Sangeeta Punjabi - Academia.edu (original) (raw)

Papers by Sangeeta Punjabi

Research paper thumbnail of Computational Fluid Dynamics (CFD) Simulations and Experimental Measurements in an Inductively-Coupled Plasma Generator Operating at Atmospheric Pressure: Performance Analysis and Parametric Study

Processes, Mar 4, 2019

In this article, electrical characteristics of a high-power inductively-coupled plasma (ICP) torc... more In this article, electrical characteristics of a high-power inductively-coupled plasma (ICP) torch operating at 3 MHz are determined by direct measurement of radio-frequency (RF) current and voltage together with energy balance in the system. The variation of impedance with two parameters, namely the input power and the sheath gas flow rate for a 50 kW ICP is studied. The ICP torch system is operated at near atmospheric pressure with argon as plasma gas. It is observed that the plasma resistance increases with an increase in the RF-power. Further, the torch inductance decreases with an increase in the RF-power. In addition, plasma resistance and torch inductance decrease with an increase in the sheath gas flow rate. The oscillator efficiency of the ICP system ranges from 40% to 80% with the variation of the Direct current (DC) powers. ICP has also been numerically simulated using Computational Fluid Dynamics (CFD) to predict the impedance profile. A good agreement was found between the CFD predictions and the impedance experimental data published in the literature.

Research paper thumbnail of A diagnostic to measure neutral-atom density in fusion-research plasmas

Review of Scientific Instruments

A femtosecond two-photon-absorption laser-induced-fluorescence (TALIF) diagnostic was designed, i... more A femtosecond two-photon-absorption laser-induced-fluorescence (TALIF) diagnostic was designed, installed, and operated on the Princeton-Field-Reversed Configuration-2 device to provide non-invasive measurements of the time and spatially resolved neutral-atom densities in its plasmas. Calibration of the Ho density was accomplished by comparison with Kr TALIF. Measurements on plasmas formed of either H2 or Kr fill gases allowed examination of nominally long and short ionization mean-free-path regimes. With multi-kW plasma heating and H2 fill gas, a spatially uniform Ho density of order 1017 m−3 was measured with better than ±2 mm and 10 µs resolution. Under similar plasma conditions but with Kr fill gas, a 3-fold decrease in the in-plasma Kr density was observed.

Research paper thumbnail of Analysis and Mitigation of Pulse-Pile-Up Artifacts in Plasma Pulse-Height X-ray Spectra

Plasma

Pulse pile-up in pulse-height energy analyzers increases when the incident rate of pulses increas... more Pulse pile-up in pulse-height energy analyzers increases when the incident rate of pulses increases relative to the inverse of the dead time per pulse of the detection system. Changes in the observed energy distributions with incident rate and detector-electronics-formed pulse shape then occur. We focus on weak high energy tails in X-ray spectra, important for measurements on partially ionized, warm (50–500 eV average electron energy), pure hydrogen plasma. A first-principles two-photon pulse-pile-up model is derived specific to trapezoidal-shaped pulses; quantitative agreement is found between the measurements and the model’s predictions. The model is then used to diagnose pulse-pile-up tail artifacts and mitigate them in relatively low count-rate spectra.

Research paper thumbnail of Evaluation of a collisional radiative model for electron temperature determination in hydrogen plasma

Review of Scientific Instruments

A collisional-radiative (CR) model that extracts the electron temperature, T e, of hydrogen plasm... more A collisional-radiative (CR) model that extracts the electron temperature, T e, of hydrogen plasmas from Balmer-line-ratio measurements is examined for the plasma electron density, n e, and T e ranges of 1010–1015 cm−3 and 5–500 eV, respectively. The CR code, developed and implemented in Python, has a forward component that computes the densities of excited states up to n = 15 as functions of T e, n e, and the molecular-to-atomic neutral ratio r(H2/H). The backward component provides n e and r(H2/H) as functions of the Balmer ratios to predict the T e. The model assumes Maxwellian electrons. The density profiles of the electrons and of the molecular and atomic hydrogen neutrals are shown to be of great importance, as is the accuracy of the line-ratio measurement method.

Research paper thumbnail of Spectroscopic Line Ratio Determination of Electron Density, Electron Temperature, and H$_2$ Dissociation Fraction in PFRC-2 Pulsed Hydrogen Plasmas

Bulletin of the American Physical Society, 2019

Research paper thumbnail of High performance discharges in the Lithium Tokamak eXperiment with liquid lithium wallsa)

Research paper thumbnail of A comprehensive study of different gases in inductively coupled plasma torch operating at one atmosphere

Physics of Plasmas, 2012

ABSTRACT A numerical study is done to understand the possible operating regimes of RF-ICP torch (... more ABSTRACT A numerical study is done to understand the possible operating regimes of RF-ICP torch (3 MHz, 50 kW) using different gases for plasma formation at atmospheric pressure. A two dimensional numerical simulation of RF-ICP torch using argon, nitrogen, oxygen, and air as plasma gas has been investigated using computational fluid dynamic (CFD) software FLUENT V C . The operating parameters varied here are central gas flow, sheath gas flow, RF-power dissipated in plasma, and plasma gas. The temperature contours, flow field, axial, and radial velocity profiles were investigated under different operating conditions. The plasma resistance, inductance of the torch, and the heat distribution for various plasma gases have also been investigated. The plasma impedance of ICP torch varies with different operating parameters and plays an important role for RF oscillator design and power coupling. These studies will be useful to decide the design criteria for ICP torches required for different material processing applications. V C 2012 American Institute of Physics. [doi:10.1063/1.3676598]

Research paper thumbnail of Comparative study of laminar and turbulent flow model with different operating parameters for radio frequency-inductively coupled plasma torch working at 3  MHz frequency at atmospheric pressure

Physics of Plasmas, 2014

ABSTRACT This paper provides 2D comparative study of results obtained using laminar and turbulent... more ABSTRACT This paper provides 2D comparative study of results obtained using laminar and turbulent flow model for RF (radio frequency) Inductively Coupled Plasma (ICP) torch. The study was done for the RF-ICP torch operating at 50kW DC power and 3MHz frequency located at BARC. The numerical modeling for this RF-ICP torch is done using ANSYS software with the developed User A comparative study is done between laminar and turbulent flow model to investigate how temperature and flow fields change when using different operating conditions such as (a) swirl and no swirl velocity for sheath gas flow rate, (b) variation in sheath gas flow rate, and (c) variation in plasma gas flow rate. These studies will be useful for different material processing applications.

Research paper thumbnail of The effect of various coil parameters on ICP torch simulation

Journal of Physics: Conference Series, 2010

... The effect of various coil parameters on ICP torch simulation Sangeeta B Punjabi1*, TK Das2, ... more ... The effect of various coil parameters on ICP torch simulation Sangeeta B Punjabi1*, TK Das2, NK Joshi2, HA Mangalvedekar1, BK Lande1 and AK Das2. 1Electrical Engg. ... 2Laser and Plasma Technology Division, BARC, Mumbai 400085, India. *Email: p.sangeeta@gmail.com ...

Research paper thumbnail of State-space modeling of the radio frequency inductively-coupled plasma generator

Journal of Physics: Conference Series, 2010

Computational fluid dynamics models of RF-ICP are useful in understanding the basic transport phe... more Computational fluid dynamics models of RF-ICP are useful in understanding the basic transport phenomenon in an ICP torch under a wide variety of operating conditions. However, these models lack the ability to evaluate the effects of the plasma condition on the RF generator. In this paper, simulation of an induction plasma generator has been done using state space modelling by considering inductively coupled plasma as a part of RF network .The time dependent response of the RF-ICP generator circuit to given input excitation has been computed by extracting the circuit's state-space variables and their constraint matrices. MATLAB 7.1 software has been used to solve the state equations. The values of RF coil current, frequency and plasma power has been measured experimentally also at different plate bias voltage. The simulated model is able to predict RF coil current, frequency, plasma power, overall efficiency of the generator. The simulated and measured values are in agreement with each other. This model can prove useful as a design tool for the Induction plasma generator.

Research paper thumbnail of The effect of swirl velocity on ICP torch simulation

Journal of Physics: Conference Series, 2010

In this paper numerical simulation is performed to investigate the effects of swirl velocity on t... more In this paper numerical simulation is performed to investigate the effects of swirl velocity on the characteristics of argon discharges in 2D axi-symmetric inductively coupled plasma (ICP) torch working at atmospheric pressure. Simulations were carried out using an indigenously developed CFD code for the standard RF-ICP torch geometry under the assumption of local thermodynamic assumption (LTE), steady and laminar flow. The argon plasma is simulated at oscillator frequency of 3.0 MHz with coil current 150 Amp. Study has been done for different swirl velocities of plasma and sheath gas. In this paper, we consider the swirl of sheath and plasma gas and reverse swirl. In reverse swirl, at the inlet, swirl is given to plasma gas in one direction and sheath gas in the opposite directions. The swirl effect has been adjudged from thermal energy transport point of view. It has been found that swirl of sheath gas increases the wall heat loss and decreases the axial temperature towards the outlet of the torch. The increased heat transfer rate along the periphery of plasma core, due to swirl velocity, increases the stability of plasma core.

Research paper thumbnail of Solasodine glycoalkaloids: a novel topical therapy for basal cell carcinoma. A double-blind, randomized, placebo-controlled, parallel group, multicenter study

International journal of dermatology, 2008

To assess the safety and efficacy of a 0.005% mixture of solasodine glycosides (Zycure) in the tr... more To assess the safety and efficacy of a 0.005% mixture of solasodine glycosides (Zycure) in the treatment of basal cell carcinoma. Design Double-blind, randomized, and vehicle-controlled, parallel group study. Ten centers in the United Kingdom. Participants Male, n = 50; female, n = 44; age range, 32-95 years (Table 1). Ninety-four patients were randomized on a 2 : 1 ratio (n = 62, Zycure; n = 32, vehicle). Histologically confirmed lesions were treated double blinded, twice daily under occlusion with Zycure or vehicle for 8 weeks. Patients were reviewed fortnightly for adverse effects and overall response. Successfully treated patients were followed up at six-month intervals for a year. The primary efficacy endpoint was histologically confirmed clearance of the basal cell carcinoma (2-mm punch biopsy) at the end of 8-week treatment. Efficacy (intention-to-treat population) at 8 weeks was 66% (41/62) in the Zycure group, compared to 25% (8/32) in the vehicle group (P < 0.001; Cochr...

Research paper thumbnail of A comprehensive study of different gases in inductively coupled plasma torch operating at one atmosphere

Research paper thumbnail of Flow and temperature patterns in an inductively coupled plasma reactor: Experimental measurements and CFD simulations

AIChE Journal, 2014

ABSTRACT Measurements of temperature patterns in an Inductively Coupled Plasma (ICP) have been ca... more ABSTRACT Measurements of temperature patterns in an Inductively Coupled Plasma (ICP) have been carried out experimentally. Plasma torch was operated at different RF powers in the range of 3kW to 14 kW at near atmospheric pressure and over a wide range of sheath gas flow rate (3 - 25 lpm). Measurements were made at five different axial positions in ICP torch. The chordal intensities were converted into a radial intensity profile by Abel Inversion technique. Typical radial temperature profile shows an off-axis temperature peak which shifts towards the wall as the power increases. Temperatures in the range of 6000 K to 14000 K were recorded by this method. The temperature profiles in the plasma reactor were simulated using Computational Fluid Dynamics (CFD). A good agreement was found between the CFDpredictions of the flow and temperature pattern with those published in the literature as well as the temperature profiles measured in the present work. © 2014 American Institute of Chemical Engineers AIChE J, 2014

Research paper thumbnail of The effect of various coil parameters on ICP torch simulation

Journal of Physics: Conference Series, 2010

... The effect of various coil parameters on ICP torch simulation Sangeeta B Punjabi1*, TK Das2, ... more ... The effect of various coil parameters on ICP torch simulation Sangeeta B Punjabi1*, TK Das2, NK Joshi2, HA Mangalvedekar1, BK Lande1 and AK Das2. 1Electrical Engg. ... 2Laser and Plasma Technology Division, BARC, Mumbai 400085, India. *Email: p.sangeeta@gmail.com ...

Research paper thumbnail of State-space modeling of the radio frequency inductively-coupled plasma generator

Journal of Physics: Conference Series, 2010

Computational fluid dynamics models of RF-ICP are useful in understanding the basic transport phe... more Computational fluid dynamics models of RF-ICP are useful in understanding the basic transport phenomenon in an ICP torch under a wide variety of operating conditions. However, these models lack the ability to evaluate the effects of the plasma condition on ...

Research paper thumbnail of The effect of swirl velocity on ICP torch simulation

Journal of Physics: Conference Series, 2010

In this paper numerical simulation is performed to investigate the effects of swirl velocity on t... more In this paper numerical simulation is performed to investigate the effects of swirl velocity on the characteristics of argon discharges in 2D axi-symmetric inductively coupled plasma (ICP) torch working at atmospheric pressure. Simulations were carried out using an indigenously developed CFD code for the standard RF-ICP torch geometry under the assumption of local thermodynamic assumption (LTE), steady and laminar flow.

Research paper thumbnail of Comparative study of laminar and turbulent flow model with different operating parameters for radio frequency-inductively coupled plasma torch working at 3 MHz frequency at atmospheric pressure

Physics of Plasmas, 2014

This paper provides 2D comparative study of results obtained using laminar and turbulent flow mod... more This paper provides 2D comparative study of results obtained using laminar and turbulent flow model for RF (radio frequency) Inductively Coupled Plasma (ICP) torch. The study was done for the RF-ICP torch operating at 50 kW DC power and 3 MHz frequency located at BARC. The numerical modeling for this RF-ICP torch is done using ANSYS software with the developed User Defined Function. A comparative study is done between laminar and turbulent flow model to investigate how temperature and flow fields change when using different operating conditions such as (a) swirl and no swirl velocity for sheath gas flow rate, (b) variation in sheath gas flow rate, and (c) variation in plasma gas flow rate. These studies will be useful for different material processing applications. V C 2014 AIP Publishing LLC. [http://dx.

Research paper thumbnail of Computational Fluid Dynamics (CFD) Simulations and Experimental Measurements in an Inductively-Coupled Plasma Generator Operating at Atmospheric Pressure: Performance Analysis and Parametric Study

Processes, Mar 4, 2019

In this article, electrical characteristics of a high-power inductively-coupled plasma (ICP) torc... more In this article, electrical characteristics of a high-power inductively-coupled plasma (ICP) torch operating at 3 MHz are determined by direct measurement of radio-frequency (RF) current and voltage together with energy balance in the system. The variation of impedance with two parameters, namely the input power and the sheath gas flow rate for a 50 kW ICP is studied. The ICP torch system is operated at near atmospheric pressure with argon as plasma gas. It is observed that the plasma resistance increases with an increase in the RF-power. Further, the torch inductance decreases with an increase in the RF-power. In addition, plasma resistance and torch inductance decrease with an increase in the sheath gas flow rate. The oscillator efficiency of the ICP system ranges from 40% to 80% with the variation of the Direct current (DC) powers. ICP has also been numerically simulated using Computational Fluid Dynamics (CFD) to predict the impedance profile. A good agreement was found between the CFD predictions and the impedance experimental data published in the literature.

Research paper thumbnail of A diagnostic to measure neutral-atom density in fusion-research plasmas

Review of Scientific Instruments

A femtosecond two-photon-absorption laser-induced-fluorescence (TALIF) diagnostic was designed, i... more A femtosecond two-photon-absorption laser-induced-fluorescence (TALIF) diagnostic was designed, installed, and operated on the Princeton-Field-Reversed Configuration-2 device to provide non-invasive measurements of the time and spatially resolved neutral-atom densities in its plasmas. Calibration of the Ho density was accomplished by comparison with Kr TALIF. Measurements on plasmas formed of either H2 or Kr fill gases allowed examination of nominally long and short ionization mean-free-path regimes. With multi-kW plasma heating and H2 fill gas, a spatially uniform Ho density of order 1017 m−3 was measured with better than ±2 mm and 10 µs resolution. Under similar plasma conditions but with Kr fill gas, a 3-fold decrease in the in-plasma Kr density was observed.

Research paper thumbnail of Analysis and Mitigation of Pulse-Pile-Up Artifacts in Plasma Pulse-Height X-ray Spectra

Plasma

Pulse pile-up in pulse-height energy analyzers increases when the incident rate of pulses increas... more Pulse pile-up in pulse-height energy analyzers increases when the incident rate of pulses increases relative to the inverse of the dead time per pulse of the detection system. Changes in the observed energy distributions with incident rate and detector-electronics-formed pulse shape then occur. We focus on weak high energy tails in X-ray spectra, important for measurements on partially ionized, warm (50–500 eV average electron energy), pure hydrogen plasma. A first-principles two-photon pulse-pile-up model is derived specific to trapezoidal-shaped pulses; quantitative agreement is found between the measurements and the model’s predictions. The model is then used to diagnose pulse-pile-up tail artifacts and mitigate them in relatively low count-rate spectra.

Research paper thumbnail of Evaluation of a collisional radiative model for electron temperature determination in hydrogen plasma

Review of Scientific Instruments

A collisional-radiative (CR) model that extracts the electron temperature, T e, of hydrogen plasm... more A collisional-radiative (CR) model that extracts the electron temperature, T e, of hydrogen plasmas from Balmer-line-ratio measurements is examined for the plasma electron density, n e, and T e ranges of 1010–1015 cm−3 and 5–500 eV, respectively. The CR code, developed and implemented in Python, has a forward component that computes the densities of excited states up to n = 15 as functions of T e, n e, and the molecular-to-atomic neutral ratio r(H2/H). The backward component provides n e and r(H2/H) as functions of the Balmer ratios to predict the T e. The model assumes Maxwellian electrons. The density profiles of the electrons and of the molecular and atomic hydrogen neutrals are shown to be of great importance, as is the accuracy of the line-ratio measurement method.

Research paper thumbnail of Spectroscopic Line Ratio Determination of Electron Density, Electron Temperature, and H$_2$ Dissociation Fraction in PFRC-2 Pulsed Hydrogen Plasmas

Bulletin of the American Physical Society, 2019

Research paper thumbnail of High performance discharges in the Lithium Tokamak eXperiment with liquid lithium wallsa)

Research paper thumbnail of A comprehensive study of different gases in inductively coupled plasma torch operating at one atmosphere

Physics of Plasmas, 2012

ABSTRACT A numerical study is done to understand the possible operating regimes of RF-ICP torch (... more ABSTRACT A numerical study is done to understand the possible operating regimes of RF-ICP torch (3 MHz, 50 kW) using different gases for plasma formation at atmospheric pressure. A two dimensional numerical simulation of RF-ICP torch using argon, nitrogen, oxygen, and air as plasma gas has been investigated using computational fluid dynamic (CFD) software FLUENT V C . The operating parameters varied here are central gas flow, sheath gas flow, RF-power dissipated in plasma, and plasma gas. The temperature contours, flow field, axial, and radial velocity profiles were investigated under different operating conditions. The plasma resistance, inductance of the torch, and the heat distribution for various plasma gases have also been investigated. The plasma impedance of ICP torch varies with different operating parameters and plays an important role for RF oscillator design and power coupling. These studies will be useful to decide the design criteria for ICP torches required for different material processing applications. V C 2012 American Institute of Physics. [doi:10.1063/1.3676598]

Research paper thumbnail of Comparative study of laminar and turbulent flow model with different operating parameters for radio frequency-inductively coupled plasma torch working at 3  MHz frequency at atmospheric pressure

Physics of Plasmas, 2014

ABSTRACT This paper provides 2D comparative study of results obtained using laminar and turbulent... more ABSTRACT This paper provides 2D comparative study of results obtained using laminar and turbulent flow model for RF (radio frequency) Inductively Coupled Plasma (ICP) torch. The study was done for the RF-ICP torch operating at 50kW DC power and 3MHz frequency located at BARC. The numerical modeling for this RF-ICP torch is done using ANSYS software with the developed User A comparative study is done between laminar and turbulent flow model to investigate how temperature and flow fields change when using different operating conditions such as (a) swirl and no swirl velocity for sheath gas flow rate, (b) variation in sheath gas flow rate, and (c) variation in plasma gas flow rate. These studies will be useful for different material processing applications.

Research paper thumbnail of The effect of various coil parameters on ICP torch simulation

Journal of Physics: Conference Series, 2010

... The effect of various coil parameters on ICP torch simulation Sangeeta B Punjabi1*, TK Das2, ... more ... The effect of various coil parameters on ICP torch simulation Sangeeta B Punjabi1*, TK Das2, NK Joshi2, HA Mangalvedekar1, BK Lande1 and AK Das2. 1Electrical Engg. ... 2Laser and Plasma Technology Division, BARC, Mumbai 400085, India. *Email: p.sangeeta@gmail.com ...

Research paper thumbnail of State-space modeling of the radio frequency inductively-coupled plasma generator

Journal of Physics: Conference Series, 2010

Computational fluid dynamics models of RF-ICP are useful in understanding the basic transport phe... more Computational fluid dynamics models of RF-ICP are useful in understanding the basic transport phenomenon in an ICP torch under a wide variety of operating conditions. However, these models lack the ability to evaluate the effects of the plasma condition on the RF generator. In this paper, simulation of an induction plasma generator has been done using state space modelling by considering inductively coupled plasma as a part of RF network .The time dependent response of the RF-ICP generator circuit to given input excitation has been computed by extracting the circuit's state-space variables and their constraint matrices. MATLAB 7.1 software has been used to solve the state equations. The values of RF coil current, frequency and plasma power has been measured experimentally also at different plate bias voltage. The simulated model is able to predict RF coil current, frequency, plasma power, overall efficiency of the generator. The simulated and measured values are in agreement with each other. This model can prove useful as a design tool for the Induction plasma generator.

Research paper thumbnail of The effect of swirl velocity on ICP torch simulation

Journal of Physics: Conference Series, 2010

In this paper numerical simulation is performed to investigate the effects of swirl velocity on t... more In this paper numerical simulation is performed to investigate the effects of swirl velocity on the characteristics of argon discharges in 2D axi-symmetric inductively coupled plasma (ICP) torch working at atmospheric pressure. Simulations were carried out using an indigenously developed CFD code for the standard RF-ICP torch geometry under the assumption of local thermodynamic assumption (LTE), steady and laminar flow. The argon plasma is simulated at oscillator frequency of 3.0 MHz with coil current 150 Amp. Study has been done for different swirl velocities of plasma and sheath gas. In this paper, we consider the swirl of sheath and plasma gas and reverse swirl. In reverse swirl, at the inlet, swirl is given to plasma gas in one direction and sheath gas in the opposite directions. The swirl effect has been adjudged from thermal energy transport point of view. It has been found that swirl of sheath gas increases the wall heat loss and decreases the axial temperature towards the outlet of the torch. The increased heat transfer rate along the periphery of plasma core, due to swirl velocity, increases the stability of plasma core.

Research paper thumbnail of Solasodine glycoalkaloids: a novel topical therapy for basal cell carcinoma. A double-blind, randomized, placebo-controlled, parallel group, multicenter study

International journal of dermatology, 2008

To assess the safety and efficacy of a 0.005% mixture of solasodine glycosides (Zycure) in the tr... more To assess the safety and efficacy of a 0.005% mixture of solasodine glycosides (Zycure) in the treatment of basal cell carcinoma. Design Double-blind, randomized, and vehicle-controlled, parallel group study. Ten centers in the United Kingdom. Participants Male, n = 50; female, n = 44; age range, 32-95 years (Table 1). Ninety-four patients were randomized on a 2 : 1 ratio (n = 62, Zycure; n = 32, vehicle). Histologically confirmed lesions were treated double blinded, twice daily under occlusion with Zycure or vehicle for 8 weeks. Patients were reviewed fortnightly for adverse effects and overall response. Successfully treated patients were followed up at six-month intervals for a year. The primary efficacy endpoint was histologically confirmed clearance of the basal cell carcinoma (2-mm punch biopsy) at the end of 8-week treatment. Efficacy (intention-to-treat population) at 8 weeks was 66% (41/62) in the Zycure group, compared to 25% (8/32) in the vehicle group (P < 0.001; Cochr...

Research paper thumbnail of A comprehensive study of different gases in inductively coupled plasma torch operating at one atmosphere

Research paper thumbnail of Flow and temperature patterns in an inductively coupled plasma reactor: Experimental measurements and CFD simulations

AIChE Journal, 2014

ABSTRACT Measurements of temperature patterns in an Inductively Coupled Plasma (ICP) have been ca... more ABSTRACT Measurements of temperature patterns in an Inductively Coupled Plasma (ICP) have been carried out experimentally. Plasma torch was operated at different RF powers in the range of 3kW to 14 kW at near atmospheric pressure and over a wide range of sheath gas flow rate (3 - 25 lpm). Measurements were made at five different axial positions in ICP torch. The chordal intensities were converted into a radial intensity profile by Abel Inversion technique. Typical radial temperature profile shows an off-axis temperature peak which shifts towards the wall as the power increases. Temperatures in the range of 6000 K to 14000 K were recorded by this method. The temperature profiles in the plasma reactor were simulated using Computational Fluid Dynamics (CFD). A good agreement was found between the CFDpredictions of the flow and temperature pattern with those published in the literature as well as the temperature profiles measured in the present work. © 2014 American Institute of Chemical Engineers AIChE J, 2014

Research paper thumbnail of The effect of various coil parameters on ICP torch simulation

Journal of Physics: Conference Series, 2010

... The effect of various coil parameters on ICP torch simulation Sangeeta B Punjabi1*, TK Das2, ... more ... The effect of various coil parameters on ICP torch simulation Sangeeta B Punjabi1*, TK Das2, NK Joshi2, HA Mangalvedekar1, BK Lande1 and AK Das2. 1Electrical Engg. ... 2Laser and Plasma Technology Division, BARC, Mumbai 400085, India. *Email: p.sangeeta@gmail.com ...

Research paper thumbnail of State-space modeling of the radio frequency inductively-coupled plasma generator

Journal of Physics: Conference Series, 2010

Computational fluid dynamics models of RF-ICP are useful in understanding the basic transport phe... more Computational fluid dynamics models of RF-ICP are useful in understanding the basic transport phenomenon in an ICP torch under a wide variety of operating conditions. However, these models lack the ability to evaluate the effects of the plasma condition on ...

Research paper thumbnail of The effect of swirl velocity on ICP torch simulation

Journal of Physics: Conference Series, 2010

In this paper numerical simulation is performed to investigate the effects of swirl velocity on t... more In this paper numerical simulation is performed to investigate the effects of swirl velocity on the characteristics of argon discharges in 2D axi-symmetric inductively coupled plasma (ICP) torch working at atmospheric pressure. Simulations were carried out using an indigenously developed CFD code for the standard RF-ICP torch geometry under the assumption of local thermodynamic assumption (LTE), steady and laminar flow.

Research paper thumbnail of Comparative study of laminar and turbulent flow model with different operating parameters for radio frequency-inductively coupled plasma torch working at 3 MHz frequency at atmospheric pressure

Physics of Plasmas, 2014

This paper provides 2D comparative study of results obtained using laminar and turbulent flow mod... more This paper provides 2D comparative study of results obtained using laminar and turbulent flow model for RF (radio frequency) Inductively Coupled Plasma (ICP) torch. The study was done for the RF-ICP torch operating at 50 kW DC power and 3 MHz frequency located at BARC. The numerical modeling for this RF-ICP torch is done using ANSYS software with the developed User Defined Function. A comparative study is done between laminar and turbulent flow model to investigate how temperature and flow fields change when using different operating conditions such as (a) swirl and no swirl velocity for sheath gas flow rate, (b) variation in sheath gas flow rate, and (c) variation in plasma gas flow rate. These studies will be useful for different material processing applications. V C 2014 AIP Publishing LLC. [http://dx.