042528   RAO G V G, BABU SHAIK, KALIMULLA T, RAO K G (Physics Dep, KoneruLakshmaiah Education Foundation, Guntur, Andhra Pradesh, Email: babu.computers@gmail.com) : Intermolecular interaction studies of binary liquid mixtures of 2-methyl cyclohexanone with o-anisidine/m-anisidine/p-anisidine in terms of thermoacoustic parameters at different temperatures. Indian J Pure Appl Phys 2020, 58(9), 657-66.

In this present investigation, the thermo-acoustic fundamental parameters such as density (ρ) and speed of sound (U) were measured experimentally for the anisidine isomers (2-methoxy aniline, 3-methoxy aniline and 4-methoxy aniline) with solvent agent such as 2-methyl cyclohexanone in various concentrations within temperatures from 303.15 to 313.15K (5K interval) at ambient atmospheric pressure. From these experimentally determined values, various thermo-acoustic parameters of excess isentropic compressibility, K^E_S and excess molar volume, V^E_M are calculated. The calculated excess functions were correlated with reduced Redlich-Kister polynomial equation and results are analyzed in terms of structural molecular interactions between component molecules. Moreover, calibration of the partial molar volume's and partial isentropic compressibility’s of components shows strong interaction in 2-methyl cyclohexanone + 4-methoxy aniline than any other composites. In addition to the FTIR characteristic spectrum of all combinations at different concentrations gives the more promising features such as interaction behavior that helps our analysis to guide the interactions of individual bonding strength of the molecules.

9 illus, 5 tables, 20 ref

042527   SAXENA N , SHARMA V , SHARMA R, SHARMA K K , JAIN K K , CHAUDHARY S (Electronics & Communication Engineering Dep, Malaviya National Institute of Technology Jaipur, Jaipur, Email: rsharma.ece@mnit.ac.in) : Enhancement in structural, morphological and optical features of thermally annealed zinc oxide nanofilm. Indian J Pure Appl Phys 2020, 58(8), 642-8.

This paper presents the study of surface morphological, optical and microstructural features of zinc oxide (ZnO) nanofilm layered upon p-type Si substrate of <100> orientation by employing conventional RF magnetron sputtering system at different annealing temperatures. The effect of annealing on the nano-film is examined using different characterization techniques such as Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), FTIR (Fourier Transform Infrared Spectroscopy), UV-vis spectroscopy and Raman spectroscopy. The sharp diffraction peak at (002) orientation is seen by the XRD spectra which signifies a better growth of single crystalline thin film along the z-axis with the hexagonal wurtzite crystal structure. The surface morphological study shows that the grain size of the thin film intensifies from 22.06 nm to 36.77 nm when the annealing temperature is increased whereas there is a decrease in the values of lattice constants (a=b, c), FWHM (full width at half maximum), residual stress, lattice strain and dislocation density by increasing annealing temperature. The enhancement in the grain size makes the thin film appropriate for MEMS device applications including piezoelectric energy harvesters, gas sensors, etc. The optical bandgap of the ZnO thin film is estimated using Kubelka-Munk (KM) approach and it decreases from 3.23 to 3.16 eV for As-deposited, 400 °C, 600 °C and 800 °C respectively which makes the annealed thin film apposite for optoelectronic device applications. The intensity of the Raman peaks strengthens with the annealing temperature. These results prove that the annealing extensively enhances the crystallinity, structural, morphological and optical features of ZnO thin film and hence becomes suitable for nanoelectronic device applications.

6 illus, 1 table, 14 ref

042526   AYDIN A , KETENOGLU B , BOSTANCI E (Computer Engineering Dep, Ankara Univ, Ankara - 068 30 , Turkey, Email: ebostanci@ankara.edu.tr) : Optimization of sase operation for an X-ray free-electron laser using multiple objective evolutionary algorithms. Indian J Pure Appl Phys 2020, 58(8), 635-41.

Performance of Self Amplifed Spontaneous Emission (SASE) operation for an X-ray Free-Electron Laser (FEL), is optimized by Multiple Objective Evolutionary Algorithms (MOEA). Different types of hybrid planar undulators are considered to achieve 0.5 Å ≤ λFEL ≤ 1.5 Å wavelength range. This demand is regarded as a continuous optimization problem, and hence, an evolutionary algorithm is designed to find optimal FEL performance parameters. An encoding scheme comprising of undulator period (λ_u) and undulator gap (g) is adopted here to find optimal values for saturation power (P_sat) and λ_FEL subject to several physical constraints on λu and g such as the ratio of g/λu and L_sat. It is shown that MOEA gives optimal solutions for estimation of L_sat with plausible Psat values.

4 illus, 1 table, 33 ref

042525   MISHRA S P, GARNAYAK S , BHUYAN R K, NATH G (Physics Dep, Veer Surendra Sai Univ of Technology, Sambalpur-768 018, Email: ganeswar.nath@gmail.com) : Design and analysis of effective graded microwave absorbing material for low observable technology. Indian J Pure Appl Phys 2020, 58(8), 629-34.

Compositional designing of effective graded radar absorbing material for low observable technology is always a challengeable task in material science. The micro scale or quantum scale interaction of electromagnetic radiation is depends on the characteristic property of each atom or their assembly in a material composition. The filler and matrix in a composite structure plays a vital role between the advantages in electromagnetic absorption capability and the disadvantage due to difficulties in practical homogenous dispersion with weight concentration. The present work describes synthesis of biomaterial based effective graded radar absorbing material (RAM) for application in stealth technology. Ultrasonic treated rice husk raw material shows a significant increase of dielectric property of the composite material blended with epoxy resin. The significant modification in surface of the biomaterials with ultrasonic wave provides the enhanced mechanical strength as well as hardness of the material. Bio ceramic material composed of china clay and carbon rich waste rice husk ash possesses good dielectric loss for frequency 10 GHz and reflection loss -24.5 dB which is quite significant for stealth technology. Scanning electron microscopy (SEM) study shows good dispersion of rice husk ash in the epoxy matrix. Frequency dependence of both dielectric constant and dielectric loss are measured in the X band frequency range (8.2- 12.4GHz). This low cost laboratory scale synthesized RAM find its application in designing of stealth aircraft and jet fighter for military purposes.

8 illus, 13 ref

042524   KUMAR C, GOYAL R (School of Information Univ, New Delhi-110 078, Email: chakreshk@gmail.com) : Impact of high speed differential quadrature amplitude modulation using hybrid optical amplifier for super dense wavelength division multiplexing system. Indian J Pure Appl Phys 2020, 58(8), 624-8.

In this paper, a Differential Quadrature Amplitude Modulation (DQAM) technique for 200 x100 Gbps Super Dense Wavelength Division Multiplexing (SD-WDM) system is proposed. Optimized rating outcome in terms of the quality factor, bit error rate, crosstalk, and acceptable minor effect of the channel spacing with the support of RAMAN-EDFA-RAMAN Hybrid Optical Amplifier (HOA) is reported.

7 illus, 1 tables, 20 ref

042523   MARIAMMAL K , SHERINMARY R , BRITTOPARI J , VAITHIYANATHAN D (Electronics Engineering Dep, Anna Univ, Chennai, Tamil Nadu, Email: dvaithiyanathan@nitdelhi.ac.in) : Multiple bandwidth fir filter design with adaptive algorithms for hearing aid systems. Indian J Pure Appl Phys 2020, 58(8), 605-23.

Digital Filter design plays a vital role in signal processing and communication applications. This paper proposes a hearing loss system model with Variable Bandwidth FIR Filter (VBF) and adaptive algorithms for the application to listening. The tunable band filter is designed to provide an appropriate sound level. This filter has several sub-filters each of which is designed with set of selected bandwidths. The sub-bands obtained are adjusted with proper magnitude by trial and error method. Algorithms such as Least Mean Square (LMS), Normalized Least Mean Square (NLMS) and Recursive Least Squares (RLS) are incorporated to improve the quality of the signal. The filter thus designed is examined by taking a number of audio signals. The tests on various hearing loss cases with different type of input signal suggest that this method is capable of reproducing a signal which sounds exactly the same as the original signal. The multiple bandwidth filters is analyzed with mild, moderate, profound and severe hearing loss patterns and the results are reported. The matching error is calculated between ideal response and actual response. The result show that the designed filter provides acceptable minimum matching error and it lies in the range 0 to 2.5dB.This filter design is implemented in TMS320C6711 processor and is tested for sinusoidal input signal.

47 illus, 8 tables, 28 ref

042521   SAMBATHKUMAR k (Physics Dep, A Govt Arts Coll, Villupuram - 605 602, Email: sa975kumar@gmail.com) : Molecular structure and vibrational spectra of 2, 4, 6 -trimethylbenzene sulphonyl chloride (FTIR & Raman) by quantum chemical calculations. Indian J Pure Appl Phys 2020, 58(8), 589-98.

The 2, 4, 6-trimethylbenzene sulphonyl chloride was characterized using IR and Raman spectral data. The molecular electrostatic potential surface of the 2,4,6-trimethylbenzene sulphonyl chloride (TMBS) has been visualized in electropositive potential in the region of the CH3⁺ group and most electronegative potential in the two oxygen atom has strong binding group. The HOMO and LUMO energies and electronic charge transfer confirms that local reactivity and global reactivity descriptors. The rate constant of 2, 4, 6-trimethylbenzene sulphonyl chloride shows strong temperature dependence. Molecular electrostatic potential (MEP) were also calculated for identification. Temperature dependence of various thermodynamic properties like (Cº_p,m, Sº_m and (Hº_m) is increase with increase in temperature for the structure.

11 illus, 6 tables, 24 ref

042520   SANGWANA A, SINGH N (Physics Dep, Singhania Univ, Jhunjhunu - 333 515, Email: sangwananita.098@gmail.com) : Amplitude modulation and demodulation of a coherent electromagnetic wave in magnetized doped III-V semiconductors. Indian J Pure Appl Phys 2020, 58(7), 569-80.

This present paper is concerned with the analytical study of the amplitude modulation and demodulation of a coherent electromagnetic wave in magnetized doped III-V semiconductors. Utilizing the hydrodynamic model of a semiconductor plasma, the modulation indices for upper (+) and lower (–) side bands have been obtained. The incorporation of carrier diffusion in the nonlinear laser-semiconductor interaction adds new dimension to the analysis. The numerical estimations have been made for n-InSb crystal at liquid nitrogen temperature illuminated by frequency doubled pulsed 10.6 µm CO₂ laser. The problem has been analyzed in two different wave regimes (in the presence as well as absence of phenomenological acoustic damping parameter (Γ_a) over a wide range of externally applied magnetic field (incorporated in terms of cyclotron frequency ω_c). The results indicate that in absence of damping parameter, the absorption of coherent electromagnetic radiation takes place completely in all possible wavelength regimes when ω_c~ (v² + ω)^1/2; v and ω₀ being the electron collision frequency and pump frequency, respectively. Moreover, the carrier diffusion modifies amplitude modulation and demodulation processes significantly. The damping parameter additionally assumes a significant role in choosing the range of parameters and selecting the modulated side band mode.

32 illus, 32 ref

042519   TINKER S, MISHRA S R, SHARMA R P (Mechanical Engineering Dep, National Institute of Technology, Yupia, Papum Pare - 791 112, Arunachal Pradesh, Email: rpsharma@nitap.ac.in) : Influence of soret and dufour effect on MHD flow over an exponential stretching sheet: A numerical study. Indian J Pure Appl Phys 2020, 58(7), 558-68.

The present paper analyzes the effect of chemical reaction on free convection MHD motion of steady, laminar, incompressible liquid under the influence of heat source/sink. The motion is considered over an exponential radiative extending surface with a magnetic field. An appropriate similar transformation is employed to convert the nonlinear system of partial differential equations (PDEs) to a set of ordinary differential equations (ODEs). Due to the high nonlinearity, the analytical approach for these coupled nonlinear equations does not hold good. Therefore, these transformed ODEs are solved by using numerical techniques adopting Runge-Kutta fourth-order method accompanied by shooting technique. The behavior of different physical parameters on the motion phenomena is shown via diagrams. However, as a concluding remark, the major outcomes of the present investigation are described as: the buoyant forces overshoot the velocity profile significantly whereas the fluid temperature retards with an increasing Soret number. Finally, the chemical reaction parameter favors retard the concentration profiles resulted in reducing the thickness of the solutal boundary layer.

19 illus, 31 ref

042518   SANDHYA A, REDDY G V R, DEEKSHITULU G V S R (Mathematics Dep, VR Siddhartha Engineering Coll, Kanur - 520 007, Vijayawada, Email: akuri.sandhya@gmail.com) : Radiation and chemical reaction effects on MHD Casson fluid flow past a semiinfinite vertical moving porous plate. Indian J Pure Appl Phys 2020, 58(7), 548-57.

A speculative investigation has been presented to explore the significant features of MHD convective Casson fluid flow past a semi-infinite moving vertical porous plate with heat source/sink are included in the flow configuration. The governing partial differential equations are remodeled into ordinary differential equations using appropriate non-dimensional variables. The ensuing differential equations are solved analytically using two term perturbation technique method. The result of flow heat and mass transfer analysis on the velocity, temperature and concentration profiles and also physical parameters like Skin friction, Nusselt number, and Sherwood numbers are shown graphically, also shown in tabular form. The results shows that Casson parameter enhances the velocity, temperature and concentration fields are decreases for increasing the values radiation and chemical reaction. Under some restriction the resultant outcome were compared with previous published results and is found in admirable agreement.

20 illus, 2 tables, 15 ref

042516   PORWAL A K (Space Application centre (SAC), Ahmedabad - 380 015, Email: anshulporwal1234@gmail.com) : Development of vacuum compatible, multi-mode operation light source. Indian J Pure Appl Phys 2020, 58(7), 531-7.

Light sources are used extensively at various stages of development and characterization of an electro-optical (EO) payload like Cartosat, HySIS, Microsat etc. These sources are required to characterize many critical parameters of EO payload like photo response non uniformity (PRNU), noise performance, saturation radiance etc. Currently integrating sphere with quartz tungsten halogen (QTH) lamp is widely used for payload characterization. These lamp sources generally operate in continuous mode in clean room environment and thermo-vacuum. In case of high resolution payloads, time-delay and integration (TDI) detectors are used to improve signal collection. For characterization and testing of such payloads multi-mode (pulsed and continuous) light source (switching at kHz rate in synchronization with payload electronics) with specific spectral range is required. Pulse mode operation requirement cannot be met using QTH lamps. To cater to such need a LED based indigenous source has been developed. This paper delineates circuit design and implementation of driver and characteristics of the source is also discussed. Proposed source is capable to synchronize and operate in multi-mode with external clock pulse with high achieved linearity (>99 %) and high stability (>99 %) in vacuum condition.

18 illus, 4 tables, 11 ref

042515   PRASAD D, SINGH R , RANJAN A, KUMAR H T (Electronics & Communication Engineering Dep, Jamia Millia Islamia, New Delhi - 110 025, Email: dprasad@jmi.ac.in) : Grounded capacitors single resistance controlled oscillator using single FTFNTA. Indian J Pure Appl Phys 2020, 58(7), 525-30.

In this manuscript, grounded capacitor single resistance controlled oscillator using four terminal floating Nullor transconductance amplifier (FTFNTA) is presented. It requires only one FTFNTA, two grounded resistors and two grounded capacitors. Oscillation condition (OC) and oscillation frequency (OF) are solely controlled through resistors. The non-ideal behaviour of the proposed structure has also been analyzed. Sensitivity analysis shows that the proposed structure is insensitive to component variations. The simulation results have been demonstrated and discussed using a SPICE simulation using 180 nm TSMC technologies. Monte Carlo analysis is also analysed for the proposed structure.

9 illus, 1 table, 35 ref

042514   JHA S, TRIPATHI D (Physics Dep, Gujarat Univ, Ahmedabad - 380 009, Email: sushmajha31@gmail.com) : In-situ polymerization of pyrrole in PVA-PVP matrix: Optimization of oxidant/monomer ratio and its effect on dielectric properties of polymer blend films. Indian J Pure Appl Phys 2020, 58(7), 516-24.

Free standing and flexible polymer blend films of PPy (poly pyrrole) doped in PVA (poly vinyl alcohol) – PVP (poly vinyl pyrrolidone) matrix with varying concentrations of PPy have been prepared by solution cast technique at room temperature. In-situ polymerization of pyrrole monomer (Py) in PVA-PVP matrix has been carried out using FeCl3 as oxidant. The effect of monomer amount and monomer to oxidant ratio on the dielectric parameters (such as dielectric constant, dielectric loss, loss tangent, ac conductivity, complex electric modulus, complex impedance) of PPy doped PVA-PVP polymer blend films have been studied in the frequency range of 20 Hz to 2 MHz. Two different molar concentrations (0.15 M and 0.30 M) of oxidants have been taken and for each oxidant concentration, four varying concentrations of monomer have been used to optimize the results. The blend films having oxidant to monomer molar concentration ratio of 0.5 in both the cases (i.e. 0.15 M and 0.30 M) have been found to be smooth, flexible, mechanically strong and easy to process. These films have shown very systematic change and improved values of dielectric parameters within the experimental frequency range. Enhanced dielectric parameters (complex permittivity, ac conductivity and electric modulus) values for films having oxidant to monomer molar ratio of 0.5 suggest the organized growth of PPy chain in the matrix of PVA-PVP.

21 illus, 14 ref

042513   SHARMA K, MELAVANKI R, MUTTANNAVAR V T, THIPPERUDRAPPA J T, PATIL N R, KUSANUR R (Physics Dep, M S Ramaiah Institute of Technology, Bangaluru - 560 054, Email: melavanki73@gmail.com) : Examining the spectroscopic features and quantum chemical computations of a quinoline derivative: Experimental and theoretical insights into the photophysical characteristics. Indian J Pure Appl Phys 2020, 58(7), 503-15.

The solvatochromic studies in a Quinoline derivative molecule namely Quinolin-8-ol (QO) have been carried out at ambient temperature using absorption and fluorescence spectroscopy. The QO molecule shows the bathochromic shift with increase in solvent polarity demonstrating π → π* transition. The solvatochromic data coupled with quantum mechanical calculations has been used to estimate change in dipole moment of the molecule after excitation. It has been found that excited state dipole moment is greater than the corresponding ground state dipole moment. Further, it is observed that excited and ground state dipole moments are parallel. The chemical reactivity and kinetic stability of QO molecule are investigated using Frontier molecular orbital (FMO) analysis. Natural bond orbital (NBO) analysis shows proton transfer within the selected donor-acceptor depicting large energy of stabilization for QO molecule. The calculated Fukui functions infer the local softness and local eletrophilicity index of QO molecule. The theoretically simulated UV-Vis absorption spectrum of QO molecule matches well with the experimental spectrum.

14 illus, 9 tables, 64 ref

042512   SINGH R P, SINGH S, GILL R, KUMAR R, SHARMA P , KUMARF G, ADRIAAN S, LUYT A S (Physics Dep, Central Univ of Rajasthan, Ajmer - 305 817, Email: sukhmandersingh@curaj.ac.in) : Computational studies for the effective electrical conductivity of Copper powder filled LDPE/LLDPE composites. Indian J Pure Appl Phys 2020, 58(6), 486-93.

The effective electrical conductivity (EEC) of low density polyethylene (LDPE) and linear low density polyethylene (LLDPE) polymer composites filled with copper has been studied. The nonlinear behavior has been observed for effective electrical conductivity versus filler content. Several approaches have been described to predict the electrical conductivities of polymer composites. EEC is described by artificial neural network (ANN) and it demonstrates the accurate match of experimental data for EEC with different training functions (TRAINOSS, TRAINLM, TRAINBR, TRAINSCG, TRAINBFG, and TRAINRP). The ANN approach satisfied the experimental data for EEC of polymer composites reasonably well. The complex structure encountered in LDPE/Cu and LLDPE/Cu, along with the difference in the EEC of the components, make it difficult to estimate the EEC exactly. This is the reason for which artificial neural network has been employed here. By using ANN approach experimental results indicate that EEC of polymer composites increases with increasing filler content at the same concentration.

15 illus, 1 table, 46 ref

042511   SINGH S, RAJ B (Electronics & Communication Engineering Dep, Dr B R Ambedkar National Institute of Technology, Jalandhar - 144 011, Email: shailendras.ec.18@nitj.ac.in) : Study of parametric variations on hetero-junction vertical t-shape TFET for suppressing ambipolar conduction. Indian J Pure Appl Phys 2020, 58(6), 478-85.

This paper investigates a hetero-junction vertical t-shape tunnel field effect transistor and discussed various methods for the suppression of ambipolar conduction for the first-time utilizing computer aided design sentaurus simulation tool. This device is primarily consisting of dual gate silicon based gated p-i-n diode for eminent control over the channel. Further, introduction to the 10 nm silicon germanium layer to the channel makes aggressive improvement to the device characteristics. Unlike to the conventional TFET, we have considered the effective techniques like gate-on-drain overlapping, gate-on-channel underlapping and different drain doping concentration up to 1 × 10¹⁸ cm⁻³, which are used to conquer the ambipolar conduction by increasing the tunneling barrier width at the drain channel edges. The device surface potential performance is also analyzed for different parameters like drain doping concentration, gate-source voltage, silicon germanium Si_1-xGe_x mole fraction x and gate oxide thickness. Moreover, the vertical and lateral electric field inspect for determining the tunneling rate. The path distribution of source channel and drain in vertical direction will increase the scalability of the simulated device.

15 illus, 28 ref

042510   VENKATACHALAM P, RAJALAKSHMI S (Physics Dep, Periyar Arts Coll, Cuddalore - 608 002, Email: rajalakshmiaup@gmail.com) : Performance of ZnO-Nb2O5 core/shell and aluminium doped ZnO electron transporting layer with CdS/CdSe quantum dot-sensitized solar cells. Indian J Pure Appl Phys 2020, 58(6), 470-7.

In the present investigation, solar cells have been fabricated using Cds/CdSe quantum dots sensitized ZnO photoanode for solar cell application. Photocurrent-voltage analysis and electrochemical impedance spectroscopy (EIS) measurements have been performed to investigate the electron transport and recombination of charge carriers in quantum dot-sensitized solar cells (QDSSCs) based on ZnO photoanodes. This dynamic study reveals that the CdS/CdSe sensitized aluminium (Al) doped ZnO NPs photoanode solar cell performs ultrafast electron transport and high charge collection efficiency (80 %). As a consequence, a power conversion efficiency as high as 5.32 % (J_SC = 12.86 mA/cm², V_OC = 600 mV, FF = 69 %) for aluminium doped ZnO NPs/CdS/CdSe photoelectrode based QDSSC is observed under one sun AM 1.5 G illumination (100 mW cm^-2). This result highlights the necessity of treating QD-sensitized solar cells from another perspective than dye sensitized solar cells, considering the fundamental differences in their behavior.

5 illus, 1 table, 29 ref

042509   PANDYA P B, PRATAP A (Applied Physics Dep, The M S Univ of Baroda, Vadodara - 390 001, Email: apratapmsu@yahoo.com) : Glass forming ability of ZBLAN glass. Indian J Pure Appl Phys 2020, 58(6), 465-9.

A ZBLAN glass of the following composition: 53 mol. % ZrF4, 20 mol. % BaF2, 4 mol. % LaF3,3 mol. % AIF3, 20 mol. % NaF is studied for predicting its glass forming ability (GFA). The GFA of a ZBLAN glass is evaluated by estimating the Gibbs free energy difference (ΔG) between the undercooled liquid and the corresponding equilibrium solid phases. Other GFA criteria (T_rg=T_g/T_l, T_x/T_l, γ=T_x/T_g+T_l, ΔT_xg=T_x-T_g, T_g/T_m) are also calculated. Here, the approximation for ΔG considering constant specific heat difference (ΔC_P) over a wide temperature range is calculated for a ZBLAN glass. The so-calculated ΔG is compared with the result of other heoretical approaches and experimental data. We can see from the result that the expression with the consideration of constant ΔC_P works well in the entire undercooling for ZBLAN glass forming system. So we can say that the specific heat difference is being constant in the entire undercooling for ZBLAN glass.

1 illus, 2 tables, 34 ref

042508   CHAUDHARY P D, PATEL V N, RANA V A, GADANI D H (Physics Dep, Gujarat Univ, Ahmedabad - 380 009, Email: dhgadani@yahoo.com) : Dielectric properties of soil mixed with urea fertilizer over 20 Hz to 2 MHz frequency range. Indian J Pure Appl Phys 2020, 58(6), 455-64.

The dielectric properties of sandy soil for various moisture contents of distilled water and Urea-fluid solutions in soil are estimated in the lower frequency range from 20 Hz to 2 MHz using precision LCR meter. The spectra of complex permittivity e*(ω), loss tangent tan δ(ω), electrical conductivity σ*(ω), and complex impedance Z*(ω) plane plots of these soil-fluid system have been investigated for various moisture contents of different concentrations of Urea solution in the soil samples. The dielectric constant and dielectric loss of the soil increase with increase in moisture content of different concentrations of Urea solution in the soil. The dielectric constant and dielectric loss of the soil increases significantly with the decrease in frequency over the given frequency range. The complex impedance plane (Zʹ versus Zʺ) plot separates electrode polarization and bulk material phenomena, which can also be observed in the dielectric loss tangent peaks.

10 illus, 2 tables, 32 ref

042507   SHINDE J B , RANDER D N , KANSE K S, JOSHI Y S, KUMBHARKHANE A C (Electronics Dep, Lal Bahadur Shastri Mahavidyalaya, Dharmabad - 431 809, Email: yjosh@rediffmail.com) : Dielectric dispersion study of binary mixtures of methyl ethers with water at 298.15 K using frequency domain technique. Indian J Pure Appl Phys 2020, 58(6), 448-54.

A precision LCR meter along with a liquid dielectric cell have been used to measure the capacitance and resistance of the binary mixtures of methyl ethers with water at 298.15 K in the frequency range of 20 Hz to 2 MHz. The measured values are used to compute the complex dielectric permittivity ε*(ω). The parameters like complex electrical modulus M*(ω), complex electrical conductivity σ*(ω) and loss tangent (tan δ) are obtained from the complex dielectric permittivity values of the samples. The values of excess dielectric permittivity of the samples are calculated using the respective static dielectric permittivity values. The refractive indices of all the samples were measured using Abbe’s refractometer at 298.15 K. All these parameters are used to gain insight into the concentration dependent variation in dielectric and electrical properties of the binary mixtures. A dominance of electrode polarization effect in the lower frequency region is observed for all the samples studied here.

9 illus, 19 ref

042506   MODI F M, GADANI D H, RANA V A (Physics Dep, Gujarat Univ, Ahmedabad - 380 009, Email: dhgadani@yahoo.com) : Estimation of sea water salinity from dielectric measurements: Effect of temperature. Indian J Pure Appl Phys 2020, 58(6), 439-47.

Dielectric measurements have been carried out for distilled water and saline water solutions of salinities 10000, 20000, 30000, 40000 ppm, as well as sea water of Diu beach area, using Anritsu Shockline Vector Network Analyzer (VNA, model no: MS46322A) in the frequency range from 1 GHz to 20 GHz, over the temperatures of 20 °, 30 ° and 40 °C. From the measured values of dielectric constant and dielectric loss, the values of tanδ, conductivity and emissivity of water solutions have been calculated. The variation in dielectric properties of water with salinity and temperature of measurement is compared with values calculated using Stogryn equations as well as Klein and Swift model and results are found to be in good agreement with corresponding values. From the dielectric loss values and the emissivity values of distilled water and saline water solutions at certain fixed frequencies, the salinity of sea water collected from Diu beach has been estimated to be 36,327 ppm which agrees very well with the physicochemical analysis report of laboratory.

10 illus, 3 tables, 14 ref

042505   GROZDANOV D N, FEDOROV N A, KOPATCH Y N, RUSKOV I N, DABYLOVA S B, ALIYEV F A, SKOY V R, HRAMCO C, TRETYAKOVA T Y, KUMAR A, GANDHI A, SHARMA A, WANG D, SAKHIYEV S K, TANGRA (Institute for Nuclear Research and Nuclear Energy (INRNE), BAS, Sofia, Bulgaria, Email: dgrozdanov@mail.ru) : Response function of a BGO detector for γ-rays with energies in the range from 0.2 MeV to 8 MeV. Indian J Pure Appl Phys 2020, 58(5), 427-30.

This work is devoted to determination of the response function of a BGO detector of γ-rays, which is used in experiments aimed at investigation of inelastic scattering of neutrons with energies of 14.1 MeV on various nuclei. A function is constructed to describe the Monte-Carlo simulated response of a gamma-detector, which allows taking into account all possible mechanisms of interaction of γ-rays with matter, as well as the geometric parameters of the detector. For all components of the function, an analytical form of their energy dependencies is selected and its parameters are determined in the case of registration of γ-quanta with energies in the range from 0.2 MeV to 8 MeV.

3 illus, 7 ref

042504   CHOUDHARY M, SHARMA A, GANDHI A, SINGH N, KUMAR A (Physics Dep, Banaras Hindu Univ, Varanasi - 221 005, Email: ajaytyagi@bhu.ac.in) : Study of pre-equilibrium contributions in proton spectra of ⁵⁹Co(n,xp) reaction using TALYS-1.9. Indian J Pure Appl Phys 2020, 58(5), 423-6.

In the present study we have calculated the proton spectra of ⁵⁹Co(n,xp) using TALYS-1.9. TALYS uses all major reaction mechanisms like compound, pre-equilibrium and direct reactions. The contribution from compound nuclear reaction is calculated using optical model calculations. For pre-equilibrium contributions we have used two particle exciton model. The results from the present work suggests the presence of significant pre-equilibrium emission components in the ⁵⁹Co(n,xp) system within the range of incident projectile energies from 37.5 to 62.7 MeV.

7 illus, 1 table, 10 ref

042503   ABBAS S A , USMANI A A , RAHAMAN U, IKRAM M (Physics Dep, Aligarh Muslim Univ, Aligarh - 202 002, Email: urahaman@myamu.ac.in) : Towards a consistent understanding of the exotic nucleus ¹⁴ ₄₂Si ₂₈. Indian J Pure Appl Phys 2020, 58(5), 418-22.

The issue of magicity of ₁₄ ⁴²Si ₂₈ has been a contentious one. Fridmann et al., through studies of two-proton knockout reaction ₁₆ ⁴⁴Si ₂₈ ⟶  ₁₄ ⁴²Si ₂₈, presented strong evidence in support of magicity and sphericity of ₁₄ ⁴²Si ₂₈. However in complete conflict with this, Bastin et al., gave equally strong empirical evidence, to show that the N = 28 magicity had completely collapsed in ₁₄ ⁴²Si ₂₈ to make it well deformed. The consensus at present though is in favour of the validity of the latter experiment. However, our QCD based theoretical model supports the result of Fridmann experiment. They had explored the amazing persistence of the unique exotic nucleus ₁₄ ⁴²Si ₂₈ as a stable structure within the nucleus ₂₀⁴⁸Ca ₂₈; even after stripping off six-protons through the isotonic chain: ₂₀⁴⁸Ca ₂₈ ⟶₁₈⁴⁶ Ar ₂₈ ⟶ ₁₆⁴⁴S₂₈ ⟶ . Thus it is the novel and unexpected stability of proton shell closure at Z=14 in ₁₄ ⁴²Si ₂₈, which is playing such a dominant role in ensuring its magicity, while the neutron magic number N = 28, goes into hiding or actually disappears. Recently, SAA has shown that the fusion experiment of a beam of halo nucleus ⁶He with the target nucleus 238U , actually provided strong evidence that the “core” of the halo nucleus has the structure of a tennis-ball (bubble) like nucleus, with a “hole” at the centre of its density distribution. This provides us with clear-cut support for our Quantum Chromodynamics based model of clusters of tritons in neutron-rich nuclei. Here we show that our QCD based model, provides support to Fridmann et al. , showing that, ₁₄ ⁴²Si ₂₈ has a spherically magic structure of 14 ₃¹H₂ (14-tritons) with a tennis-ball (bubble) like structure with “hidden” N=28 neutrons.

3 illus, 13 ref

042502   JOSE T A, SANTHOSH K P (Kannur Univ, Payyanur - 670 327, Email: drkpsanthosh@gmail.com) : Competition between alpha and heavy cluster decay in superheavy element ²⁹⁶Og. Indian J Pure Appl Phys 2020, 58(5), 415-7.

Systematic study of superheavy nuclei ²⁹⁶Og and its possibilities to emit alpha particle and heavier clusters are studied using Modified Generalized Liquid Drop Model (MGLDM) with Q value dependent preformation factor. Half-lives and branching ratio of all possible cluster emission of ²⁹⁶Og is checked and only those cluster which are within the experimental half-lives limit (less than 10³⁰s) and branching ratio limit (down to 10^-19) are considered. Among this, ⁸⁸Kr is found to be the most probable heavy cluster, leading to doubly magic ²⁰⁸Pb daughter nuclei, with half-lives comparable with alpha decay half-lives. Thus the role of doubly magic daughter nuclei in cluster decay is highlighted here. Again the decay modes of ²⁹⁶Og are also studied by comparing alpha decay half-lives using MGLDM with spontaneous fission half-lives proposed by Bao et al., and from this, it is found that for superheavy element ²⁹⁶Og, decays by 3 alpha chains followed by spontaneous fission. We hope that this study would help when this emission is experimentally detected in near future.

1 illus, 1 table, 21 ref

042501   BISWZS S, CHAKRABORTY A, JHIGAN A, ARORA D, BEHERA B R, BISWAS R, DEB N K, GHUGRE S S, GIRI P K, GOLDA K S, KAUR G, KUMAR A, KUMAR M, MUKHERJEE B, NAYAK B K, PARIHARI A, RAI N K, RAI S, RAUT R, SAHU R N, SINHA A K (Physics Dep, Siksha Bhavana, Santiniketan - 731 235, Email: anagha.chakraborty@visvabharati.ac.in) : Quasi-elastic scattering measurements of the ²⁸Si + ¹⁴²Nd system at back-angle. Indian J Pure Appl Phys 2020, 58(5), 409-14.

The barrier distribution of a system can be extracted from excitation function data obtained either through fusion reaction or through quasi-elastic scattering measurement. In the present work, the quasi-elastic excitation function has precisely been measured at back angle for the ²⁸Si + ¹⁴²Nd system at energies around the Coulomb barrier and the corresponding experimental barrier distribution has been extracted. The experimental data has been interpreted in the frame work of the coupled channel calculations which include couplings to different possible modes of excitations of the interacting target-projectile combination. The possible effect of the nature of projectile excitations on the derived barrier distribution has been presented.

5 illus, 1 table, 21 ref

042500   SALMA IBRAHIM R V, MUSTHAFA M M , MIDHUN C V, SWAPNA LILY CYRIAC S L, SAJEEV S (Physics Dep, Calicut Univ, Kerala - 673 635, Email: rv.salma@gmail.com) : Measurement and analysis of photonuclear reactions on thick target samples of biological importance. Indian J Pure Appl Phys 2020, 58(5), 404-8.

A novel method for quantification of trace elements in herbal samples using photon activation analysis is reported. Seven trace elements have been detected and their concentrations have been estimated from residue yields after the photo-nuclear reaction. This method can complement the conventional neutron activation analysis for trace elemental detection. The data is useful for setting referral standards for quality assurance of herbs and herbal formulations commercially available for therapeutic purposes. This is a relatively simple, novel and sensitive method for trace elemental analysis which can be scaled to suit industrial and statutory requirements of standardization and quality control.

2 illus, 2 tables, 30 ref

042499   NAVEYA G, KUMAR S S, PHILOMINRAJ S I A, STEPHEN A (Nuclear Physics Dep, Madras Univ, Chennai - 600 025, Email: stephen_arum@hotmail.com) : Alpha-decay chains of Z=122 superheavy nuclei using cubic plus proximity potential with improved transfer matrix method. Indian J Pure Appl Phys 2020, 58(5), 397-403.

The alpha decay chain properties of Z = 122 isotope in the mass range 298£ A £ 350, even-even nuclei, are studied using a fission-like model with an effective combination of the cubic plus proximity potential in the pre and post-scission regions, wherein the decay rates are calculated using improved transfer matrix method, and the results are in good agreement with other phenomenological formulae such as Universal decay law, Viola-Seaborg, Royer, etc. The nuclear ground-state masses are taken from WS4 mass model. The next minimum in the half-life curves of the decay chain obtained at N=186,178 & 164 suggest the shell closure at N=184, 176 & 162 which coincides well with the predictions of two-centre shell model approach. This study also unveils that the isotopes ^{298-300, 302, 304-306, 308-310, 312,314}122 show 7a, 5a, 4a, 3a, 2a and 1a decay chain, respectively. All the other isotopes from A = 316 to 350 may undergo spontaneous fission since the obtained SF half -lives are comparatively less. The predictions in the present study may have an impact in the experimental synthesis and detection of the new isotopes in near future.

2 illus, 2 tables, 31 ref

042498   MEHTA M, SINGH N L , MAKWANA R , SUBHASH P V , SURYANARAYANA S V , PARASHARI S , CHAUHAN R , SINGH R K, NAIK H , MUKHERJEE S , SONIB B , KHIRWADKARA S , VARMUZAF J, KATOVSKY K (Physics Dep, The M S University of Baroda 390 002, Gandhinagar - 382 428, Email: mayur@ipr.res.in) : Measurement of (n,γ) reaction cross section of ¹⁸⁶W-isotope at neutron energy of 20.02±0.58 MeV. Indian J Pure Appl Phys 2020, 58(5), 392-6.

The cross-section of ¹⁸⁶W(n,γ)¹⁸⁷W reaction has been measured at an average neutron energy of 20.02±0.58 MeV by using activation technique. The ²⁷Al(n,α)²⁴Na and ¹¹⁵In(n,n´)^115mIn reactions have been used for absolute neutron flux measurement. Theoretically the reaction cross-sections have been calculated by using the TALYS-1.9 code. The results from the present work and the EXFOR based literature data have been compared with the evaluated data and calculated data from TALYS-1.9 code.

5 illus, 2 tables, 25 ref

042497   MAHATO A , GIRI P K , SINGH D, SHARMA N , LINDA S B , KUMAR H , TALI S A , DEB N K, ANSARI M A, KUMAR R, MURALITHARD S, SINGH R P (Physics Dep, Central Univ of Jharkhand, Ranchi - 835 205, Email: dsinghcuj@gmail.com) : Effect of projectile breakup in the system ¹⁹F + ¹⁵⁴Sm. Indian J Pure Appl Phys 2020, 58(5), 386-91.

An attempt was made to understand the role of various entrance channel parameters on incomplete fusion dynamics by the measurements of excitation functions of evaporation residues populated via complete and incomplete fusion dynamics in the system ¹⁹F + ¹⁵⁴Sm at projectile energy ≈ 4-6 MeV/A. The stacked foil activation technique followed by offline gamma ray spectrometry was employed in these measurements. The measured excitation functions of various evaporation residues populated have been analyzed within the framework of statistical model code PACE-4. It has been observed that the measured excitation functions of xn and pxn emission channels agree well with the theoretical predictions of PACE-4. On the other hand, the measured excitation functions of α-emission channels have been found significantly enhanced over their theoretical predictions. This enhancement may be attributed to the incomplete fusion of the projectile ¹⁹F as the calculations for incomplete fusion are not included in statistical model calculations. The incomplete fusion fraction has been deduced from the present measurements. Further, a systematic study has also been performed, which shows that the incomplete fusion increases significantly with entrance channel mass asymmetry at low projectile energy, differently for different projectiles.

3 illus, 32 ref

042496   SIDDAVATAM A P I , PATIL A T, VAIDYA P P (V E S Institute of Technology, Chembur - 400 074, Mumbai, Email: ajit.patil@ves.ac.in, pp.vaidya@ves.ac.in) : A pulse generation system based on new method for testing performance of highresolution nuclear spectroscopy systems. Indian J Pure Appl Phys 2020, 58(5), 380-5.

The paper presents a design and construction of uniform amplitude pulse generator for testing Differential Non-Linearity (DNL) of high-resolution nuclear spectroscopy systems. The paper describes two methods based on two new techniques called DAC Interpolation and Analog Multiplexer based design. A prototype of DAC interpolation technique has been designed and tested. **The method based on analog multiplexer and chain of resistors is simulated and the results of which is reported in the paper. The systems produce pulses with step size of 10 microvolt (µV), making them capable for calibrating spectroscopy systems with the resolution as high as 13-bit (8K). The systems are designed using commercially available components. The pulse generation system provides import substitute for commercially available imported models.

8 illus, 1 table, 9 ref

042495   OJHA A, GUPTA S , SHUAIB M , SINGH B P, PRASAD R (Physics Dep, Agra Coll, Agra - 282 002, Email: iwa2008@rediffmail.com)) : Variation of ICF strength function with projectile energy for ¹²C + ¹⁶⁵Ho system at E_lab ≤ 7MeV/A. Indian J Pure Appl Phys 2020, 58(5), 376-9.

During the last few decades, research in heavy-ion induced nuclear reactions has opened numerous fields, in its theoretical and experimental domains. At energies, from near the Coulomb barrier to well above it, the complete fusion (CF) and incomplete fusion (ICF) reactions compete with each other. The relative contribution of these processes depends on various entrance channel parameters. In order to study the dependence of CF and ICF reaction dynamics on various entrance channel parameters, comparative studies with different parameters of the statistical model codes have been done. In this paper, an attempt has been made to study the dependence of incomplete fusion strength function on incident energy for ¹²C + ¹⁶⁵Ho system at energies ≤ 7 MeV/A. The analysis of data has been done within the frame work of statistical model code PACE4, which do not take ICF into account; and thus predicts cross-section values only due to complete fusion process. For the present reaction system, the excitation functions (EFs) of xn/pxn channels, predicted by PACE4 code, well reproduces the experimentally measured values, indicating their production via CF process only. However, for α and 2α-emitting channels, calculated EFs through PACE4 code underpredict the experimentally measured cross-sections by »25-30%, in general. The enhancement of experimental cross-sections for α and 2α-emitting channels as compared to the PACE4 predictions, indicates that the major contribution of their production comes from the ICF of ¹²C, if it breaks up into ⁸Be and α-fragments, and one of the fragments fuses with the target nucleus. The incomplete fusion strength function (F_ICF), which gives relative importance of ICF processes over CF process has also been deduced and is found to depend sensitively on beam energy.

8 illus, 10 ref

042494   GIRI P K, MAHATO A , SINGH D, LINDA S B , KUMAR H , TALI S A , ANSARI M A , KUMAR R , MURALITHAR S, SINGH R P (Physics Dep, Central Univ of Jharkhand, Ranchi - 835 205, Email: dsinghcuj@gmail.com) : Disentangling of incomplete fusion dynamics at low energies ≈ 4-6 MeV/A. Indian J Pure Appl Phys 2020, 58(5), 371-5.

An experiment has been performed for the measurements of forward recoil range distributions (FRRDs) of evaporation residues (ERs) using ¹⁶O beam on the target ¹⁴⁸Nd to explore the incomplete fusion (ICF) dynamics at low projectile energy ≈ 4-6 MeV/A. In the present work, FRRDs of ERs ^159,158Er(xn), ^160g,159Ho(pxn), ^157,155Dy(αxn) and 155Tb(αpxn) have been measured. The measured FRRDs of ERs have been compared with their theoretical mean ranges, calculated using code SRIM. These present results obtained from FRRDs measurements show that full and partial linear momentum transfer components are involved. This indicates that the ERs populated through α-emission channels are not only produced via complete fusion, but also through incomplete fusion dynamics. The present analysis indicates that the incomplete fusion contribution increases with projectile energy. This increment in incomplete fusion contribution is due to the increase in breakup probability of projectile ¹⁶O into ¹²C + ⁴He/ α with projectile energy.

5 illus, 20 ref

042493   SINGH U , SINGH M K, SINGH V (Physics Dep, G L A Univ, Mathura - 281 406, Email: singhmanoj59@gmail.com) : Projectile multifragmentation study in the interaction of ⁸⁴Kr with nuclear emulsion detector at relativistic energy. Indian J Pure Appl Phys 2020, 58(5), 368-70.

A heavy-ion collision provides a unique opportunity to study the state of matter under extreme conditions of density and temperature. Nuclear fragmentation is an important experimental phenomenon in nucleus-nucleus collision at relativistic energy, since it carries the information about emission mechanism, phase transition of the nuclear matter as well as equation of state. The interesting feature of heavy-ion interactions is the variation of reaction properties with collision geometry. Multifragmentation is one of the most important aspects of heavy ion collision. This work focus on the emission characteristics of the intermediate mass fragments produced in the interaction of ⁸⁴Kr with nuclear emulsion at incident kinetic energy of 1 GeV per nucleon.

5 illus, 9 ref

042492   JOSHI P K (Homi Bhabha Centre for Science Education, Mumbai - 400 088, Email: pkjoshi@tifr.res.in) : Evaluation of nuclear structure data and its spin-offs. Indian J Pure Appl Phys 2020, 58(5), 363-7.

Evaluation of nuclear structure data is a world wide effort to standardize the published nuclear data. This standardization led to generation of table of isotopes, Nuclear Data sheets, Nuclear Wallet Cards etc. This paper deals with two aspects of evaluation of nuclear structure data. First, the problems arising out of some of the recent publications and how to tackle them at pre-publication stage. Second, there is large amount of experimental data available on the NNDC site¹ . Of these data the half-life values, spin and parity is the most important set of values to understand the nucleon-nucleon interaction within a given nucleus. However, it is observed in our work that the quantum of half-life, spin and parity values measured, in comparison to the number of excited states, in any given nuclei, is very low. Thus, indicating that very few experimental results are available in terms of half-life measurements, spin measurements and determination of parity. This survey besides being an indicator of the quantum of measurements carried out can also be a guide to future experimentalists by highlighting the areas of nuclear chart where measurements are fewer in number.

1 illus, 8 tables, 19 ref

042491   FEDOROV N A, DASHKOV I D , GROZDANOV D N, KOPATCH Y N, RUSKOV I N , SKOY V R , TRETYAKOVA T Y (Joint Institute for Nuclear Research, Dubna, Russia, Email: na.fedorov@physics.msu.ru) : Investigation of 14.1 MeV neutrons interaction with C, Mg, Cr. Indian J Pure Appl Phys 2020, 58(5), 358-62.

This paper is dedicated to n+¹²C, n+²⁴Mg, n+⁵²Cr -reactions investigation at 14.1 MeV neutron energy. Characteristics of these reactions have been calculated using TALYS code to estimate perspectives of using of this code in data interpretation in the TANGRA project. This project is performed in Frank Laboratory of Neutron Physics (FLNP JINR) to investigate properties of (n,xγ)-type reactions, important for fundamental and practical applications.

4 illus, 2 tables, 25 ref

042490   RAMA S P, NAIRA J , SURYANARAYANA S V, DHANU K S , NAIK H, GANESAN S (Instrumentation Dep, V E S Institute of Technology, Mumbai - 400 074, Email: sangeeta.prasannaram@ves.ac.in) : Measurement of ¹⁰⁰Mo (n, 2n) ⁹⁹Mo reaction cross section and covariance analysis using extended unscented transformation technique at the incident neutron energy of 13.9 MeV. Indian J Pure Appl Phys 2020, 58(5), 351-7.

In this paper, the measurement and covariance analysis of the cross section of ¹⁰⁰Mo (n, 2n) ⁹⁹Mo reaction, with the ¹⁹⁷Au (n, 2n)¹⁹⁶ Au reaction being used as the monitor, at the incident neutron energy of 13.9 MeV is reported. The ³H (d, n) ⁴He nuclear reaction is used as the neutron source. The experiment was performed at the Purnima neutron facility, BARC. The method of activation with off-line -ray spectrometry is used. The covariance analysis of the ¹⁰⁰Mo (n, 2n) ⁹⁹Mo reaction is also performed, for the first time, using the extended unscented transformation (EUT) technique¹, which is an extension of unscented transformation (UT) technique², for the determination of partial uncertainties arising due to attributes in combination with the micro-correlation technique of Geraldo and Smith³. The present results obtained for ¹⁰⁰Mo (n, 2n) ⁹⁹Mo reaction cross section are found to be in good agreement with EXFOR data and the theoretically calculated value using the TALYS 1. 8 code. Comparisons with the data in the available basic evaluated nuclear data libraries, such as ENDF/B-VIII.0, JEFF-3.3, JENDL-4.0, ROSFOND-2010, CENDL-3.1 and TENDL 2017 are also presented and discussed.

2 illus, 6 tables, 24 ref

042489   CHAVAN K , VAIDYA P P, NAIR J M (Instrumentation Dep, Mumbai Univ, Mumbai - 400 074, Email: kanchan.chavan@ves.ac.in) : High resolution nuclear timing spectroscopy system based on new method of free running ramp and tracking ADCs. Indian J Pure Appl Phys 2020, 58(5), 346-50.

The paper describes a new method for high resolution nuclear timing spectroscopy system using tracking ADCs and free running ramp to give the timing resolution of few ps over wide dynamic range of time interval extending up to few µs. The method makes use of tracking ADCs with 16 bit resolution with low conversion time of nearly 1 µs along with a free running ramp which is given as input to the two ADCs. Both the ADCs and ramp are designed to track their characteristics in order to neutralize the errors due to drift in their characteristics and hence complex system of spectrum stabilization is not required. ADC1 digitizes ramp input at the arrival of START pulse and ADC2 digitizes ramp input at the arrival of STOP pulse. The difference between digital codes of these ADCs is a measure of time interval between START and STOP pulses. New system doesn’t require delay and hence biased amplifier. System has dead time of 1 µs and spectrum stabilization is easy.

5 illus, 8 ref

042488   BEHERA N , BHAT G H , NAIK Z, PALIT R , SUND Y, SHEIKH J A (Sambalpur Univ, Burla - 768 019, Email: z.naik@suniv.ac.in) : High spin structure of ⁸²Sr using triaxial projected shell model. Indian J Pure Appl Phys 2020, 58(5), 342-5.

Study of N≈Z nuclei in mass A ̴80 region, which is in the transitional region, is of interest due to the existence of abundant nuclear structure phenomena and this mass region is often characterized by shape co-existence. In present work, the multi-quasiparticle triaxial projected shell model (TPSM) approach is employed to study the high spin structures and to depict γ deformation in ⁸²Sr. TPSM results for the yrast band and γ band-energies are compared with known experimental energies. The possibility of a 2γ-band is also predicted. The change in staggering phases for the γ band as a result of configuration mixing is also discussed.

4 illus, 14 ref

042487   MANJUNATHA H C, SRIDHAR K N, SOWMYA N, (Physics Dep, Government Coll for Women, Kolar - 563 101, Email: manjunathhc@rediffmail.com) : Evaporation residue cross section to synthesize superheavy element Z=119. Indian J Pure Appl Phys 2020, 58(5), 336-41.

The evaporation-residue cross section σ_EVR of fusion reactions depend on the projectile-target combinations and the incident energy. A detail theoretical study is useful before the synthesis of more isotopes of super heavy nuclei Z=119. We have studied the evaporation-residue cross sections for possible projectile-target combinations to synthesis the superheavy nuclei with Z=119. We have studied the dependence of evaporation residue cross section with that of mass number of the target, product of atomic numbers of projectile and target (Z₁Z₂), fusion barrier height (V_b) and fusion barrier width (R_b).  After the detailed analysis, we have identified the most probable projectile-target combinations. The identified projectile-target combinations to synthesis superheavy nuclei ^295-296119 are ⁴⁵Sc+^250,251Cf. We hope that our predictions guide the future experiments in the synthesis of super heavy nuclei ^295-296119.

8 illus, 42 ref

042486   KAUR G, SHARMA M K (Thapar Institute of Engineering and Technology, Patiala - 147 004, Email: gurjitsaini2505@gmail.com) : Relative emergence of fission and quasi-fission in Z=116 superheavy nucleus. Indian J Pure Appl Phys 2020, 58(5), 331-5.

The fusion and subsequent decay analysis of Z=116 superheavy nucleus formed via ⁴⁸Ca+²⁴⁸Cm→²⁹⁶Lv^*, ⁵⁰Ti+²⁴⁴Pu→²⁹⁴Lv^*,and ⁵⁸Fe+²³²Th→²⁹⁰Lv^* reactions is carried out using extended ℓ-summed Wong model and dynamical cluster decay model (DCM), respectively. First of all, the experimentally available fusion-fission (A/2±20) data is adequately addressed for ²⁹⁶Lv^* and ²⁹⁴Lv^* superheavy nuclei using extended ℓ-summed Wong model and the predictions are made for fusion-fission excitation function of ²⁹⁰Lv^* nucleus. It is observed that with decrease in mass-asymmetry (η), the contribution of fusion-fission component decreases. This drop is steeper for ⁵⁰Ti to ⁵⁸Fe as compared to that for ⁴⁸Ca to ⁵⁰Ti. The calculated values of compound nucleus formation probability (P_CN) are highest for ⁴⁸Ca followed by ⁵⁰Ti and ⁵⁸Fe. Finally, the mass distribution of decay fragments is studied for ²⁹⁶Lv^*, ²⁹⁴Lv^*, and ²⁹⁰Lv^* nuclei using DCM at near barrier energies. A valley in A_CN/2 region results in asymmetric mass distribution for ²⁹⁶Lv^* which becomes relatively symmetric for the lighter isotope ²⁹⁰Lv^*.

5 illus , 19 ref

042485   SINGH N, GANDHI A, SHARMA A, CHOUDHARY M, KUMAR A (Physics Dep, Banaras Hindu Univ, Varanasi - 221 005, Email: ajaytyagi@bhu.ac.in) : Excitation functions of (n,p) and (n,2n) reactions of tantalum, rhenium, and iridium in the neutron energy range up to 20 MeV. Indian J Pure Appl Phys 2020, 58(4), 314-8.

The excitation functions for (n,p) and (n,2n) reactions up to 20 MeV on Tantalum, Rhenium, and Iridium have been calculated using the TALYS-1.9 nuclear reaction model code. Different level density models have been used to get a good agreement between the calculated and measured data. In the present work, we have carried out the TALYS-1.9 calculations to quantitatively understand the experimental data by optimizing input parameters for ¹⁸¹Ta(n,p)¹⁸¹Hf, ¹⁸¹Ta(n,2n)¹⁸⁰Ta, ¹⁸⁵Re(n,p)^185mW, ¹⁸⁵Re(n,2n)¹⁸⁴Re,¹⁹¹Ir(n,p)¹⁹¹Os and ¹⁹¹Ir(n,2n)¹⁹⁰Ir. Theoretical results have been compared with the experimental data (taken from the EXFOR database) up to 20 MeV. Also, the results have been compared with the ENDF/B-VIII.0 and TENDL-2015 evaluated data.

6 illus, 41 ref

042484   DUTTA S, QI C, AHMED I, RIZVI I A,KUMAR R (Physics Dep, Aligarh Muslim Univ, Aligarh - 202 002, Email: sunilduttamu@gmail.com) : Large-scale shell-model calculations near mass region 100-130. Indian J Pure Appl Phys 2020, 58(4), 308-13.

In this work, we have presented a microscopic shell-model description of the structure and collective behavior of intermediate-mass nuclei around doubly magic 100Sn and 132Sn nuclei. The Sn-isotopes lie between the two doubly magic nuclei and cover a range from exotic proton-rich N=Z nuclei to exotic neutron-rich nuclei with N/Z > 1.6. The results obtained using BIGSTICK code for the low-level excitation states and transition probabilities for the studied Sn and Ba isotopic chains have been discussed in the radiance of available experimental data. We have used 100Sn as a core for all the studied isotopes with the same valence space (i.e. 1d_5/2, 2s_1/2, 1d_3/2, 0g_7/2, 0h_11/2 or ‘sdgh’) for both protons (Z) and neutrons (N) between 50 and 82. These calculations are performed by means of globally optimized monopole effective interaction for the sdgh-shell.

10 illus, 14 ref

042483   KUMAR S , SINGHA S , SINGH B, A K JAIN A K (Physics Dep, Akal Univ, Talwandi Sabo - 151302, Email: sukhjeet.dhindsa@gmail.com) : Systematics of alpha decay hindrance factors in doubly-even nuclei. Indian J Pure Appl Phys 2020, 58(4), 304-7.

In present work, we have calculated the hindrance factors of 182 even-even alpha emitters using Preston’s formulation of alpha decay probabilities and presented HFs systematics of 1^- and 3^- states in reflection asymmetric even-even quadruple-octupole deformed nuclides (A~216-230). The calculated HFs of both 1^- and 3^- states decrease with reduction in neutron number and this decrease is attributed to onset of intrinsic reflection asymmetry. There is a trend reversal for 1^- states at N=132 (²¹⁸Ra) and N=134 (²²⁰Rn), which might be a possible indication of departure from static octupole deformation. Similarly, HFs systematics is discussed for ^224-230Th and ^232-236U isotopic chains along with 2⁺ states observed in daughter nuclei in N=132-146 isotonic chains.

2 illus, 10 ref

042482   SHARMA, DEVI R (Physics Dep, Jammu Univ, Jammu - 180 006, Email: rani_rakwal@yahoo.co.in) : Systematic study of nuclear structure properties of proton-rich even-even tellurium isotopes with the gogny energy density functional. Indian J Pure Appl Phys 2020, 58(4), 298-303.

 The ground state nuclear structure properties of the proton rich even-even tellurium isotopes are studied by using Gogny energy density functional within the framework of Hartree-Fock-Bogoliubov (HFB) method. The HFB equations are solved by using the axial cylindrical transformed deformed harmonic oscillator basis. The full parameterization of Gogny energy density functional is employed in the present study. The evolution of the neutron density distributions with an increase in neutron number is studied and emergence of various nuclear structure phenomena is investigated. Besides this, the ground state nuclear structure properties such as nuclear multipole moments, deformation parameters, binding energies, pairing energies, root mean square radii and charge radii are obtained for the even-even proton-rich tellurium isotopes. The theoretical results on the nuclear ground state properties are compared with the available experimental data and good agreement is found.

6 illus, 1 table, 26 ref

042481   SATHEESH B (Physics Dep, Mahatma Gandhi Govt Arts Coll, New Mahe - 673 311, Email: satheesh.b4@gmail.com) : Study of entrance channel effects on pre-equilibrium emissions in proton and alpha induced reactions on ⁶⁴Ni: Basic pre-equilibrium parameters. Indian J Pure Appl Phys 2020, 58(4), 294-7.

The effect of entrance channel on the relative strength of pre-equilibrium emission, basic pre-equilibrium parameters, excitation functions for proton and alpha induced reactions on ⁶⁴Ni have been analyzed over the energy range from threshold up to 40 MeV. The results have been compared with the theoretical cross-sections calculated by means of the code EMPIRE3.2.3-MALTA and TALYS 1.6

4 illus, 12 ref

042480   P TICHÝ , J ADAMA, A A BALDINA, P CHUDOBAB , W I FURMANA , S A GUSTOVA , J H KHUSHVAKTOVA,, A KRÁSAG , M MAJERLE , I I MAR’IN , A A SOLNYSHKIN , M SUCHOPÁRH , J SVOBODA, O SVOBODA , S I TYUTYUNNIKOV , J VRZALOVÁ, V WAGNER , L ZÁVORKAI , M ZEMAN (Czech Technical Univ in Prague, B?ehová 7, Prague 11519, Czech Republic, Email: tichy@jinr.ru) : Monitoring mixed neutron-proton field near the primary proton and deuteron beams in spallation targets. Indian J Pure Appl Phys 2020, 58(4), 282-93.

At the Joint Institute for Nuclear Research (JINR) we are involved in the Accelerator-Driven-System (ADS) research. We perform experiments with assemblies composed of a spallation target and a subcritical blanket irradiated with high-energy proton or deuteron beams that generate high-energy neutron fields by spallation and fission reactions. In this paper, three uranium assemblies are presented: Energy plus Transmutation (E+T), QUINTA and BURAN. We discuss the results of the E+T and QUINTA irradiations by 1.6 GeV deuterons and 660 MeV protons, respectively. We have focused on the regions close to the primary beam passage through the targets. The field has been measured using activation detectors of ²⁰⁹Bi, ⁵⁹Co, and ^natPb. Monte Carlo simulations using MCNPX 2.7.0 have been performed and compared to the experimental results. We discovered that the field intensity near the primary beam is very dependent on the precision of the accelerator beam settings. Therefore, a Monte Carlo-based study of the influence of the uncertainty of primary proton beam parameters on experimental result accuracy of the QUINTA assembly has been carried out. The usage of MCNPX 2.7.0 in the future BURAN irradiations has been assessed.

15 illus, 26 ref

042479   SHARMA I, GROVER N ,SHARMA M K (Thapar Institute of Engineering and Technology, Patiala - 147 004, Email: ishitasharma2222@gmail.com) : Complete and incomplete fusion cross-sections for ⁷ Li+¹¹⁹Sn reaction using different approaches. Indian J Pure appl phys 2020, 58(4), 277-81.

In reference to complete fusion (CF) and incomplete fusion (ICF) processes, the analysis of ⁷Li+¹¹⁹Sn reaction forming ¹²⁶I compound nucleus (CN) is carried out at incident energies spread across the Coulomb barrier. Firstly, the total fusion (TF) cross-sections are calculated using the Wong formula. Since, it overestimates the experimental data, so ℓ-summed Wong approach is employed to address the TF cross-section, which limits the contribution of partial waves up to ℓ _max value. Within ℓ-summed Wong model, the energy dependent selection function is used to separate out the contributions of CF and ICF from the TF cross-sections. This phenomenological selection function seems to give adequate distribution of CF and ICF cross-sections at higher energies. Beside this, the CF and ICF contributions are also separated out on the basis of angular momentum window and by using the energy correction formula. In the angular momentum distribution case, CF and ICF cross-sections are estimated in view of ℓ-windows, 0≤ℓ<ℓ_critical(for CF) and ℓ_critical≤ ℓ ≤ℓ_max(For ICF). Finally, in energy normalization case, the incident energy of ⁷Li beam (⁷Li→⁴He + ³H) is distributed among alpha and tritium fragments, and the ICF cross-sections for ³H+¹¹⁹Sn ICF channel are estimated using the ℓ-summed Wong model.

5 illus, 12 ref

042478   MANJUNATHA H C, SRIDHAR G R, GUPTA P S D, SRIDHAR K N, SRINIVAS M G, RAMALINGAM H B (Physics Dep, Government Coll for Women, Kolar - 563 101, Email: manjunathhc@rediffmail.com) : Decay modes of uranium in the range 203 < A < 299. Indian J Pure appl phys 2020, 58(4), 234-40.

In the present work, we have considered the total potential as the sum of the coulomb and proximity potential. We have used the recent proximity function to calculate the nuclear potential. The calculated logarithmic half-lives correspond to fission, cluster and alpha decay are compared with that of experiments. We also identified the most probable decay mode by studying branching ratios of these different decay modes. The competition between different decay modes such as fission, cluster radioactivity and alpha decay finds an important role in nuclear structure.

4 illus, 2 tables, 42 ref

042477   SONI B K, PARASHARI S, MUKHERJEE S, MAKWANA R, MEHTA M, CHAUHAN R, SURYANARAYANA S V, PASHA I, DANU L S, NAIK H, NAYAK B K, VARMUZA J, KATOVSKY K (Physics Dep, The M S Univ of Baroda, Vadodara - 390 002, Email: sonibhargav15@gmail.com) : Measurements of ¹⁸¹Ta(n,2n)¹⁸⁰Ta reaction cross-section at the neutron energy of 14.78 MeV. Indian J Pure appl phys 2020, 58(4), 228-33.

The cross-section of the ¹⁸¹Ta(n,2n)¹⁸⁰Ta reaction has been measured with respect to the ¹⁹⁷Au(n,2n)¹⁹⁶Au monitor reaction at the incident neutron energy of 14.78± 0.20 MeV, using neutron activation analysis and off-line γ-ray spectrometric technique. The present measurement has been done at the energy where discrepant measured results are available in the EXFOR data library. The result has been compared with evaluated data libraries JEFF-3.3 and ENDF/B-VII.1. The present result has also been supported by theoretical predictions of nuclear model code TALYS1.8 and TALYS-1.9. The uncertainty and the correlations among the measured cross-section has been studied using co-variance analysis.

3 illus, 3 tables, 23 ref