R. D. Tarey

R. D. Tarey
Indian Institute of Technology Delhi | IIT Delhi · Department of Physics

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51
Publications
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532
Citations

Publications

Publications (51)
Article
Hydrogen plasma characterization was carried out in a large volume (dia∼ 1.0 m, h∼ 1.0 m) plasma chamber to evaluate the efficacy of production of uniform, large-area H ⁻ beam for fusion applications. Up to seven Compact ECR Plasma Sources (CEPS; Indian Patent #301583, Patentee: IIT Delhi) can be mounted on the top dome of the chamber (one in centr...
Article
Full-text available
In recent years, there have been intense research and development work on Electron Cyclotron Resonance (ECR) plasma sources owing to the numerous applications of ECR plasmas in various fields. In view of this, a portable Compact ECR Plasma Source (CEPS) has been successfully designed, developed and patented at Indian Institute of Technology Delhi....
Article
This paper reports parallel plate DC glow discharge plasma experiments showing significant changes in the nature of the anode sheath when the plasma boundary is changed from a large, grounded, conducting boundary (CB; the vacuum vessel) acting as an extended cathode to the one wherein the plasma is encapsulated completely by an insulating boundary...
Article
Argon and hydrogen plasmas were produced by a Compact ECR Plasma Source (CEPS) attached coaxially to a large chamber. This paper presents characterization results of the two plasmas using a newly designed Langmuir Probe. Experiments in argon were conducted to benchmark the plasma parameters and to determine the efficacy of the CEPS for thruster app...
Conference Paper
This paper reports the behavior of anode sheath in a planar dc discharge system brought about by changing the plasma boundary. Although no Negative Differential Resistance (NDR) region was observed in the current-voltage (Id-Vd) characteristics of the discharge in fully open or fully closed cases [1], an NDR region (sudden increase in Id along with...
Conference Paper
Full-text available
In a recent paper [Ganguli et al., Plasma Sources Sci. Technol. 2019 in press https://doi.org/10.1088/1361-6595/ab0969], the thruster capability of a permanent magnet based Compact ECR Plasma Source (CEPS) connected to a small test chamber was explored. Based on the results, it was realized that a standalone CEPS thruster should be feasible. The pr...
Article
The performance of a plasma thruster is assessed for efficient propulsion by analyzing the unique downstream characteristics of plasma produced by a Compact ECR Plasma Source (CEPS). For this, data presented in an earlier publication (Ganguli et al 2016 Plasma Sources Sci. Technol. 25 025026), wherein plasma produced in the CEPS is allowed to flow...
Article
This paper presents a scheme for large volume plasma production using multiple highly portable compact ECR plasma sources (CEPS) (Ganguli et al 2016 Plasma Source Sci. Technol. 25 025026). The large volume plasma system (LVPS) described in the paper is a scalable, cylindrical vessel of diameter ≈1 m, consisting of source and spacer sections with mu...
Article
It is well known that electron cyclotron resonance (ECR) produced plasmas are efficient, high-density plasma sources and have many industrial applications. The concept of a portable compact ECR plasma source (CEPS) would thus become important from an application point of view. This paper gives details of such a CEPS that is both portable and easily...
Article
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The present work discusses an overview of RF power absorption in helicon plasmas. Analysis suggests that the warm electron population is accountable for the argon plasma ionization in helicon plasma. Along with the experiment, there is an observation of a potential structure, identified as a double layer. However, unlike the other helicon double la...
Article
Full-text available
The paper presents investigations of current free double layer (CFDL) that forms in helicon plasmas. In contrast to the other work reporting on the same subject, in the present investigations the double layer (DL) forms in a mirror-like magnetic field topology. The RF compensated Langmuir probe measurements show multiple DLs, which are in connectio...
Article
Full-text available
A combination of three strong current free double layers (CFDLs) characterized by strength (eΔΦ/Te) ~ 10 and widths (Δz/λD) ~ 7.6, 8, and 8.3 has been observed in argon helicon plasma. In contrast to other works report on the same subject, in the present investigations the DLs form in a mirror-like magnetic field topology and present in the plateau...
Conference Paper
Although it is well known that electron cyclotron resonance (ECR) produced plasmas are efficient, high-density sources and have potential applications in industry, a compact ECR plasma source still remains to be developed. This paper discusses the development of a novel, compact ECR plasma source (CEPS) that is both portable and easily mountable on...
Conference Paper
Hysteresis effects in the I-V characteristics of DC glow discharges have been a subject of considerable interest in different system configurations [1-4]. Mostly these effects are observed in the presence of a third (auxiliary anode) electrode and have been attributed to formation of structures at this electrode. Also, nonlinear oscillations observ...
Conference Paper
form is given. There are several applications which require plasma to be produced over large volumes (~ few cubic meters) and where it is desirable to have high radial / axial uniformity and high plasma density. Although electron cyclotron resonance (ECR) plasma sources are efficient and yield high plasma densities1 these do not scale well with the...
Conference Paper
form only given. Hysteresis effects in the I-V characteristics of DC glow discharges have been a subject of considerable interest in different system configurations1-4. Mostly these effects are observed in the presence of a third (auxiliary anode) electrode and have been attributed to formation of structures at this electrode. Also, nonlinear oscil...
Conference Paper
There are several applications which require plasma to be produced over large volumes (~few cubic meters) and where it is desirable to have high radial/axial uniformity and high plasma density. Although electron cyclotron resonance (ECR) plasma sources are efficient and yield high plasma densities, these do not scale well with the volume. This pape...
Article
Full-text available
This paper investigates the formation of double layer (DL) in helicon plasmas. In the experiment, argon plasma production is using the excitation of m = −1 helicon mode with magnetic mirror field with high mirror ratio of ∼1:1.7. We have specifically used the radio frequency compensated Langmuir probe (LP) to measure the relevant plasma parameters...
Article
Full-text available
This paper presents a comprehensive overview of work on the helicon plasmas and also discusses various aspects of RF power deposition in such plasmas. Some of the work presented here is a review of earlier work on theoretical [A. Ganguli et al., Phys. Plasmas 14, 113503 (2007)] and experimental [A. Ganguli et al., Plasma Sources Sci. Technol. 20(1)...
Article
Full-text available
This paper investigates the mechanisms by which the helicon and associated Trivelpiece–Gould waves are absorbed in helicon discharges produced in conducting chamber; the experiments were based on a recent theory of damping and absorption of helicon modes in conducting waveguides (Ganguli et al 2007 Phys. Plasmas 14 113503). In particular, it was al...
Article
We studied the effect of varying the target temperature (by changing the beam power) on the structure and properties of nitrogen ion implanted 304 stainless steel. With a beam power of 0.1 W/ cm2 the target temperature is restricted to 150°C. After a dose of 3. 5x1017N2+/cm2 the microhardness measured at 10g increases by 15%. With a beam power of 1...
Article
Full-text available
A new Langmuir probe structure using externally placed filters that can be tuned in the absence of plasma is proposed. The probe design and tuning procedure take into account especially the change in the probe's environment when plasma is turned on, thereby ensuring that the filters do not become detuned in the presence of plasma. Measurement of th...
Article
Full-text available
Exact results are presented for the first time for the helicon (H) wave and associated Trivelpiece-Gould (TG) wave modes of a cold, uniform, lossy plasma column inside a conducting waveguide. Both Landau and collisional damping are considered. Contrary to expectation, it is found that even in cases of severe damping, the axial propagation constant...
Article
A kinetic theory model for the absorption of high-frequency guided plasma waves is presented for a warm, inhomogeneous, magnetized plasma column loaded inside a waveguide. Electron cyclotron resonance (ECR) absorption and Landau damping terms, derived as the anti-Hermitian part of the susceptibility tensor, are included in the model for a loss-free...
Article
The paper discusses the basic physical mechanisms behind different plasma discharges. An attempt is made to integrate the analysis by considering the salient changes brought about in discharge formation and plasma behaviour, as the frequency of the applied power is raised from dc to microwave frequencies. Following this, discharge systems commonly...
Article
This paper presents results of plasma production in a mirror machine with the microwaves being coupled from a side port, in the ordinary-mode polarization. In this method of coupling, contamination due to the launching antenna is avoided; also, there is very little window degradation since plasma bombardment on the side port is negligible. The coup...
Article
This paper presents results of high-density plasma production experiments carried out using an optimally designed and excited slotted helical antenna. The slotted helical antenna was excited by linearly polarized, right-hand polarized (RHP) and left-hand polarized (LHP) CW microwaves (f = 2.45 GHz) with power up to 2.5 kW. Two different discharges...
Article
Left-polarized (m = −1) microwaves launched in an electron cyclotron resonance discharge are found to be absorbed efficiently, contrary to expectation. Investigation of microwave penetration into the plasma reveals the presence of large-amplitude, long-wavelength waves, along with bursts of short-wavelength waves localized mostly near the peaks of...
Article
The theory of high-frequency guided waves in a plasma-loaded waveguide is presented. The formulation is based on kinetic theory. The theory includes the effects of finite electron/ion temperatures and radial gradients in the plasma density and particle temperatures. The inclusion of gradients into the formalism results in three, coupled, second-ord...
Article
This paper presents a detailed study on plasma production using an optimally designed slotted helical antenna, excited by a conical horn, in a mirror machine. For maximizing plasma production efficiency, the helical antenna is designed so that only its slow-wave mode (SWM) is excited and the fast wave is eliminated completely. The horn also excites...
Article
Quantitative data on the early morphological development of the human retina show that the peripheral region is relatively more mature than the central region. These results have stimulated researchers to compare the development of visual functions in the central and peripheral regions of the visual field. Here, we used preferential looking to eval...
Article
The influence of nitrogen ion implantation on the structure and wear behaviour of unpolished 304 stainless steel has been studied. Glancing angle X -ray diffraction before implantation showed that the specimens contain some bcc and hcp (martensite) phases, whereas after implantation iron nitrides were observed, accompanied by a reduction in the mar...
Article
The stoichiometry of a-SiN, : H films is determined by conventional elastic recoil detection analysis (ERDA) using 90 MeV 58 Ni ions. Hydrogen depth profiling indicated that the non-uniformity in H concentration across the film thickness is about 12%. The present experiment indicated the capability of conventional ERDA for simultaneous multi-elemen...
Article
Nitrogen ion implantation has proved effective in the surface strengthening of metals and alloys. In order to achieve high throughputs industrially, high beam currents must be used. The resulting high target temperature may cause a difference in the structure of implanted material. In this work the effect of varying the target temperature during ni...
Article
Argon plasma exposure has been used to induce surface chemical modification of aluminium thin films, causing a drastic change in etch rate in standard HNO 3 /CH 3 COOH/H 3 PO 4 etchant. The inhibition period was found to increase with power and Ar plasma exposure time. Auger electron and x-ray photoelectron spectroscopies have indicated formation o...
Article
Plasma etching of crystalline and hydrogenated amorphous silicon has been studied in CClF3 gas as a function of pressure and power using a 30 kHz parallel plate plasma-etching system. In contrast to CF4 plasma, etching of amorphous silicon in CClF3 is found to be slower than that of crystalline silicon. The selectivity of crystalline silicon over a...
Article
A systematic study of etching rates in CF 4 plasma of single‐crystal, polycrystalline, and amorphous silicon exposed to hydrogen plasma has been carried out. An order of magnitude reduction in the etch rates after H 2 plasma treatment has been observed in all cases and has been explained on the basis of an overlayer formation. Electron spectroscopy...
Article
We studied the modification of 304 stainless steel following nitrogen ion implantation. We used grazing incidence X-ray diffraction. Nitride formation is enhanced in specimens containing a significant amount of martensite formed by surface finishing. We report for the first time an increase in surface hardness at depths larger than the implantation...
Article
We studied the modification of 304 stainless steel after nitrogen ion implantation. We report for the first time an increase in surface hardness after annealing of implanted specimens. This increase in hardness requires a martensitic content in the specimen. Ion implantation reduces the martensitic content.
Article
A modified method has been developed for the deposition of transparent semiconducting thin films of tin oxide, involving the chemical vapour phase oxidation of tin iodide. These films show sheet resistances greater than 100 Ω/□ and an average optical transmission in the visible range exceeding 80%. The method avoids uncontrolled contamination, resu...

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