Upgraded space and time resolved visible spectroscopic diagnostic on ADITYA-U tokamak.

Poloidal asymmetries in neutral and impurity ion temperatures and particle and impurity transports have been observed in many tokamaks. To investigate these asymmetries, space-resolved visible spectroscopic diagnostic of the ADTIYA-U tokamak has been upgraded to measure the spatial profile of Hα and impurities spectral line profile, ion temperature, and plasma rotation from both low and high field sides of the plasma, simultaneously with a better spatial resolution. This has been done by developing a linear array of 15 optical fibers as compared to the present linear array of nine fibers having a core diameter of 400 μm and coupling it to the entrance slit of a 1 m long high-resolution spectrometer of the existing diagnostic.

Role of pinch in Argon impurity transport in ohmic discharges of Aditya-U Tokamak.

We present experimental results of the trace argon impurity puffing in the ohmic plasmas of Aditya-U tokamak performed to study the argon transport behaviour. Argon line emissions in visible and Vacuum Ultra Violet (VUV) spectral ranges arising from the plasma edge and core respectively are measured simultaneously. During the experiments, space resolved brightness profile of Ar line emissions at 472.

Isolation of relaxation times under open-circuit conditions: Toward prognosis of nascent short circuits in Li-ion batteries.

Li-ion battery mishaps are primarily attributed to short circuits, which missed early detection. In this study, a method is introduced to address this issue by analyzing the voltage relaxation, after initiating a rest period. The voltage equilibration arising from solid-concentration profile relaxation is expressed by a double-exponential model, whose time constants, τ & τ, capture the initial, rapid exponential contour and the long-term relaxation, respectively.

Impurity toroidal rotation profile measurement using upgraded high-resolution visible spectroscopic diagnostic on ADITYA-U tokamak.

A high-resolution spectroscopic diagnostic for the measurement of spatial profiles of impurity ion toroidal rotation velocities on the ADITYA-U tokamak has been upgraded to cover the complete plasma minor radius. Earlier, the coverage of diagnostics toward the plasma edge was restricted due to the placement of collection optics on the tangential port outside the vacuum vessel. The coverage of the full plasma minor radius, from 0 to 24 cm, has been achieved using the newly designed and developed collection optics that have seven lines of sight to view the tokamak plasma mounted inside a customized re-entrant view port which is installed in the shadow of the limiter inside the vacuum vessel.

Observations of visible argon line emissions and its spatial profile from Aditya-U tokamak plasma.

The spectroscopic studies of medium and high Z impurities have been the subject of interest in fusion research due to their role in mitigating plasma disruption and reducing heat load on the plasma facing components. Line emissions from these impurities provide the rotation velocity and ion temperature measurements along with the understanding of the overall impurity behavior in plasma. In the Aditya-U tokamak, the spatially resolved Ar II line emissions have been observed using a high resolution multi-track spectroscopic diagnostic consisting of a 1 m Czerny-Turner spectrometer coupled with a charge coupled device (CCD) detector using seven lines of sight viewing plasma tangentially along the toroidal direction.

An Efficient and Chemistry Independent Analysis to Quantify Resistive and Capacitive Loss Contributions to Battery Degradation.

Degradation mechanisms leading to deterioration in the battery performance is an inevitable phenomenon. Although there are detailed physics and equivalent circuit based models to predict the losses incurred due to degradation in estimating the health of the battery, they are either incomplete, computationally expensive or both. In this study, we present a very simple and elegant, chemistry independent mathematical analysis, which accurately calculates resistive and capacitive components of cycle-life related losses in a battery system.

Effect of encapsulation on electronic transport properties of nanoscale Cu(111) films.

The stiff compromise between reliability and conductivity of copper interconnects used in sub-nanometer nodes has brought into focus the choice of encapsulation material. While reliability was the primary driver so far, herein, we investigate how electronic conductivity of Cu(111) thin films is influenced by the encapsulation material using density functional theory and Boltzmann transport equation. Atomically thin 2D materials, namely conducting graphene and insulating graphane both retain the conductivity of Cu films whereas partially hydrogenated graphene (HGr) results in reduction of surface density of states and a reduction in Cu film conductivity.

Plasma rotation measurement using UV and visible spectroscopy on Aditya-U tokamak.

A high resolution spectroscopic diagnostic for the measurement of the spatial profile of toroidal rotation velocity (v) and temperature (T) of carbon ions has been developed and implemented on the Aditya-U tokamak. The diagnostic consists of a high resolution 1 m (/8.7) spectrometer having an 1800 grooves/mm grating coupled with a charged couple device.

Design of tangential x-ray crystal spectrometer for Aditya-U tokamak.

A tangential soft x-ray crystal spectrometer has been designed to measure the x-ray spectrum of He-like argon for the Aditya-U tokamak plasma. The system enables to measure electron temperature using the intensity ratio of the resonance line to the satellite line. For this purpose, an x-ray spectral line at 3.

Characterizing breast cancer tissues through the spectral correlation properties of polarized fluorescence.

We study the spectral correlation properties of the polarized fluorescence spectra of normal and cancerous human breast tissues, corresponding to patients belonging to diverse age groups and socioeconomic backgrounds. The emission range in the visible wavelength regime of 500 to 700 nm is analyzed, with the excitation wavelength at 488 nm, where flavin is one of the active fluorophores. The correlation matrices for parallel and perpendicularly polarized fluorescence spectra reveal correlated domains, differing significantly in normal and cancerous tissues.

Time-dependent complexation of glucose-reduced gold nanoparticles with octadecylamine Langmuir monolayers.

We report on the reduction of aqueous chloroaurate ions by glucose to form gold nanoparticles of uniform size. We further demonstrate the complexation of these particles with octadecylamine (ODA) monolayers at the air-water interface. Pressure-area (pi-A) isotherms as a function of time of complexation revealed a significant expansion of the monolayer.