Development of Resonance Pulsed Hairpin Probe for Measurement of Plasma Parameters using LabVIEW

Abstract

This project is devoted towards developing a cost-effective option of a plasma diagnostic technique based on microwave sensor for the purpose of real time monitoring of electron density in low temperature plasma by developing such kind of resonance pulsed hairpin probe. This project consists of two parts. One part based on the microwave source which generates the frequency in the range of 2GHz to 18GHz based on the voltage (0-10V) applied to it. Here automation of the microwave source will be done by the LabVIEW software and acquisition will be done by the DAQ Card. The resonance detection circuit comprises of a directional coupler (Model No- CB7-20) and Schottkey Diode positioned between the YIG oscillator and the sensor. This circuit measures the corresponding reflected power in the co-axial line and displays it in the form of voltage amplitude in an oscilloscope. The resonance frequency is obtained by when a sharp fall in the reflected power is clearly observed at the resonance frequency. In another part to provide high voltage pulse input to the hairpin sensor so for that need to design HV PWM circuit and control it by any software (Lab VIEW) this controlling portion can be possible by using National Instrument DAQ system and amplification of signal can be done by using high voltage power operational amplifier circuit (using PA93 IC). So we design a high voltage amplifier circuit for generating high voltage analogue signal of up to ±200 which will be applied to the hairpin sensor of the resonance pulsed hairpin probe. So the project consists of automation part, interfacing part and hardware part. Also interfacing between Tektronix oscilloscope (TDS 3034C) and DAQ card (BNC 6251) is required for analysis of signal. Here the purpose of development of resonance pulsed hairpin probe is to measure electron density and from that other parameters of plasma.