Generation of high-power arbitrary-wave-form modulated inductively coupled plasmas for materials processing

Abstract

An arbitrary-wave-form modulated induction thermal plasma ͑AMITP͒ system was developed using a high-power semiconductor high-frequency power supply. The modulated high-power plasma is a breakthrough technique for controlling the temperature and the radical density in high-density plasmas. The arbitrary-wave-form modulation of the coil current enables more detailed control of the temperature of the high-density plasmas than the pulse-amplitude modulation that has already been developed. The Ar AMITP with intentionally modulated coil current could be generated at a power of 10-15 kW. Results showed that the Ar excitation temperature between the specified excitation levels was changed intentionally according to the modulation control signal.

Nanoparticle synthesis using high-powered pulse-modulated induction thermal plasma

“…The AMITP system can modulate the coil current not only into a rectangular waveform but also into an externally given waveform. It actually provides precise time-domain control of the temperature of thermal plasmas [25].…”

Modulated Induction Thermal Plasmas – Fundamentals and Applications –

“…Development of arbitrary waveform modulated induction thermal plasma 6.1 Concept and electric circuit for AMITP Recently, we have developed a new type of modulated induction thermal plasma system, that is, a system of an arbitrary-waveform modulated induction thermal plasma (AMITP) (27) . This system can modulated the coil current sustaining an induction thermal plasma not only into a rectangular waveform but also into an externally-given waveform in milliseconds.…”

“…19 shows (a) the modulation signal, (b) the inverter output current in root-mean-square value, (c) the radiation intensity of the Ar atomic line at 703 nm, and (d) the Ar excitation temperature, in a triangular-rectangular waveform modulation case (27) . Input power is 10 kW, Fig.…”

“…19 (d) shows the time evolution in the Ar excitation temperature in case of triangular-rectangular waveform modulation (27) . The Ar excitation temperature is also modulated periodically following a triangular-rectangular control signal, changing from 5500 K to 7000 K. These results implies that the Ar excitation temperature in Ar AMITP can be controlled by the modulated coil current in milliseconds (27) .…”

“…Finally, a new type of modulated induction thermal plasmas, i.e. the arbitrary waveform modulated induction thermal plasma (AMITP) is introduced, and the time evolution in Ar excitation temperature in Ar AMITP is described (27) . This system can modulate the amplitude of the coil current to follow a control signal formed in not only a rectangular waveform but also an externallygiven arbitrary waveform.…”