Journal of Atomic, Molecular, Condensed Matter and Nano Physics

Relative Risk for a Class of Patients Based on Progressive Censored Data Exposed to Radiations Using Cox’s Proportional Hazard with a Set of Covariates

2022-06-29T07:45:30+00:00

An attempt has been made to estimate Relative Risks (RR) of a category of patients assumed to be progressive censored and exposed to multiple hazards including nuclear radiations and suffering from chronic non-communicable disease by fitting Cox’s proportional hazard regression model. Covariates are different age groups of patients, nature of stages of patients and treatment given to patients. The time dependent Weibull hazard rates have been estimated by using Maximum likelihood method. Any one of the three covariates considered here is taken as poorer immunity of a section of population because of exposure to high energy radiation of different kinds. The Relative Risk and Longevity estimates can further be used to construct life tables for such class of population, considering the censoring aspect of the data.

Effect of Nuclear Radiation Generated Thermal Spike on Degradation Reaction Kinetics of a Polymer SSNTD and Its Impact on Track Diameter

2022-06-29T08:04:54+00:00

It has been extensively studied that high polymer form an important group of materials used for solid state nuclear track detectors (SSNTD). The radiation induced damage not only leave tracks for microscopic examination but also change other physical properties of the material. One of them being the average molecular mass of the polymer. The change in this parameter which is induced by the radiation exposure can be studied and can give an estimate of the number of polymer chain scission, which has a direct influence on the track diameter and can give an estimate of the energy of radiation deposited inside the sample. From this the energy of the incoming particle flux can be calculated. In this paper a relationship between polymer degradation as given by the extent of the depolymerization reaction, the track diameter and energy of the incoming particle is sought.

Optically Stimulated Luminescence in Eu$^{3+}$ Doped NaLi$_2$PO$_4$ Phosphor: Studies on Effect of Particle Size

2022-06-29T08:29:03+00:00

We report the optically stimulated luminescence of Eu${}^{3+}$ doped NaLi${}_{2}$PO${}_{4}$ synthesized by solid state diffusion method which is crushed and sieved further using Ball milled for different time period (1 to 10 days) with different particle sizes ranging from micro to nano sizes are obtained. Formation of the material was confirmed by XRD analysis and matched peak to peak with JCPDS\#80-2110. Scanning electron microscope (SEM) images were used for determining its particle size(s). Optically stimulated luminescence (OSL) characteristics were studied to see the effect of particle size after irradiating with $\gamma$-rays from Co${}^{60}$ source for wide dose range (10 Gy-100 KGy). It was found that OSL sensitivity depends on particle size of the material. Easy method of synthesis, good sensitivity, low fading, good chemical stability, etc. make this OSLD nano phosphor a good candidate for radiation dosimetry using OSL.

Template Synthesis and Characterization of Ni Nanostructures

2022-06-29T09:33:00+00:00

Nanostructures of a typical ferromagnetic material, nickel are fabricated by electro-deposition (in a DC mode) within the pores of polycarbonate track etched membranes. The cylindrical pores with pore diameter 100 nm have been used for present study. Negative template method via two electrode potentiostatic arrangement in electrochemical cell has been used to synthesize the ordered array of one-dimensional Ni nanostructures. Deposition has been carried out at $41\pm2$ degree, 1.6 V and so formed one dimensional nanostructure has been obtained at a Copper substrate. The elegant approach of template synthesis has advantage that shape and diameter of one-dimensional nanostructure can be varied as per the requirement, by using the templates of different pore shapes and diameters. Crystalline nature of one-dimensional Ni nanostructures is confirmed by X-ray spectroscopy using Rigaku X-ray diffractometer. I-V characteristics have also been drawn using Keithley source meter, in order to check out the variation in electrical conductivity from bulk to nanoscale.

Passive Dosimeter Based on BaBrF:Tm$^{3+}$ Phosphor for $\gamma$-ray Dosimetry

2022-06-29T10:05:34+00:00

Thulium (Tm${}^{3+}$) ions doped Barium Bromide Fluoride (BaBrF) samples were synthesized successfully through the solid-state diffusion method. The crystal structure and phase purity of the synthesized sample were examined by Powder X-Ray Diffraction (PXRD) analysis. Dosimetric properties of $\gamma$-ray exposed samples of BaBrF:Tm${}^{3+}$ investigated. To obtain the maximum Thermoluminescence (TL) sensitivity of the material, the dopant concentration level and annealing temperature were optimized. It is observed that the dopant concentration 2.0 mol% of Tm${}^{3+}$ and the annealing at 673 K temperature the phosphor material exhibits maximum TL intensity. The $\gamma$-Ray dose-response, fading of the TL signal, and kinetic parameters of the TL glow curve were also investigated. TL sensitivity of the BaBrF:Tm${}^{3+}$ phosphor compared to the commercially available CaSO${}_{4}$:Dy (TLD-900) dosimeter used for radiation measurement. On the basis of their promising dosimetric characteristics, it can become a good TL dosimeter for passive dosimetry of high energy $\gamma$-ray radiation.

Linearly Modulated OSL in K$_{3}$Na(SO$_{4}$)$_{2}$:Eu$^{3+}$ Phosphor Irradiated With 48 MeV Li$^{3+}$ and 85 MeV C$^{6+}$ Swift Heavy Ions Beam

2022-06-29T11:07:58+00:00

K${}_{3}$Na(SO${}_{4}$)${}_{2}$:Eu${}^{3+}$ shows OSL when irradiated with swift heavy ion beams of Li${}^{3+}$ and C${}^{6+}$ at different fluences. The micro sample is prepared through solid state diffusion method along with its counter parts of ball milled (7 days) nanophosphor and co-precipitated nanophosphor samples. The material was characterized by XRD to confirm its formation in a single phase. Comparison of the experimental data with that of the data available in the literature (JCPDS data file \#74 0398) shows formation of a single hexagonal phase, with the space group P3 m1. Study on the particle size effect shows that particle size in the 75--106 $\mu$m rangeis more suitable for the linearly modulated-optically stimulated luminescence (LM-OSL) dosimetry in micro form. Dosimetric properties of the phosphor material using LM-OSL technique for blue light stimulation ($\lambda=470$ nm and $t=120$$ seconds) show that it is highly sensitive in the linear dose range. Here in this paper, we tried to find a relationship between detrapping probabilities and photoionization cross section using curve fitting (deconvolution) method. We also calculated and converted the fluence into doses using SRIM software. Data are presented indicating that the LM-OSL peak is composed of three overlapping components originating from populated traps with optical cross sections of 10${}^{-17}$-10${}^{-18}$ cm${}^{2}$. It was found that micro and ball milled nanophosphor Carbon ion beam irradiated samples dominates the photoionization cross section as compared with lithium ion irradiated samples, but co-precipitated sample is dominant in lithium irradiated samples. Which infers about the different trapping level formation and also recombination processes involved during the preparation and in readouts of samples.

NaLi$_{2}$PO$_{4}$: 0.5 mole% Eu$^{3+}$ Phosphor Used for Carbon Dosimetry

2022-06-29T11:44:20+00:00

New NaLi${}_{2}$PO${}_{4}$, phosphor doped with 0.5 mole% Eu${}^{3}$${}^{+}$ prepared by solid state method were used for carbon dosimetry. XRD of the material matched with the data available in the literature (JCPDS file #80-2110) and confirmed formation of the material in its orthorhombic structure. The TL of the carbon beam irradiated sample recorded on Harshaw TLD-3500 reader. The samples are irradiated for different fluencies from the range of $5\times 10^{9}$ to $1\times 10^{13}$ ions cm${}^{-2}$. TL glow curve consist of single main TL peak around 457 K surrounded by kinks at 408, 504 and 542 K. TL glow curve of the carbon irradiated sample has same shape as that of gamma irradiated one. With increasing dose the intensity is increases. The phosphor is much more sensitive than the standard available standard phosphor. It is about 6.5 and 41.3 times more sensitive than the TLD-100 and TLD-700H. For these range of fluences phosphor show sub-linearity. Efficiency of the for phosphor for C${}^{6+}$ with respect to gamma radiation is calculated and is around 0.50754 for the fluence of $5\times 10^{09}$ ions cm${}^{-2 }$.

OSL Dosimetry Using LiCaAlF$_{6}$:Eu Phosphor

2022-06-29T13:12:36+00:00

LiCaAlF${}_{6}$:Eu (0.1 mol%) OSLD phosphor material in microcrystalline powder form was prepared in a two-step process. First, through co-precipitation method and second by quickly melting it in a graphite crucible at around 900${}^{\circ}$C. It is a very novel and economic method of preparing this phosphor. The formation of the material in a single phase was characterized by XRD. Optically stimulated luminescence (OSL) and photoluminescence studies were done for its application in radiation dosimetry of high-energy. The materials were irradiated to different doses of $\gamma$-rays using ${}^{60}$Co radiation source and optically stimulated luminescence (OSL) decay curves were recorded. The powder material was found to be at least four times more sensitive than Al${}_{2}$O${}_{3}$:C (Landauer USA) commercially available OSL chips. Considering these facts, the material could be considered as a highly sensitive and suitable OSL phosphor.

Photoluminescence Properties of (Mg$^{2+}$) Divalent and (Al$^{3+}$) Trivalent Metal Coumarinolates Doped with Quinoline for PCLED Application

2022-06-29T13:47:17+00:00

Several Mg-Coumarinolates and Al-Coumarinolates doped with different concentrations of Quinoline were synthesized by simple chemical synthesis method and their PL spectra were studied. Usually, pure coumarin along with the chelates show weak luminescence and the emission is witnessed around 450 nm with excitation around 350 nm. Hence, such chelates do not find any practical applications. Addition of quinoline in lesser amount affects the emission and excitation of Mg-Coumarin and Al-Coumarin considerably. Intense photoluminescence is observed in these Mg based mixed chelates. In all samples, a well-defined emission band at 490 nm is observed with broad excitation in 350 nm to 470 nm range. Hence good overlap of excitation with 420 nm and 440 nm LED emission makes these materials suitable for white LED applications.

Synthesis of KZnF$_{3}$ Phosphors by Co-Precipitation Method

2022-06-29T14:10:25+00:00

Synthesis of KZnF${}_{3}$ is rather tedious. Typical problems of fluoride synthesis are faced with more acuteness. Even in wet chemical preparations, use of hygroscopic starting materials like zinc chloride or nitrate presents considerable difficulties. A simple precipitation synthesis of KZnF${}_{3}$ with aqueous solutions of zinc sulfate and potassium fluoride is described. Precipitation at the room temperature produces the compound profoundly contaminated with hydroxide phase. Phase pure compound is obtained when boiling solutions are mixed. Activators Cerium and europium could be incorporated by adding the corresponding sulfates to zinc sulfate solution during the precipitation. As prepared phosphor exhibited typical Ce${}^{3+}$ luminescence. For obtaining Eu${}^{2+}$ luminescence, the phosphor had to be given reducing treatment.

Luminescence Characteristics of LiCaAlF$_6$:Eu TLD Phosphor

2022-06-29T14:38:36+00:00

The material LiCaAlF${}_{6}$:Eu (0.1 mol%) in microcrystalline form was prepared through water solution coprecipitation method followed by melting it at around 900 ${}^\circ$C in a graphite crucible. The ingot was crushed and sieved through standard sieves to obtain powder approximate in the range 100-125 $\mu$m. The material was annealed at around 200-800 ${}^\circ$C. The material was characterized by XRD. The materials were irradiated to different doses of $\gamma$-rays using ${}^{60}$Co radioactive source and thermoluminescence (TL) glow curves were recorded. The powder material was found to be at least 10 times more sensitive than CaSO${}_{4}$:Dy commercially available TLD pellets. However, as the dosimetry peak is at around 180 ${}^\circ$C, there is fading around 20%. Considering these facts, the material could be considered as a highly sensitive and suitable TLD phosphor.

Preface

2022-06-29T14:57:25+00:00

The 21st National Conference on Solid State Nuclear Track Detectors and Their Applications (SSNTDs-21), a three-day national conference was jointly organized by the Department of Physics, Ramjas College and Department of Physics and Astrophysics, University of Delhi in collaboration with the Nuclear Track Society of India (NTSI) during January 29-31, 2021. This was the 21st conference into biennial series of the conferences and was inaugurated by Prof. P.C. Joshi, Vice Chancellor, University of Delhi and Prof. Mahesh Verma, Vice Chancellor, GGSIP University, Delhi. The organizing team comprised of Dr. Manoj Kumar Khanna, Principal, Ramjas College (as Patron), Prof. P.D. Sahare, Dr. Rajesh Kumar and Dr. Ashok Kumar as the convener, co-convener and organizing secretory of the conference, respectively. The office bearers of NTSI and advisory committee also played a vital role in organizing the conference.

Solid State Nuclear Track Detector (SSNTDs) are a class of passive detectors, developed by R.L. Fleischer, P.B. Price and R.L. Walker in the early 1960 and they have found in numerous applications in various field of science and technology. SSNTDs have been recognize as very potential and effective tools in exploring various research area. Apart from the direct applications of far reaching consequences in nuclear physics, other areas, such as, biomedical sciences, cosmic rays and space physics, environmental sciences geochronology and geophysics, materials sciences, lunar sciences, meteorites and tektites and microanalysis and mine safety, nuclear technology, uranium prospective and most recently nano-/microtechnology, etc. have been greatly influence by SSNTDs.

They have a very important role to play in radiation measurements, micro technology and dosimetry and thus they are potent enough in spreading awareness about the radiation environment and its impact on the general public and the academic peers. In order to disseminate the knowledge generated in this fast-growing field, there was a need to bring material science and radiation community on a common platform and discuss various aspects related to it.

In view of this, the NTSI along with Ramjas College and Department of Physics and Astrophysics, University of Delhi organized a very comprehensive three-day conference, SSNTDs-21 at the University of Delhi. The focused areas of the conference included, basic studies and methodology; latent tracks in materials and ion track technology; heavy ion nuclear physics and cosmic rays; radon/thoron studies; radiation measurements and dosimetry; trace analysis; Nuclear track filters and their applications; fission track dating and geochronology; instrumentation, devices and software in these areas; SSNTDs in teaching; radiation induced modification of materials; luminescence and it’s applications; synthesis and characterization of materials, etc.

The conference was attended by more than 150 scientists, academicians and researchers having 104 oral presentations, 23 invited talks during 12 technical sessions chaired by eminent scientists and scholars. Scientist from different institution and universities all over the country participated in the conference. Young scientist awards were also given under various categories for best papers presentations. The conference was sponsored by UGC, CSIR, INSA and DRDO of Government of India.

This special issue contains some ‘Selected and Peer-Reviewed’ full length 11 papers out of the total more than hundred papers presented in the ‘21st National Conference on Solid State Nuclear Track Detectors and Their Applications’ (SSNTD-21). The articles presented in the conference covered a wide range of topics. However, only articles of high quality were selected and the topics include synthesis, characterization and applications of some inorganic luminescent phosphors for their applications in radiation dosimetry of high-energy radiations including swift heavy ions (SHI) using TL/OSL techniques. There are also papers on polymer solid state track detectors. Some papers on nanophosphors have also been included for their related applications. We hope that this special issue of the ‘Journal of Atomic, Molecular, Condensed Matter and Nano Physics’ will be useful to the workers in this field.

Lead Guest Editor:

Prof. P.D. Sahare
Department of Physics and Astrophysics
University of Delhi
Delhi 110007, India

Associate Guest Editors:

Dr. Rajesh Kumar
University School of Basic and Applied Sciences
GGS Indraprastha University
New Delhi 110078, India

Prof. Ashok Kumar
Department of Physics
Ramjas College (University of Delhi)
Delhi 110007, India

Journal of Atomic, Molecular, Condensed Matter and Nano Physics

Relative Risk for a Class of Patients Based on Progressive Censored Data Exposed to Radiations Using Cox’s Proportional Hazard with a Set of Covariates

Effect of Nuclear Radiation Generated Thermal Spike on Degradation Reaction Kinetics of a Polymer SSNTD and Its Impact on Track Diameter

Optically Stimulated Luminescence in Eu\(^{3+}\) Doped NaLi\(_2\)PO\(_4\) Phosphor: Studies on Effect of Particle Size

Template Synthesis and Characterization of Ni Nanostructures

Passive Dosimeter Based on BaBrF:Tm\(^{3+}\) Phosphor for \(\gamma\)-ray Dosimetry

Linearly Modulated OSL in K\(_{3}\)Na(SO\(_{4}\))\(_{2}\):Eu\(^{3+}\) Phosphor Irradiated With 48 MeV Li\(^{3+}\) and 85 MeV C\(^{6+}\) Swift Heavy Ions Beam

NaLi\(_{2}\)PO\(_{4}\): 0.5 mole% Eu\(^{3+}\) Phosphor Used for Carbon Dosimetry

OSL Dosimetry Using LiCaAlF\(_{6}\):Eu Phosphor

Photoluminescence Properties of (Mg\(^{2+}\)) Divalent and (Al\(^{3+}\)) Trivalent Metal Coumarinolates Doped with Quinoline for PCLED Application

Synthesis of KZnF\(_{3}\) Phosphors by Co-Precipitation Method

Luminescence Characteristics of LiCaAlF\(_6\):Eu TLD Phosphor

Preface