Shielded ionisation discharge (SID) probe for spatiotemporal profiling of pulsed molecular beam.

Intense pulsed supersonic molecular beams are used in many applications such as tokamak fueling, edge plasma diagnostics, ion beam profile monitors, laser cluster experiments, chemical kinetics, etc. Measurement of absolute density is required to optimize beam sources used in these experiments. Absolute density measurement of a continuous molecular beam is challenging due to its small size and rarefied flow, which makes it even more difficult for a pulsed molecular beam due to its transient nature.

Spatial mapping of low pressure cluster jets using Rayleigh scattering.

In this work, we report evolution of atomic clusters in a highly under-expanded supersonic jet of Argon. A high resolution and sensitive Rayleigh scattering based experimental set-up is designed to overcome the limitations encountered in conventional set-ups. Further, the measurement range could be extended from a few nozzle diameters to 50 nozzle diameters.

Exploring the superhydrophilicity of nanosecond laser textured silicon: a Raman analysis.

We present Raman analysis of nanosecond laser textured silicon. The samples have also been characterized by field emission scanning electron microscopy (FESEM) and x ray diffraction. Contact angles (CAs) are measured to trace the hydrophilic nature.

Observation of ion acceleration in nanosecond laser generated plasma on a nickel thin film under rear ablation geometry.

In this article we report acceleration observed for the ions produced in a 50-nm-thick nickel film coated on a quartz substrate, under nanosecond laser ablation, in the rear ablation geometry. A detailed study with varying background pressure and laser energy is done. Spectroscopic study including spectroscopic time of flight (STOF) measurements of ionic and other neutral transitions from the plasma has been undertaken.

Design and development of detector signal conditioning electronics for SST-1 Thomson scattering system.

An IR enhanced thermoelectrically cooled Si-avalanche photodiode (Si-APD) module is used for detection of scattered photons from plasma electrons. Present design of signal conditioning electronics for the APD has fast (50 MHz) and slow (500 kHz) channels to measure scattered and plasma background light, respectively. We report design analysis for different stages and their performance.

Design of multipulse Thomson scattering diagnostic for SST-1 tokamak.

A multipulse Nd:YAG (Yttrium aluminum garnet) Thomson scattering (TS) system is designed and developed for measuring electron temperature (T(e)) and density (n(e)) profiles of SST-1 tokamak. The system operates at vertical, divertor, and horizontal (midplane) regions of plasma and measures the electron temperature of 20 eV to 1.5 keV and density of 10(18)-10(19) m(-3).