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Double Plasma Device Laboratory & Helicon Laboratory |
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Overview of Double Plasma Device Laboratory and Helicon Plasma Source LaboratoryDouble Plasma Device Laboratory: Brief introduction and activities The double plasma device (DPD) laboratory’s experimental chamber (120 cm long, 30 cm diameter) is the first one bought by the institute in the early nineties (Fig. 1). Initially it was used to produce plasma by the glow discharge process. Since 2003, using two cylindrical magnetic cages (length 32 cm and diameter 25 cm), filament discharge plasmas (in Argon and in Hydrogen gases) have been produced in two regions in this chamber (Fig. 2). Working pressure is usually kept at ~ 10–4 mbars after evacuating the chamber to ~ 10–6 mbars with a rotary and diffusion pump (1000 l/s). Full lined cusped magnetic cages (1.2 kG/4 kG surface field strength) confine these two regions in which plasmas can be produced separately if needed. These regions, usually separated by a grid and also magnetic filter, as experimental aim demands, are called the source and target regions. As plasma can be produced, confined and studied in both these regions therefore it is called a double plasma device. DPDs allow setting up of various experimental configurations with little effort and difficulty. Such experimental systems are capable of performing studies on diffused plasma characteristics, generation of electron and ion beams, launching of waves, sheath characteristics and a host of other plasma phenomena. With minor changes it can be used to conduct studies on negative ion production and its dynamics. Therefore, DPDs are very versatile and attractive to conduct experiments.
Helicon Plasma Source Laboratory: Brief introduction and activities The Helicon Plasma Source (HeliPS) designed and developed at the Centre of Plasma Physics-Institute for Plasma Research is a versatile device for performing a broad range of research activities. A helicon discharge is known to provide many benefits such as longer operational lifetime, better coupling, stability at low pressures, higher plasma densities (1011 cm-3 and above), low electron temperature (2-10 eV) at comparatively lower operating power and better plasma uniformity over the entire plasma volume. The system in CPP-IPR is operated with a 13.56 MHz radio frequency (RF) power supply. The operating power can be varied upto 3 kWatt. The vacuum chamber of the set-up has two parts; a source chamber and an expansion chamber. The source chamber is made of quartz glass; and has a length of 60 cm and diameter of 10 cm. An expansion chamber of length 40 cm and diameter 30 cm, made of stainless steel, is attached with the source chamber. A right-handed half helical antenna is wrapped around the glass chamber through which power is delivered to the gas injected in the source. There are six electromagnets around the source chamber, which produces an almost uniform axial magnetic field upto 500 G in the source. Previously in HeliPS, experiments are performed in gases such as argon, oxygen, hydrogen, nitrogen and chlorine. Gas mixtures like Ar-N2, Ar-N2-SF6 are also used. External circuit parameters, such as antenna current, plasma resistance, and internal parameters, such as electron density and temperature, have been measured and mode transition studies from capacitive to inductive and finally to helicon mode as well have been carried out. Ion-ion plasma studies for oxygen and hydrogen plasma are done as ion – ion plasmas have considerable importance in plasma R&D. It is widely used in the semiconductor industry for etching and deposition of thin films and have applications in negative ion sources. Nonlinear structures like double layer and ion beam are also observed and studied for specific working conditions. HeliPS can be used for experimental studies on basic helicon plasma properties, nonlinear studies, wave propagation, wave coupling, and plasma instability. Different plasma applications like surface modification with ion implantation (PBII or PIII) may also be explored in future.
Research - IResearch - IIPeople
Publications (Double Plasma Device Laboratory)
Publications (Helicon Plasma Source Laboratory)
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