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Recent advances,challenges,and opportunities of inorganic nanoscintillators

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Frontiers of Optoelectronics 2020年第2期13卷 156-187页

作者： Santosh KGUPTA Yuanbing MAO radiochemistry division Bhabha Atomic Research CentreTrombayMumbai 400085India Department of Chemistry Illinois Institute of TechnologyChicagoIL 60616USA

This review article highlights the exploration of inorganic nanoscintillators for various scientific and technological applications in the fields of radiation detection,bioimaging,and medical theranostics.Various aspects of nanoscintillators pertaining to their fundamental principles,mechanism,structure,applications are briefly discussed.The mechanisms of inorganic nanoscintillators are explained based on the fundamental principles,instrumentation involved,and associated physical and chemical phenomena,etc.Subsequently,the promise of nanoscintillators over the existing single-crystal scintillators and other types of scintillators is presented,enabling their development for multifunctional applications.The processes governing the scintillation mechanisms in nanodomains,such as surface,structure,quantum,and dielectric confinement,are explained to reveal the underlying nanoscale scintillation phenomena.Additionally,suitable examples are provided to explain these processes based on the published data.Furthermore,we attempt to explain the different types of inorganic nanoscintillators in terms of the powder nanoparticles,thin films,nanoceramics,and glasses to ensure that the effect of nanoscience in different nanoscintillator domains can be appreciated.The limitations of nanoscintillators arc also highlighted in this review article.The advantages of nanostructured scintillators,including their property-driven applications,are also explained.This review article presents the considerable application potential of nanostructured scintillators with respect to important aspects as well as their physical and application significance in a concise manner.

关键词： scintillators nanoscintillators inorganic photoluminescence radioluminescence

Systematic study of the(n,2n)reaction cross section for^(121)Sb and^(123)Sb isotopes

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Chinese Physics C 2022年第5期46卷 77-94页

作者： R.K.Singh N.L.Singh R.D.Chauhan Mayur Mehta S.V.Suryanarayana Rajnikant Makwana B.K.Nayak H.Naik Tarak Nath Nag K.Katovsky Department of Physics Faculty of Sciencethe M.S.University of BarodaVadodara-390002INDIA Department of Physics Netaji Subhas University of TechnologyDwarkaNew Delhi-110078INDIA Institute for Plasma Research Gandhinagar-382428INDIA Nuclear Physics division Bhabha Atomic Research CentreMumbaiINDIA radiochemistry division Bhabha Atomic Research CentreMumbaiINDIA Department of Electrical Power Engineering Brno University of TechnologyBrno-61600Czech Republic

The cross sections of the^(121)Sb(n,2n)^(120)Sb^(m) and ^(123)Sb(n,2n)^(122)Sb reactions were measured at 12.50,15.79 and 18.87 MeV neutron energies relative to the standard ^(27)Al(n,α)^(24)Na monitor reaction using neutron activation and offline γ-ray spectrometry.Irradiation of the samples was performed at the BARC-TIFR Pelletron Linac Facility,Mumbai,India.The quasi-monoenergetic neutrons were generated via the ^(7)Li(p,n)reaction.Statistical model calculations were performed by nuclear reaction codes TALYS(ver.1.9)and EMPIRE(ver.3.2.2)using various input parameters and nuclear level density models.The cross sections of the ground and the isomeric state as well as the isomeric cross section ratio were studied theoretically from reaction threshold to 26 MeV energies.The effect of pre-equilibrium emission is also discussed in detail using different theoretical models.The present measured cross sections were discussed and compared with the reported experimental data and evaluation data of the JEFF-3.3,ENDF/B-VIII.0,JENDL/AD-2017 and TENDL-2019 libraries.A detailed analysis of the uncertainties in the measured cross section data was performed using the covariance analysis method.Furthermore,a systematic study of the(n,2n)reaction cross section for^(121)Sb and^(123)Sb isotopes was also performed within 14-15 MeV neutron energies using various systematic formulae.This work helps to overcome discrepancies in Sb data and illustrate a better understanding of pre-equilibrium emission in the(n,2n)reaction channel.

关键词： antimony (n,2n)reaction cross section 7Li(p,n)reaction neutron source neutron activation and offlineγ-ray spectrometry systematic formulae covariance analysis TALYS(ver.1.9)and EMPIRE(ver.3.2.2)codes

High pressure responsive luminescence of flexible Eu^(3+) doped PVDF fibrous mats

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Journal of Materials Science & Technology 2021年第7期66卷 103-111页

作者： Carlos Hernandez San tosh K.Gupta Jose P.Zuniga Jorge Vidal Rene Galvan Hector Guzman Lilian Chavez Karen Lozano Yuanbing Mao Department Department of Chemistry University of Texas Rio Grande Valley1201 West University DriveEdinburgTX 78539USA radiochemistry division Bhabha Atomic Research CentreTrombayMumbai400085USA Department of Electrical Engineering University of Texas Rio Grande ValleyEdinburgTX 78539USA Department of Chemistry Illinois Institute of Technology3105 South Dearborn StreetChicagoIL 60616USA

Exploring lanthanide doped materials and their high-pressure optical properties is important from the perspective of designing pressure sensors, piezoelectric materials, scintillators, and optoelectronic devices, just to mention a few. Understanding the high-pressure optical properties of polymeric fibrous mats provides significant advantages in terms of flexibility, tunability, facile processability, and malleability. In this work, we have developed flexible polyvinylidene difluoride(PVDF) fibrous mats doped with an Eu^(3+) source of Eu(NO_(3))_(3)·5H_(2)O(EN-PF) or Eu_(2)(SO_(4))_(3)(ES-PF) by a Forcespinning■ method. Microstructural analysis of these two systems indicates that Eu(NO_(3))_(3)·5H_(2)O and Eu_(2)(SO_(4))_(3) are homogeneously distributed and dispersed into the PVDF matrix. Fiber formation promotes a β-phase PVDF. Eu^(3+) doping increases the β-phase. Its fraction is larger for the ES-PF mats. To understand their high-pressure optical properties, their photoluminescence spectra have been taken at various pressures up to 58 GPa in a diamond anvil cell. High-pressure luminescence illustrates a clear change in asymmetry ratio, peak intensity, peak breadth, color coordinate, and color temperature of Eu^(3+) ions from both EN-PF and ES-PF with a different extent of changes. Specifically, Eu^(3+) ions in the ES-PF mats switch from asymmetric to symmetric environment as pressure increases. Those in the EN-PF mats present symmetric environment for all tested pressures. Both of the Eu^(3+) doped PVDF systems present irreversible changes. Therefore,the EN-PF fibrous mats present an opportunity to make pressure induced red-orange-yellow tunable phosphors for multifunctional applications.

关键词： Polyvinylidene difluoride Europium Fiber High pressure Luminescence

Separation Behavior of U(VI) and Th(IV) on a Mixed Ion Exchange Column Using 2,6-Pyridine Dicarboxylic Acid as a Complexing Agent and Determination of Trace Level Thorium in Uranium Matrix Employing High Performance Ion Chromatography

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International Journal of Analytical Mass Spectrometry and Chromatography 2013年第1期1卷 61-71页

作者： Vaibhavi V. Raut S. P. Roy M. K. Das S. Jeyakumar K. L. Ramakumar Product Development division Bhabha Atomic Research Centre Mumbai India Radioanalytical Chemistry division Bhabha Atomic Research Centre Mumbai India radiochemistry and Isotope Group Bhabha Atomic Research Centre Mumbai India

Retention behavior of U(VI) and Th(IV) as their 2, 6-pyridine dicarboxylic acid (PDCA) complexes on reversed phase and ion exchange (cation, anion and mixed ion exchange) columns was studied and based on the results, a simple ion chromatography method for the determination of trace level thorium in uranium oxide using 0.075mM 2, 6-pyridine dicarboxylic acid (PDCA) and 1M KNO3 in 1.2M HNO3 as eluent (flow rate 1 mL/min)was proposed. The advantage of the developed method is that the separation of uranium matrix is not required prior to the ion chromatographic determination of trace Th. Separation was carried out on a mixed ion exchange stationary phase and a 10?4 M arsenazo (III) solution was used as post column reagent for detecting the separated metal ions. The separation of Th from uranium using PDCA in the present investigation is attributed through cation exchange mechanism. A calibration plot was constructed by following the standard addition method over the concentration range of 0.25 to 10 ppm of Th in the presence of uranium matrix, which resulted in a linear regression coefficient of 0.9978. The precision of the method was better than 5% and the LOD for Th was found to be 0.1ppm (S/N=3). The method has been validated by comparing the results with the results obtained from ICP-MS analysis where the This separated from the uranium matrix. The proposed method is simple, rapid, accurate and cost effective compared to techniques like ICP-MS or ICP-AES and is suitable for the routine kind of analysis.

关键词： Ion Chromatography Uranium Thorium 2 6-Pyridine Dicarboxylic Acid

Ionic conductivity and dielectric studies of LiClO_(4)doped poly(vinylalcohol)(PVA)/chitosan(CS)composites

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Journal of Advanced Dielectrics 2014年第4期4卷 50-56页

作者： Sunil G.Rathod R.F.Bhajantri V.Ravindrachary P.K.Pujari T.Sheela Department of Physics Mangalore University Mangalagangotri 574199KarnatakaIndia Department of Physics Karnatak UniversityPavate Nagar Dharwad 580003KarnatakaIndia radiochemistry division Bhabha Atomic Research Centre TrombayMumbai 400085MaharastraIndia

This paper focuses on the dielectric constant("0),dielectric loss factor("00)and frequency dependent conductivity(ac)properties of newly prepared poly(vinylalcohol)(PVA)chitosan(CS)composite films incorporated with different concentrations of LiClO_(4).The composite films were prepared using solution casting technique.The complexation between salt and polymer host is confirmed by FT Raman and UV-Vis studies.The sample containing 20 wt.%LiClO_(4)exhibits a highest ionic conductivity of 3106 S/cm at room temperature.The dielectric properties of the composites follow non-Debye behavior.

关键词： Poly(vinylalcohol) chitosan dielectric properties conductivity

<i>γ</i>-Ray Modifications of Optical/Chemical Properties of Polycarbonate Polymer

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World Journal of Condensed Matter Physics 2015年第3期5卷 129-137页

作者： D. P. Gupta Shyam Kumar P. C. Kalsi V. K. Manchanda V. K. Mittal Chitkara Institute of Engineering and Technology Rajpura Patiala India Department of Physics Kurukshetra University Kurukshetra India radiochemistry division Bhabha Atomic Research Centre Mumbai India Department of Physics Punjabi University Patiala India

This work was aimed to investigate the changes brought about in the polymer polycarbonate irradiated to different doses of γ-radiation. Yellowing of the samples with the increase of γ-absorbed dose was observed. The changes in the optical properties were studied by recording UV-Visible absorbance spectra of the pristine and irradiated polycarbonate films. A simultaneous coexistence of direct and indirect band gaps was observed. The indirect band gap values were found lower in comparison to the corresponding values of direct band gap in the pristine and γ-irradiated poly-carbonate. Both types of the optical band gap energies had decreasing tendency with the increasing γ-radiation dose. Urbach energy was also determined from the tail of absorption edge which was found to have increasing tendency with progressive γ-radiation dose. Increase in carbon cluster size with the increasing γ absorbed dose was also shown. This increase in the number of carbon atoms (N) in a cluster can be correlated to the optical energy band gap (Eg). Moreover, the FTIR spectra of pristine and irradiated PC samples suggest chain scissoring with apparently the elimination of carbon di/monoxide.

关键词： γ-Radiation Polycarbonate Band Gap Carbon Cluster

Extended X-ray Absorption Fine Spectrometry for Np(Ⅴ) Adsorption to γ-FeOOH/Water Interface

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Extended X-ray Absorption Fine Spectrometry for Np(Ⅴ) Adsor...

Laser-induced plasma electron number density:Stark broadening method versus the Saha-Boltzmann equation

作者： YANG Chun-li ZHANG Sheng-dong RAO Lin-feng Department of radiochemistry Chemical Sciences division Lawrence Berkeley National Laboratory

Np(Ⅴ)is estimated to be the most hazardous radionuclide concerning its half-time(2.14×10year),radiotoxicity and environmental behavior.It has been reported that most of actinides can be sequestered by a variety of minerals,especially iron oxides as common components of rocks,soils and sediments.Np(Ⅴ)sorption at mineral-water interfaces are of great importance in contaminant regulation

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Plasma Science and Technology 2017年第2期19卷 43-51页

作者： Arnab SARKAR Manjeet SINGH Fuel Chemistry division Bhabha Atomic Research CentreMumbai 400 085India

We report spectroscopic studies on plasma electron number density of laser-induced plasma produced by ns-Nd：YAG laser light pulses on an aluminum sample in air at atmospheric pressure. The effect of different laser energy and the effect of different laser wavelengths were compared. The experimentally observed line profiles of neutral aluminum have been used to extract the excitation temperature using the Boltzmann plot method, whereas the electron number density has been determined from the Stark broadened as well as using the Saha-Boltzmann equation （SBE）. Each approach was also carried out by using the AI emission line and Mg emission lines. It was observed that the,SBE method generated a little higher electron number density value than the Stark broadening, method, but within the experimental uncertainty range. Comparisons of Ne determined by the two methods show the presence of a linear relation which is independent of laser energy or laser wavelength. These results show the applicability of the SBE method for Are determination, especially when the system does not have any pure emission lines whose electron impact factor is known, Also use of Mg lines gives superior results than Al lines.

关键词： plasma parameter laser induced plasma plasma electron density Saha-Boltzmannmethod Stark broadening method

Recent developments on PET radiotracers for TSPO and their applications in neuroimaging

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Acta Pharmaceutica Sinica B 2021年第2期11卷 373-393页

作者： Lingling Zhang Kuan Hu Tuo Shao Lu Hou Shaojuan Zhang Weijian Ye Lee Josephson Jeffrey H.Meyer Ming-Rong Zhang Neil Vasdev Jinghao Wang Hao Xu Lu Wang Steven H.Liang Center of Cyclotron and PET Radiopharmaceuticals Department of Nuclear Medicine and PET/CT-MRI CenterThe First Affiliated Hospital of Jinan UniversityGuangzhou 510630China Department of Neurology the First Affiliated Hospital of Jinan UniversityGuangzhou 510630China Department of Radiopharmaceuticals Development National Institute of Radiological SciencesNational Institutes for Quantum and Radiological Science and TechnologyChiba 263-8555Japan division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital&Department of RadiologyHarvard Medical SchoolBostonMA 02114USA Azrieli Centre for Neuro-radiochemistry Brain Health Imaging CentreCentre for Addiction and Mental Health&Department of PsychiatryUniversity of TorontoToronto ON M5T 1R8Canada Department of Pharmacy the First Affiliated Hospital of Jinan UniversityGuangzhou 510630China

The 18 kDa translocator protein(TSPO),previously known as the peripheral benzodiazepine receptor,is predominately localized to the outer mitochondrial membrane in steroidogenic cells.Brain TSPO expression is relatively low under physiological conditions,but is upregulated in response to glial cell activation.As the primary index of neuroinflammation,TSPO is implicated in the pathogenesis and progression of numerous neuropsychiatric disorders and neurodegenerative diseases,including Alzheimer’s disease(AD),amyotrophic lateral sclerosis(ALS),Parkinson’s disease(PD),multiple sclerosis(MS),major depressive disorder(MDD)and obsessive compulsive disorder(OCD).In this context,numerous TSPO-targeted positron emission tomography(PET)tracers have been developed.Among them,several radioligands have advanced to clinical research studies.In this review,we will overview the recent development of TSPO PET tracers,focusing on the radioligand design,radioisotope labeling,pharmacokinetics,and PET imaging evaluation.Additionally,we will consider current limitations,as well as translational potential for future application of TSPO radiopharmaceuticals.This review aims to not only present the challenges in current TSPO PET imaging,but to also provide a new perspective on TSPO targeted PET tracer discovery efforts.Addressing these challenges will facilitate the translation of TSPO in clinical studies of neuroinflammation associated with central nervous system diseases.

关键词： TSPO Microglial activation Neuroinflammation Positron emission tomography(PET) CNS disorders