Abstract

Irradiation and Implantation studies are being regularly carried out at VECC with the room temperature cyclotron. Activities in Materials Science are having two dimensionalities-1) Studies on Nuclear Structural Materials with a view to assessing the damage in the context of applications to Nuclear reactors and 2) Studies on various novel materials like High Temperature and low temperature superconductors, novel oxides, polymers etc. with the purpose of extracting tailor made properties and understanding the basic mechanism in the process. The second aspect will be talked about. Recently, Superconducting Cyclotron with high energy heavy ions and 6.4GHz ECR ion source are being activated for the purpose of different experiments. The ongoing experiments using ECR source and the future plans will be highlighted.

Abstract

Abstract

Studies at the extreme limits of the nuclear chart have gainedmomentum in the last decade with the advent of new experimentalfacilities. The production of new exotic nuclei lead to the discoveryof several exciting new phenomena like for example, neutron skins andhalos in neutron-rich nuclei, and the novel decay mechanism of protonradioactivity in proton rich nuclei around the proton drip line. Ontheoretical grounds, the description of these new phenomena, apartfrom validating existing models in regions far from stability,requires the formulation of new theories. Recent developments in thisarea will be discussed

Abstract

In my talk I will describe some of the cutting edge experiments that aregoing on in my research group. Our focus is the growth of thin films withatomic level control for both basic science and applications.I will focuson the area of Oxide Electronics where we are focused on a number ofimportant problems.The first will be the observation of ferromagnetism in oxides with nomagnetic dopants such as Nb or Ta doped TiO2. In both these cases,magnetic signatures were first seen by the observation of strong Kondoscattering observed in the low temperature resistivities. We confirm thatthe observed resistivity anomalies arise with a strong Kondo contributionwith a small weak localization contribution.. With further optimizationroom temperature ferromagnetism is seen in these materials. I will discussthe various experimental supporting factors besides just SQUID measurementthat give evidence for this ferromagnetism and how we rule out the effectsof artifacts, a common problem with SQUID only measurements. I will touchupon our recent efforts in the formation of Super Hydrogenic Systems, anew class of materials and give one specific example, that of Ce dopedLu2O3. Lastly but not the least I will cover some of our recentexperiments on integrating oxides with futuristic materials such asgraphene.

Abstract

STAR and PHENIX measurements of elliptic flow, in Au+Au collisions at RHIC,revealed an interesting scaling property: elliptic flow, of different particle species at differentcollisions centrality, when scaled by the initial eccentricity and constituent quark numbers ($n_q$)is a singlefunction of $KE_T/n_q$, $KE_T=m_T-m$. Initial eccentricity scaling suggests that elliptic flow is driven by the initial spatial asymmetry. Constituentquark number scaling indicate existence of initial collective partonic state. Elliptic flow is best explained in ahydrodynamic model. In non-zero impact parameter collisions, the reaction zone is spatially asymmetric.Differential pressure gradient convert the spatial asymmetry to momentum asymmetry, resulting in elliptic flow. Inthe Israel-Stewart’s theory of 2nd order dissipative hydrodynamics, we study the universal scaling of ellipticflow in ideal and viscous fluid evolution. Initial eccentricity scaling is only approximate in ideal hydrodynamicsand gets better with viscosity. Ideal or viscous hydrodynamic do not indicate constituent quarks number scaling anduniversal scaling is only approximate,violated by $sim\% or more in ideal or viscous fluid evolution. We also showthat RHIC data on elliptic flowdemand very small QGP viscosity, $eta/s ~0.08$, indicating nearly ideal fluid isproduced in Au+Au collisions