100 NaI (Tl) crystals. The data strongly indicate that the α decays probabilistically undergo two possible quenching factors but require further investigation. The fitted results are consistent with independent measurements and improve the overall understanding of the COSINE-100 backgrounds. Furthermore, the half-life of 216 Po has been measured to be 143. 4±1. 2 ms, which is consistent with and more precise than most current …

Astroparticle Physics

COSINE-100 is a dark matter direct detection experiment with 106 kg NaI (Tl) as the target material. 210 Pb and daughter isotopes are a dominant background in the WIMP region of interest and are detected via β decay and α decay. Analysis of the α channel complements the background model as observed in the β/γ channel. We present the measurement of the quenching factors and Monte Carlo simulation results and activity quantification of the α decay components of the COSINE-100 NaI (Tl) crystals. The data strongly indicate that the α decays probabilistically undergo two possible quenching factors but require further investigation. The fitted results are consistent with independent measurements and improve the overall understanding of the COSINE-100 backgrounds. Furthermore, the half-life of 216 Po has been measured to be 143. 4±1. 2 ms, which is consistent with and more precise than most current …

arXiv preprint arXiv:2401.07462

We present a comprehensive study of the nonproportionality of NaI(Tl) scintillation detectors within the context of dark matter search experiments. Our investigation, which integrates COSINE-100 data with supplementary spectroscopy, measures light yields across diverse energy levels from full-energy peaks produced by the decays of various isotopes. These peaks of interest were produced by decays supported by both long and short-lived isotopes. Analyzing peaks from decays supported only by short-lived isotopes presented a unique challenge due to their limited statistics and overlapping energies, which was overcome by long-term data collection and a time-dependent analysis. A key achievement is the direct measurement of the 0.87 keV light yield, resulting from the cascade following electron capture decay of Na from internal contamination. This measurement, previously accessible only indirectly, deepens our understanding of NaI(Tl) scintillator behavior in the region of interest for dark matter searches. This study holds substantial implications for background modeling and the interpretation of dark matter signals in NaI(Tl) experiments.

arXiv preprint arXiv:2401.07462

We present a comprehensive study of the nonproportionality of NaI(Tl) scintillation detectors within the context of dark matter search experiments. Our investigation, which integrates COSINE-100 data with supplementary spectroscopy, measures light yields across diverse energy levels from full-energy peaks produced by the decays of various isotopes. These peaks of interest were produced by decays supported by both long and short-lived isotopes. Analyzing peaks from decays supported only by short-lived isotopes presented a unique challenge due to their limited statistics and overlapping energies, which was overcome by long-term data collection and a time-dependent analysis. A key achievement is the direct measurement of the 0.87 keV light yield, resulting from the cascade following electron capture decay of Na from internal contamination. This measurement, previously accessible only indirectly, deepens our understanding of NaI(Tl) scintillator behavior in the region of interest for dark matter searches. This study holds substantial implications for background modeling and the interpretation of dark matter signals in NaI(Tl) experiments.

arXiv preprint arXiv:2401.07476

We report a study on the background of the Advanced Molybdenum-Based Rare process Experiment (AMoRE), a search for neutrinoless double beta decay (\znbb) of Mo. The pilot stage of the experiment was conducted using 1.9 kg of \CAMOO~ crystals at the Yangyang Underground Laboratory, South Korea, from 2015 to 2018. We compared the measured energy spectra in three experimental configurations with the results of Monte Carlo simulations and identified the background sources in each configuration. We replaced several detector components and enhanced the neutron shielding to lower the background level between configurations. A limit on the half-life of decay of Mo was found at years at 90\% confidence level, based on the measured background and its modeling. Further reduction of the background rate in the AMoRE-I and AMoRE-II are discussed.

arXiv preprint arXiv:2401.07476

We report a study on the background of the Advanced Molybdenum-Based Rare process Experiment (AMoRE), a search for neutrinoless double beta decay (\znbb) of Mo. The pilot stage of the experiment was conducted using 1.9 kg of \CAMOO~ crystals at the Yangyang Underground Laboratory, South Korea, from 2015 to 2018. We compared the measured energy spectra in three experimental configurations with the results of Monte Carlo simulations and identified the background sources in each configuration. We replaced several detector components and enhanced the neutron shielding to lower the background level between configurations. A limit on the half-life of decay of Mo was found at years at 90\% confidence level, based on the measured background and its modeling. Further reduction of the background rate in the AMoRE-I and AMoRE-II are discussed.

Radiation Physics and Chemistry

This work investigates the physical, structural, optical, photoluminescence, and X-ray luminescence properties of Gd1.5MoB2O9: 0.5CeF3 mixed 10ZnO:35BaO:55B2O3 glass with a weight ratio of 1:9. The samples were prepared by heating with microwave synthesis technique varying the time from 5 min to 10 min. The structural studies were analysed using X-ray diffraction analysis (XRD) and the oxidation of cerium atom were analysed using X-ray analysis near edge spectra (XANES). An X-ray diffraction analysis to investigate the structure of samples using by a Shimadzu XRD–6100 diffractometer. XANES spectra of the Ce-LIII edge for samples show peaks at ∼ 5728 eV, confirming the presence of Ce3+ ion and Ce4+ion. A UV-VIS-NIR spectrophotometer was used to record the absorption spectra (Shimadzu, 3600) in the 200–1000 nm wavelength. The photoluminescence of the sample show overlapping …

Physical Review D

We present results from a search for solar bosonic dark matter using the annual modulation method with the COSINE-100 experiment. The results were interpreted considering three dark sector bosons models: solar dark photons, Dine-Fischler-Srednicki-Zhitnisky (DFSZ) and Kim-Shifman-Vainshtein-Zakharov (KSVZ) solar axions, and Kaluza-Klein solar axions. No modulation signal compatible with the expected from the models was found from a dataset of 2.82 yr, using 61.3 kg of NaI (Tl) crystals. Therefore, we set a 90% confidence level upper limits for each of the three models studied. For the solar dark photon model, the most stringent mixing parameter upper limit is 1.61× 10− 14 for dark photons with a mass of 215 eV. For the DFSZ and KSVZ solar axion, and the Kaluza-Klein axion models, the upper limits exclude axion-electron couplings, g a e, above 1.61× 10− 11 for axion mass below 0.2 keV; and axion …

arXiv preprint arXiv:2312.07957

The scintillation characteristics of an undoped CsI crystal with dimensions of 5.8 mm 5.9 mm 7.0 mm, corresponding to a weight of 1.0 g, were studied by directly coupling two silicon photomultipliers (SiPMs) over a temperature range from room temperature (300 K) to a low temperature of 86 K. The scintillation decay time and light output were measured using x-ray (23 keV) and gamma-ray (88 keV) peaks from a Cd radioactive source. An increase in decay time was observed as the temperature decreased from room temperature to 86 K, ranging from 76 ns to 605 ns. Correspondingly, the light output increased as well, reaching 37.9 1.5 photoelectrons per keV electron-equivalent at 86 K, which is approximately 18 times higher than the light yield at room temperature. Leveraging the significantly enhanced scintillation light output of the undpoed CsI crystal at the low temperature, coupling it with SiPMs makes it a promising candidate for the future dark matter search detector, benefiting from the low threshold owing to the high light output. The odd proton numbers from both cesium and iodine provide an advantage for the WIMP-proton spin-dependent interaction. We evaluated the sensitivity of low-mass dark matter on WIMP-proton spin-dependent interaction with the Migdal process, assuming 200 kg of undoped CsI crystals for the dark matter search. We conclude that undoped CsI crystal detectors exhibit world-competitive sensitivities for low-mass dark matter detection, particularly for the WIMP-proton spin-dependent interaction.

arXiv preprint arXiv:2312.07957

The scintillation characteristics of an undoped CsI crystal with dimensions of 5.8 mm 5.9 mm 7.0 mm, corresponding to a weight of 1.0 g, were studied by directly coupling two silicon photomultipliers (SiPMs) over a temperature range from room temperature (300 K) to a low temperature of 86 K. The scintillation decay time and light output were measured using x-ray (23 keV) and gamma-ray (88 keV) peaks from a Cd radioactive source. An increase in decay time was observed as the temperature decreased from room temperature to 86 K, ranging from 76 ns to 605 ns. Correspondingly, the light output increased as well, reaching 37.9 1.5 photoelectrons per keV electron-equivalent at 86 K, which is approximately 18 times higher than the light yield at room temperature. Leveraging the significantly enhanced scintillation light output of the undpoed CsI crystal at the low temperature, coupling it with SiPMs makes it a promising candidate for the future dark matter search detector, benefiting from the low threshold owing to the high light output. The odd proton numbers from both cesium and iodine provide an advantage for the WIMP-proton spin-dependent interaction. We evaluated the sensitivity of low-mass dark matter on WIMP-proton spin-dependent interaction with the Migdal process, assuming 200 kg of undoped CsI crystals for the dark matter search. We conclude that undoped CsI crystal detectors exhibit world-competitive sensitivities for low-mass dark matter detection, particularly for the WIMP-proton spin-dependent interaction.

Physical Review C

The measurement of direct photons from Au+ Au collisions at s N N= 39 and 62.4 GeV in the transverse-momentum range 0.4< p T< 3 Gev/c is presented by the PHENIX collaboration at the BNLRelativistic Heavy Ion Collider. A significant direct-photon yield is observed in both collision systems. A universal scaling is observed when the direct-photon p T spectra for different center-of-mass energies and for different centrality selections at s N N= 62.4 GeV is scaled with (d N ch/d η) α for α= 1.21±0.04. This scaling also holds true for direct-photon spectra from Au+ Au collisions at s N N= 200 GeV measured earlier by PHENIX, as well as the spectra from Pb+ Pb at s N N= 2760 GeV published by ALICE. The scaling power α seems to be independent of p T, center of mass energy, and collision centrality. The spectra from different collision energies have a similar shape up to p T of 2 Gev/c. The spectra have a local inverse …

Physical Review D

We report the results of a search for inelastic scattering of weakly interacting massive particles (WIMPs) off I 127 nuclei using NaI (Tl) crystals with a data exposure of 97.7 kg· years from the COSINE-100 experiment. The signature of inelastic WIMP− I 127 scattering is a nuclear recoil accompanied by a 57.6 keV γ-ray from the prompt deexcitation, producing a more energetic signal compared to the typical WIMP nuclear recoil signal. We found no evidence for this inelastic scattering signature and set a 90% confidence level upper limit on the WIMP-proton spin-dependent, inelastic scattering cross section of 1.2× 10− 37 cm 2 at the WIMP mass 500 GeV/c 2.

Journal of Biosystems Engineering

In order to solve the shortage of roughage supply for dairy farm in Korea, winter cereal forage production after harvesting of rice in the fallow paddy field was studied. Two parts are already reported at the previous paper-One was the model development of the mechanized production, and the other was the study of feasibility of the model and its desirable direction in Korea. In this study, the model system is applied for a winter cereal wrap silage production model to practice in Kyungbook National University farm on 3ha scale for 3 years. Results of the research are summarized as followsIt takes 2 or 3 working days to process the wrap silage in middle of May in Daegu region. Also, not much particular problem can be found during the application test of mechanized wrap silage production.

Radiation Physics and Chemistry

The Gd2O3–La2O3–ZnO–B2O3–Eu2O3 glasses with different Gd2O3 concentration (Gd:LaZnBEu) were studied in the physical, structural, optical and luminescence properties. The density and refractive index of glass increased with addition of Gd2O3 content. The FTIR spectra demonstrated the BO3 and BO4 borate complexes as the main construction in glass those were more disturbed by Gd2O3 increasing. The BO4/BO3 and bridging/non-bridging oxygen ratio, observed from XPS, changed by following the Gd2O3 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 (5D0→7F2). The glass with 5 mol%-Gd2O3, that possessed …

Radiation Physics and Chemistry

This work investigates the physical, structural, optical, photoluminescence, and X-ray luminescence properties of Gd1.5MoB2O9: 0.5CeF3 mixed 10ZnO:35BaO:55B2O3 glass with a weight ratio of 1:9. The samples were prepared by heating with microwave synthesis technique varying the time from 5 min to 10 min. The structural studies were analysed using X-ray diffraction analysis (XRD) and the oxidation of cerium atom were analysed using X-ray analysis near edge spectra (XANES). An X-ray diffraction analysis to investigate the structure of samples using by a Shimadzu XRD–6100 diffractometer. XANES spectra of the Ce-LIII edge for samples show peaks at ∼ 5728 eV, confirming the presence of Ce3+ ion and Ce4+ion. A UV-VIS-NIR spectrophotometer was used to record the absorption spectra (Shimadzu, 3600) in the 200–1000 nm wavelength. The photoluminescence of the sample show overlapping …

Physical Review D

We report the results of a search for inelastic scattering of weakly interacting massive particles (WIMPs) off I 127 nuclei using NaI (Tl) crystals with a data exposure of 97.7 kg· years from the COSINE-100 experiment. The signature of inelastic WIMP− I 127 scattering is a nuclear recoil accompanied by a 57.6 keV γ-ray from the prompt deexcitation, producing a more energetic signal compared to the typical WIMP nuclear recoil signal. We found no evidence for this inelastic scattering signature and set a 90% confidence level upper limit on the WIMP-proton spin-dependent, inelastic scattering cross section of 1.2× 10− 37 cm 2 at the WIMP mass 500 GeV/c 2.

Physical Review D

We report the results of a search for inelastic scattering of weakly interacting massive particles (WIMPs) off I 127 nuclei using NaI (Tl) crystals with a data exposure of 97.7 kg· years from the COSINE-100 experiment. The signature of inelastic WIMP− I 127 scattering is a nuclear recoil accompanied by a 57.6 keV γ-ray from the prompt deexcitation, producing a more energetic signal compared to the typical WIMP nuclear recoil signal. We found no evidence for this inelastic scattering signature and set a 90% confidence level upper limit on the WIMP-proton spin-dependent, inelastic scattering cross section of 1.2× 10− 37 cm 2 at the WIMP mass 500 GeV/c 2.

Radiation Physics and Chemistry

77Br (T1/2 = 57 h) is an important auger electron emitter used in internal radiotherapy. For the cyclotron production of 77Br, the charged particle induced reactions namely 75As(α,2n)77Br, 77Se(p,n)77Br, 78Se(p,2n)77Br, and 80Se(p,4n)77Br were critically evaluated. Literature experimental data were normalized according to the modern standard of the decay data and monitor reactions. Three nuclear model codes (EMPIRE 3.2, TALYS 1.9, and ALICE-IPPE) were used to check the consistency and reliability of the experimental data. For each production route and corresponding radioisotopic impurity (76Br), a well-developed evaluation methodology was employed to generate the statistically fitted recommended excitation function. The recommended excitation functions were then employed to calculate the integral yield. After a comparative analysis on the basis of product yield, level of radioisotopic impurities; the …

Radiation Physics and Chemistry

I-131 is a radioisotope widely used in nuclear medicine for the treatment of pathologies such as thyroid cancer or hyperthyroidism. When I-131 is ingested, it rapidly accumulates in the thyroid gland, emitting radiation that affects the targeted thyroid tissue while also impacting other organs. To ensure patients receive the appropriate dose for desired therapeutic outcomes while minimizing the risk of adverse effects, accurate estimations of absorbed doses after the treatment is crucial. This study focuses on evaluating organ doses following I-131 pill administration. It leverages the recent High-Resolution Anthropomorphic Computational Phantom distributed by the International Commission on Radiological Protection (ICRP), known as the Mesh Type Reference Computational Phantom. Additionally, a biokinetic analysis of iodine is conducted using a Matlab-developed tool based on the ICRP compartment model for …

Radiation Physics and Chemistry

The metal-oxide semiconductor-based structures are among the most prominent optoelectronic devices that can be used in several application fields. The performance of these structures is strongly dependent on the local radiation dose. In this study, we examined the sample structures with and without radiation. The electrical parameters of the studied samples such as ideality factor, series resistance, saturation current, barrier height, and zero-bias barrier height were obtained by performing the forward bias I–V data analyses. The values of n indicate that the irradiation emission mechanism is dominated. Also, this value depends on the evaluation method of the device. According to the Cheung method, while the ideality factor was found to be 5.72 before irradiation, it was found to be 7.04 after irradiation with 30 kGy. According to the TE method, on the other hand, the value of the ideality factor was found to be 6.337 …

Radiation Physics and Chemistry

77Br (T1/2 = 57 h) is an important auger electron emitter used in internal radiotherapy. For the cyclotron production of 77Br, the charged particle induced reactions namely 75As(α,2n)77Br, 77Se(p,n)77Br, 78Se(p,2n)77Br, and 80Se(p,4n)77Br were critically evaluated. Literature experimental data were normalized according to the modern standard of the decay data and monitor reactions. Three nuclear model codes (EMPIRE 3.2, TALYS 1.9, and ALICE-IPPE) were used to check the consistency and reliability of the experimental data. For each production route and corresponding radioisotopic impurity (76Br), a well-developed evaluation methodology was employed to generate the statistically fitted recommended excitation function. The recommended excitation functions were then employed to calculate the integral yield. After a comparative analysis on the basis of product yield, level of radioisotopic impurities; the …

Radiation Physics and Chemistry

In this work, multiferroic BiNi0.1Fe0.9O3 nanoparticles (NPs) has been fabricated by Sol-gel process, then six nanocomposities (NCs) sheets of PVC/x (BiNi0.1Fe0.9O3): x = 0.0, 0.5, 1.0, 3.0, 5.0, and 10.0 wt% were produced by means of the solution casting process. The produced sheets coded as pure PVC, PVC/0.5(BiNiFeO3), PVC/1.0(BiNiFeO3), PVC/3.0(BiNiFeO3), PVC/5.0(BiNiFeO3), and PVC/10.0(BiNiFeO3). X-ray diffraction (XRD), physical, dielectric properties, and γ-ray attenuation capacity have been investigated. The dielectric properties of the investigated NCs sheets were tested at 1 V with a range of frequencies from 50 Hz to 5 MHz. The Phy-X/PSD software used to calculate γ-ray shielding parameters. The density (ρ) of the prepared NCs sheets increased from 1.4051 ± 0.0001 g/cm3 to 3.2650 ± 0.0001 g/cm3. Up to 0.5 wt%, the actual part of permittivity decreased as the concentration of BiNiFeO3 …

Radiation Physics and Chemistry

The number of the Computed Tomography (CT) examinations has increased greatly over the past decade; This has made CT doses the largest source of the individual effective dose from medical exposures worldwide. Evaluation of image quality in CT is an important issue to ensure diagnostic accuracy, while keeping the radiation dose especially to the pediatric patient as low as reasonably possible. The purpose of this study was to assess the physical and psychophysical image quality in pediatric CT for different iterative reconstruction (IR) algorithms. The image quality was measured on each CT system using pediatric QRM abdomen and thorax phantoms for clinical thorax and abdomen examination scanning parameters and using the Catphan 600 phantom for head examination scanning parameters. The performance of each CT systems was evaluated individually using conventional filtered back-projection …

Radiation Physics and Chemistry

Mortars stand among the very few materials that theoretically cannot be reused due to irreversible hardening processes. Among the various dating techniques, radiocarbon and Optically Stimulated Luminescence (OSL) struggle for being selected as the most robust and reliable dating technique for the specific material. The principle of mortar OSL dating depends on the bleaching of the quartz grains of the sandy aggregate while mixing and laying the mortar to daylight. Thus, the OSL ages strongly depend on the effective bleaching of the quartz. Here, we deal with OSL ages from the old Roman Theatre of Padua. Preliminary OSL results based on Single Aliquot Regeneration (SAR) protocol using three regenerated doses to multigrain (MG) quartz aliquots, indicated distributions of ED (Equivalent Dose) leading to significant mismatch of these results compared to the expected ages. The present work attempts to …

Radiation Physics and Chemistry

Monitoring the level of radioactive contamination and the type of radiation in the environment is very important for the protection of facilities, employees, and people. Phoswich detector is one of the useful tools to identify different radiations and separate them from each other using different scintillating crystals. However, their design can be very diverse based on the type of particles analyzed and various parameters of scintillating crystals and needs optimization to have maximum efficiency. This work aims to optimize the scintillating crystal layers for the design of the three-layer alpha-beta-gamma phoswich detector based on Monte Carlo radiation transport calculations. The selection of the appropriate model for the type and thickness of each layer is based on the optimization of parameters such as energy accumulation, produced scintillation optical photons, attenuation of optical photons, and scintillation decay time …

Radiation Physics and Chemistry

The authors would like to add the following acknowledgments to the two following projects: project PID2021-123100NB-I00 funded by MCIN/AEI/10.13039/501100011033/FEDER, UE, and project PCI2022-135037-2 funded by MCIN/AEI/10.13039/501100011033/and European Union NextGenerationEU/PRTR.The authors would like to have the following acknowledgments: This work was supported in part by the I+ D+ i grant PGC2018-096717-B-C21 funded by MCIN/AEI/10.13039/501100011033, by project PID2021-123100NB-I00 funded by MCIN/AEI/10.13039/501100011033/FEDER, UE, by project PCI2022-135037-2 funded by MCIN/AEI/10.13039/501100011033/and European Union NextGenerationEU/PRTR, by the European Commission H2020 Framework Programme project SANDA (Grant agreement ID: 847552) and by funding agencies of the n_TOF participating institutions.

Radiation Physics and Chemistry

This study aims to develop a software for measuring the computed tomography (CT) number of multiple materials automatically and investigate the impact of tube voltage on the measured CT numbers. The software was specifically design to automatically measure CT number of multiple materials on images of an ACR 464 CT phantom (Gammex, Inc.). Automatic measurements were performed using the matching technique based on the centroids of the phantom and bone objects. The software was tested first on images of the phantom scanned using a GE Revolution EVO 128-slice with rotation variations from 1° to 10° to evaluate its accuracy against rotation. The software was then implemented on images of the phantom scanned with tube voltage variations of 80, 100, 120, and 140 kV. Results of automatic measurements were compared with manual measurements. Manual measurements were performed using a …

Radiation Physics and Chemistry

This research uses co-precipitation to synthesize cobalt nickel ferrite as a heavy metal absorbing material from natural iron sand. The co-precipitation method was applied with temperature calcination of 700 °C for 2 h. Characterization of crystal structure using X-ray diffraction (XRD), characterization of magnetic properties using Vibrating Sample Magnetometer (VSM), and characterization of particle morphology using Field Emission Scanning Electron Microscopes (FE-SEM). Characterization of adsorption capacity of samples using Atomic Absorption Spectrophotometer (AAS). From the characterization results, it is known that cobalt nickel ferrite is a hard magnet and has a cubic crystal structure. The magnetic hysteresis curve shows a coercivity of 715.68 Oe and a remanent magnetization of 18.38 emu/g. The absorption capacity obtained from Cu and Cr removal efficiency was 96.26%, with an adsorption capacity …

Radiation Physics and Chemistry

IntroductionSize-specific dose estimation (SSDE) is suggested for accurate measurement of CT dose. Various methods have been developed for SSDE calculation by both manual and automated methods. However, truncation artefact may affect the specific size determination and SSDE calculation. In this article, we evaluate how truncation affects measurements of SSDE and compare the manual SSDE measurement based on individual sizes (effective diameter, Deff and water equivalent diameter, DW) with the automated calculation using IndoseCT software on truncated CT images.MethodsA phantom study was conducted using Siemens SOMATOM Definition AS + CT scanner with two CTDI phantoms of different sizes, 22 cm and 32 cm. Phantom images were acquired by varying the phantom positioning to simulate truncation percentages (TP) of 5%, 10%, 15%, and 20%. The SSDE values were manually …

Radiation Physics and Chemistry

Apatite-wollastonite (AW) is an important biomaterial useful in clinical practice for tissue engineering and other applications. In this research paper, AW and B2O3-doped AW glass ceramics (GCs) were reported and investigated deeply by means of their ability to attenuate gamma-photons. The studied samples denoted by AW, AW-10B, and AW-20B as the B2O3 content from 0 to 20 mol% with the step of 10. Using FLUKA and other theoretical approaches, photon interaction parameters for narrow and broad beam transmission through the AW GCs were estimated for the 15 keV–15 MeV energy range. Also, the density of the GCs increased as the B2O3 content increased. The mass attenuation coefficients were found to be within the ranges 0.0231–13.5659 cm2/g, 0.0225–12.3561 cm2/g, and 0.0220–11.1079 cm2/g for AW, AW-10B, and AW-20B, respectively. The effective atomic number of the GCs fell within the …

Radiation Physics and Chemistry

The full energy peak efficiency (FEPE) of a gamma ray obtained from experimental studies using a high purity germanium detector (HPGe) can be easily reproduced by simulating the experiment in any desired geometry and energy range with Monte Carlo (MC) simulation methods. However, the dead layer (DL) thickness, which is one of the geometric information provided by the manufacturer, changes over time and affects the efficiency calculation, so it must be determined and compared with the initial value for the increases during the life-time of the detector. In this study, the general-purpose MC code PHITS and the special-purpose MC code GESPECOR were used to simulate a p-type HPGe detector and to determine the thickness of the frontal and lateral dead layer. As a result, it was observed that the frontal dead layer thickness increased from 0.7 mm to 1.075 mm, and the lateral dead layer thickness …

Radiation Physics and Chemistry

This study addresses the underexplored area of radiation interaction properties of antibiotics and their implications for stability, efficacy, and structural integrity. Focusing on a range of antibiotics classified by the United Arab Emirates National AMR Surveillance system, the research evaluates key metrics such as attenuation coefficients, effective electron density, exposure buildup factor, and photon transmission factors. Utilizing advanced MCNPX Monte Carlo simulation, we observed varied interaction patterns among different antibiotics, with significant findings on their photon interaction characteristics. The study highlights the potential molecular changes in antibiotics due to radiation exposure, emphasizing the importance of such research in fields from medical radiography to space exploration. Results indicate that radiation exposure can significantly affect antibiotic properties, underscoring the need for careful …

Radiation Physics and Chemistry

This study examines the thermoluminescence (TL) properties exhibited by hydroxyapatite (HAp) samples. The HAp samples were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. XRD results confirm that Hap corresponds to a hexagonal structure with a space group of P63/m. The study emphasizes the critical role of appropriate band-pass filters in TL measurements and explores the dose-dependent behavior of TL glow peaks. Examining the impact of varying heating rates (HR) on TL peak intensities revealed a positive correlation between HR and TL maximum peak temperatures, accompanied by a decrease in TL intensities. Notably, no thermal quenching effect was observed in HAp samples. The activation energy values were 0.51, 1.12, and 1.57 eV for Hoogenstraaten's method and 0.55, 1.19, and 1.65 eV for the Booth-Bohun-Porfianovitch method, demonstrating …

Radiation Physics and Chemistry

In the field of dentistry, the utilization of dental X-rays plays a pivotal role in ensuring accurate diagnoses for various dental conditions. A crucial aspect of this practice involves understanding how these X-ray emissions interact with dental braces. In the presented study, the details of how X-rays and gamma rays interact with different materials used in dental braces, namely stainless steel, nitinol, elgiloy, and beta-titanium alloys, were examined. This investigation was carried out through a combination of advanced simulation codes such as FLUKA and GEANT4, alongside theoretical calculations using the WinXCOM approach. A comprehensive analysis was conducted at fourteen distinct energy levels, ranging from 20 to 150 keV with 10 keV increments. The primary focus of this study revolves around quantifying the shielding characteristics of gamma and X rays as they traverse through these dental brace materials …

Radiation Physics and Chemistry

Recent studies related to the polymer gel dosimetry technique for radiation therapy have shown the importance of using additive of different concentrations to the polymer gel to improve the dose sensitivity. This work provides a significant improvement on the developed N-(3-methoxypropyl) acrylamide polymer gel dosimeter by incorporated with an inorganic salt of calcium chloride (CaCl2). Nuclear Magnetic Resonance relaxometry read out technique was used to examine dose-response after irradiation by measuring the change in the relaxation rate of R2. A medical linear accelerator with 6 MV photon beams and a 200 cGy/min dose rate was used to irradiate the developed gel with different absorbed doses. It was evidently clear from the findings that the R2 dose sensitivity of the developed polymer gel increased significantly by adding different concentrations of CaCl2 reaching 3.5 times higher than that without …

Radiation Physics and Chemistry

The neutron time-of-flight facility n_TOF at CERN is a spallation source dedicated to measurements of neutron-induced reaction cross-sections of interest in nuclear technologies, astrophysics, and other applications. Since 2014, Experimental ARea 2 (EAR2) is operational and delivers a neutron fluence of∼ 4⋅ 1 0 7 neutrons per nominal proton pulse, which is∼ 50 times higher than the one of Experimental ARea 1 (EAR1) of∼ 8⋅ 1 0 5 neutrons per pulse. The high neutron flux at EAR2 results in high counting rates in the detectors that challenged the previously existing capture detection systems. For this reason, a Segmented Total Energy Detector (sTED) has been developed to overcome the limitations in the detector’s response, by reducing the active volume per module and by using a photo-multiplier (PMT) optimized for high counting rates. This paper presents the main characteristics of the sTED, including …

Radiation Physics and Chemistry

Seven bioactive glasses in the system (50-x) B 2 O 3–4P 2 O 5–26CaO–20Na 2 O-xZnO:(x= 0–15 mol%) have been produced using melt quenching route. The prepared samples coded as BG1-BG7. The physical properties, average optical basicity, electronegativity, electronic polarizability, and radiation attenuation competence of the BG1-BG7 glasses have been examined. Non-crystalline state of samples confirmed via the XRD measurements. Density increased from 2.6274 g/cm 3 to 2.9406 g/cm 3 for BG1 to BG7 samples. The average optical basicity (˄ t h) changed from 0.748 to 0.838, electronic polarizability,(α 0− 2) enhanced from 1.812 to 2.008, while electronegativity,(χ a v) reduced from 2.352 to 2.245 as ZnO increased from 0 to 15 mol%. The BG1 sample possessed the lowest values of both mass (MAC)–linear (LAC)-attenuation coefficients, while BG7 possessed the highest values. The sample contains …