Adiabatic Heavy Ion Fusion Potentials for Fusion at Deep Sub-barrier Energies

The fusion cross sections from well above barrier to extreme sub-barrier energies have been analysed using the energy (E) and angular momentum (L) dependent barrier penetration model ({\small{ELDBPM}}). From this analysis, the adiabatic limits of fusion barriers have been determined for a wide range of heavy ion systems. The empirical prescription of Wilzynska and Wilzynski has been used with modified radius parameter and surface tension coefficient values consistent with the parameterization of the nuclear masses. The adiabatic fusion barriers calculated from this prescription are in good agreement with the adiabatic barriers deduced from {\small{ELDBPM}} fits to fusion data. The nuclear potential diffuseness is larger at adiabatic limit, resulting in a lower $\hbar\omega$ leading to increase of "logarithmic slope" observed at energies well below the barrier. The effective fusion barrier radius and curvature values are anomalously smaller than the predictions of known empirical prescriptions. A detailed comparison of the systematics of fusion barrier with and without L-dependence has been presented.Comment: Revtex file of 6 pages and 3 eps figure

Event-based simulation of interference with alternatingly blocked particle sources

We analyze the predictions of an event-based corpuscular model for interference in the case of two-beam interference experiments in which the two sources are alternatingly blocked. We show that such experiments may be used to test specific predictions of the corpuscular model.Comment: FPP6 - Foundations of Probability and Physics 6, edited by A. Khrennikov et al., AIP Conference Proceeding

Investigation of Complex Impedance and Modulus Properties of Nd Doped 0.5BiFeO3-0.5PbTiO3 Multiferroic Composites

0.5BiNdxFe1-xO3-0.5PbTiO3 (x=0.05, 0.10, 0.15, 0.20) composites were successfully synthesized by a solid state reaction technique. At room temperature X-ray diffraction shows tetragonal structure for all concentrations of Nd doped 0.5BiFeO3-0.5PbTiO3 composites. The nature of Nyquist plot confirms the presence of bulk effects only for all compositions of Nd-doped 0.5BiFeO3-0.5PbTiO3 composites. The bulk resistance is found to decreases with the increasing in temperature as well as Nd concentration and exhibits a typical negative temperature coefficient of resistance (NTCR) behavior. Both the complex impedance and modulus studies have suggested the presence of non-Debye type of relaxation in the materials. Conductivity spectra reveal the presence of hopping mechanism in the electrical transport process of the materials. The activation energy of the composite increases with increasing Nd concentration and were found to be 0.28, 0.27, 0.31 and 0.32eV for x=0.05, 0.10, 0.15, 0.20 respectively at 200-275 oC for conduction process.Comment: 22 pages, 12 figures, 2 tables, 34 Referenc

Energy diffusion in hard-point systems

We investigate the diffusive properties of energy fluctuations in a one-dimensional diatomic chain of hard-point particles interacting through a square--well potential. The evolution of initially localized infinitesimal and finite perturbations is numerically investigated for different density values. All cases belong to the same universality class which can be also interpreted as a Levy walk of the energy with scaling exponent 3/5. The zero-pressure limit is nevertheless exceptional in that normal diffusion is found in tangent space and yet anomalous diffusion with a different rate for perturbations of finite amplitude. The different behaviour of the two classes of perturbations is traced back to the "stable chaos" type of dynamics exhibited by this model. Finally, the effect of an additional internal degree of freedom is investigated, finding that it does not modify the overall scenarioComment: 16 pages, 15 figure