The Design And Development Of Fast Langmuir Probe Measuring Instrument

The Langmuir probe measuring instrument is an instrument device mainly used for plasma parameter measurement. Designing and developing a fast type of measuring instrument based on the conventional measuring instrument, can further expand its range of applications, such as the time distribution of pulsed plasma parameters,spatial and temporal distribution of steady-state plasma parameters, the real-time monitoring of plasma parameters, as well as the diagnosis of high temperature plasma parameters, so it has good application value.For rapid of the probe measurement system, consucted a scheme of comprehensive analysis and design of software and hardware platform; for the key technical issues in specific realization, the design analysis and experimental verification has been done. This work provides the technical basis for the commercialization of the fast Langmuir probe measuring instrument. The research work of this paper lies in the following areas:1, According to user needs of plasma parameters measurement, cleared the major technical indicators of the fast Langmuir probe measuring instrument. In the design, the core of hardware platform is ARM9 processor and the FPGA, the entire hardware system circuit has been designed.2, According to the requirement of high speed and high voltage in the probe voltage scanning, designed and developed a fast high voltage sawtooth signal amplifying module, this laid an important foundation for the output without distortion in the parameter measurements for the pulsed plasma.3, Designed and implemented the front-end high-speed I/V conversion, signal conditioning and back-end high-speed data acquisition circuitry and function. This provided a guarantee for obtaining probe current data fast and accurately.4, Realized the control functions of the linear mechanical scanning system, which is matching with the probe measuring instrument. This provided a condition for measuring spatial distribution of plasma parameters, and further improved the automation of the measurement system.5, Designed the isolation of the ARM9 and FPGA to external channel, which enhanced the anti-jamming capability and improved reliability of ARM9 and FPGA.