Defects and Damage Studies Division (DDSD) focuses on studies on defects, defect-impurity interactions in reactor structural materials, supplemented by computations. Ion beam radiation damage studies are carried out using a 1.7 MV tandem accelerator and a 400 keV in-house built linear accelerator either in single or dual ion beam modes of irradiation to study defects and radiation response in materials of relevance for fusion and fission reactors. Defects, in particular open volume defects such as vacancies and their clusters are studied using positron annihilation spectroscopy.
Positron beam based Doppler broadening studies have been used mainly for depth resolved defects studies in irradiated materials. Ion beam based characterization techniques such as high resolution RBS, channeling are being used extensively in addition to ion beam induced luminescence studies. Irradiation creep studies are being planned with proton beam of energy 2-3 MeV and high beam current. Various experimental results related to defects are analyzed using detailed computations with a variety of simulation and ab-initio codes. High speed cluster computers at IGCAR are being extensively utilized for computation of materials properties.
Achievements
High-temperature radiation damage studies of Reduced Activation Ferritic/Martensitic (RAFM) steel at fusion relevant He/dpa ratio using positron beam based Doppler broadening spectroscopy
The behavior of the fission gas helium inside thorium oxide fuel was studied by irradiating thorium oxide.
Irradiation effects and defect studies of High Entropy alloys.
Synthesis & DFT studies of the effect of Zr additions in Al containing Oxide Dispersion Strengthened Steels (ODS) alloys and effect of irradiation.
Computation of structural and thermal properties of nuclear fuel materials using ab-initio methods.
Developed independent code for modeling the structural stability and waste storage capacity of iron phosphate glasses
Modeling the thermal and anharmonic properties of 2D materials like graphene.
Studies on the effect of doping on the stability and waste storage capacity of iron phosphate glasses for nuclear waste management applications.
Bulk and local structural & magnetic studies of multiferroic materials and Co& Fe based Heusler compounds.
Grain boundary electron emission mechanism in N+ ion implanted Ultra nano-crystalline cubic diamond (UNCD) & Enhanced Electron Field Emission in Au implanted UNCD.
Non Equilibrium Green function’s study of spin transfer torque in non-collinear magnetic tunnel junctions exhibiting quasiparticle bands.
First principles study of Uranium intermetallic U2Ti.
Interatomic Potential Development & MD Simulations in Y-Ti-O Systems.
Effects of Si ion-irradiations on Ag nanoparticles.
Expertise
Developed in-house an advanced low energy positron beam based spectrometer for deducing Doppler broadening of annihilated photons for depth resolved defects studies in irradiated samples
Development of dual ion beam irradiation facilities, unique in India, using Accelerators to emulate better the irradiation conditions of fission and fusion candidate materials for purposes such as material screening and evaluation of basic mechanisms or model calibration.
Indigenous development of 400 keV accelerator
Development of High Resolution RBS spectrometer
Development of in-situ Iono luminescence system
Designed and developed a fibre optically linked distributed control electronics and instrumentation to facilitate control and monitoring of the UHV beam line and the 400kV accelerator. Some of the important features of the control system include fibre optic communication for high voltage isolation, fast data rate(1.2 MBaud) and no transient pick up, modular design, high resolution, high update rate upto 32k channels/sec, rugged and reliable operation through fault-tolerant and self-correcting software and built-in diagnostics.
Development of photonic sources as bipartite quantum systems with tunable entanglement content.
Reconstruction of two-photon entangled states through tomographic methods.
Carried out studies involving single-photon and two-photon interferometers.
Development of novel schemes for improving the quality of entanglement, through the process of distillation and their experimental verification
Generation of light beams having arbitrary superpositions of spin and orbital angular momenta.
Development of novel polarization based gadgets for complex beam shaping and for the generation of structured light beams through tailoring of their polarization, phase and amplitude.
Development of discrete-time quantum walks have been implemented using the spin and orbital angular momentum of photons.
Development of theoretical tools for exploiting Pancharatnam-Berry Optical Elements (PBOEs) for realizing arbitrary beams shaping.
Development of theoretical tools for exploiting discrete Winger function formalizing for characterizing entanglement in single qubit as well as multi-partite quantum systems.
Studies of accoustic phonon oscillations in semi-conductors using time-resolved spectroscopy. In pure GaAs, the lineshape of these oscillations is shown to have a pronounced asymmetry close to the bandgap
Infrastructure
Irradiation and ion implantation Facilities:
1.7 Mev Accelerator.
400 KeV Accelerator
150 kV Accelerator
XRD
Microscopic Characterisation :SEM & TEM
RBS (Rutherford Backscattering Spectrometry), Ion Channeling (depth profiling, lattice locations of impurities)
