One-neutron stripping reactions of <Superscript>11</Superscript>Be and <Superscript>19</Superscript>C on light target

We have calculated the one-neutron absorption cross-section and the longitudinal momentum distribution of the core fragment coming out from the breakup of ¹¹Be and ¹⁹C on ⁹Be target at 63 MeV/A and 88 MeV/A beam energies respectively. The reaction mechanism is treated within the framework of the eikonal approximation. The effective range of the nuclear interaction between the core and the valence neutron within the projectile has been determined by comparing the predicted stripping cross-section with the recently measured one. The effective range for ¹⁹C has been found to be smaller than that for ¹¹Be. It qualitatively indicates that ¹⁹C is slightly more halo than ¹¹Be. The smaller width, predicted as well as measured, of the LMD of ¹⁸C than ¹⁰Be also strengthens this fact. The experimental data concerning the LMD of core fragments have been well represented.      

Three Flavor Neutrino Mixing and Dark Energy Above GUT Scale

Neutrino mixing lead to a non zero contribution to the dark energy of the universe. We assume that the neutrino masses and mixing arise through physics at a scale intermediate between Planck Scale and the electroweak scale. The mechanism of neutrino mixing is a possible candidate to contribute the cosmological dark energy. Quantum gravitational (Planck scale) effects lead to an effective SU(2) _L ×U(1) invariant dimension-5 Lagrangian involving neutrino and Higgs fields, which gives rise to additional terms in neutrino mass matrix. There additional term can be considered to be perturbation of the GUT scale bi-maximal neutrino mass matrix. We assume that the gravitational interaction is flavor. In this paper, we discuss the three flavor neutrino mixing and cosmological dark energy contributes due to Planck scale effects.     

The role of oxygen and hydrogen partial pressures on structural and optical properties of ITO films deposited by reactive rf-magnetron sputtering

Sn doped In₂O₃ films are deposited by rf-magnetron sputtering at 300 °C under Ar, Ar + O₂ and Ar + H₂ gas ambients. For the film prepared under argon ambient, electrical resistivity 6.5 × 10⁻⁴ Ω cm and 95% optical transmission in the visible region have been achieved optimizing the power and chamber pressure during the film deposition. X-ray diffraction spectra of the ITO film reveal (2 2 2) and (4 0 0) crystallographic planes of In₂O₃. With the introduction of 1.33% oxygen in argon, (2 2 2) peak of In₂O₃ decreases and resistivity increases for the deposited film. With further increase of oxygen in the sputtering gas mixture crystallinity in the film deteriorates and both the peaks disappeared. On the other hand, when 1.33% hydrogen is mixed with argon, the resistivity of the deposited film decreases to 5.5 × 10⁻⁴ Ω cm and the crystallinity remains almost unchanged. In case of reactive sputtering, the deposition rate is lower compared to that in case of non-reactive sputtering. HRTEM and first Fourier patterns show the highly crystalline structure of the samples deposited under Ar and Ar + H₂ ambients. Crystallinity of the film becomes lower with the introduction of oxygen in argon but refractive index increases from 1.86 to 1.9. The surface morphology of the ITO films have been studied by high resolution scanning electron microscopy.     

Effects of E2 and El-E2 Interference on Coulomb Dissociation of 19C

We investigate the effects of higher order multipole transitions, in particular electric quadrupole （E2） and El-E2 interference, on the Coulomb dissociation of 19 C within the framework of the first order eikonal approximation. The sensitivity of the total Coulomb breakup cross section and the longitudinal momentum distribution of the core fragment to these effects are checked. The breakup occurs predominately through the dipole transition and the contribution of E2 transition to the total cross section is found to be within the range from 1 to 3% of that of El. It is further observed that the El-E2 interference term contributes nothing to the integrated cross section. On the other hand, the longitudinal momentum distribution is observed to be insensitive to the E2 transition while the El-E2 interference introduces a small asymmetry in its shape.     

Electron and positron impact excitation of hydrogen from the initially excited 22S state to 32S and 32P states

The total and differential cross sections for the electron and positron impact excitation of hydrogen from its initially excited metastable 2²S state to 3²S and 3²P states are reported. A distorted-wave approximation theory is used for the calculation. The angular correlation parameters, Ly and alignment angle are also reported for 2²S-3²P excitation. For comparison, similar first Born results are also obtained. Interesting features are noted on comparing our distorted wave results with the first Born results as well as with the other available results forn ²S andn ²P (n=2,3) excitations from the ground 1²S state of hydrogen.     

Temperature dependent small-angle neutron scattering of CTABr—magnetic fluid emulsion

Small-angle neutron scattering studies have been carried out to check the structural integrity of citryltrimethylammonium bromide (CTABr) micelles in a magnetic fluid for different magnetic fluid concentrations at two different temperatures 303 and 333 K. It is found that the CTABr micelles grow with increasing magnetic fluid concentration and there is a decrease in the micellar size with increase in temperature.     

Efficient design of perovskite solar cell using mixed halide and copper oxide

Solar cells based on perovskites have emerged as a transpiring technology in the field of photovoltaic. These cells exhibit high power conversion efficiency. The perovskite material is observed to have good absorption in the entire visible spectrum which can be well illustrated by the quantum efficiency curve. In this paper, theoretical analysis has been done through device simulation for designing solar cell based on mixed halide perovskite. Various parameters have efficacy on the solar cell efficiency such as defect density, layer thickness, doping concentration, band offsets, etc. The use of copper oxide as the hole transport material has been analyzed. The analysis divulges that due to its mobility of charge carriers, it can be used as an alternative to spiro-OMeTAD. With the help of simulations, reasonable materials have been employed for the optimal design of solar cell based on perovskite material. With the integration of copper oxide into the solar cell structure, the results obtained are competent enough. The simulations have shown that with the use of copper oxide as hole transport material with mixed halide perovskite as absorber, the power conversion efficiency has improved by 6%.The open circuit voltage has shown an increase of 0.09 V, short circuit current density has increased by 2.32 m A/cm~2, and improvement in fill factor is 8.75%.     

Design and Development of Nano-Resolution Wireless Czochralski System for High Quality Crystal Growth Applications

Crystallography Reports - Remotely operated Czochralski puller, Automatic Crystal Puller System (ACPS) with a translation nano-resolution of 20 nm, is designed and developed for high quality...