title: Online tuning of impedance matching circuit for long pulse inductively coupled plasma source operation--an alternate approach.
abstract: Impedance matching circuit between radio frequency (RF) generator and the plasma load, placed between them, determines the RF power transfer from RF generator to the plasma load. The impedance of plasma load depends on the plasma parameters through skin depth and plasma conductivity or resistivity. Therefore, for long pulse operation of inductively coupled plasmas, particularly for high power (∼100 kW or more) where plasma load condition may vary due to different reasons (e.g., pressure, power, and thermal), online tuning of impedance matching circuit is necessary through feedback. In fusion grade ion source operation, such online methodology through feedback is not present but offline remote tuning by adjusting the matching circuit capacitors and tuning the driving frequency of the RF generator between the ion source operation pulses is envisaged. The present model is an approach for remote impedance tuning methodology for long pulse operation and corresponding online impedance matching algorithm based on RF coil antenna current measurement or coil antenna calorimetric measurement may be useful in this regard.
authors: ITER-India, Institute for Plasma Research, A-29, GIDC, Sector-25, Gandhinagar, Gujarat 382 025, India.
authors: Dass
authors: D
authors: Sudhir
authors: ITER-India, Institute for Plasma Research, A-29, GIDC, Sector-25, Gandhinagar, Gujarat 382 025, India.
authors: M
authors: M
authors: Bandyopadhyay
authors: Max-Planck-Institut für Plasmaphysik, Boltzmannstrasse 2, 85740 Garching, Germany.
authors: W
authors: W
authors: Kraus
authors: Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382 428, India.
authors: A
authors: A
authors: Gahlaut
authors: Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382 428, India.
authors: G
authors: G
authors: Bansal
authors: ITER-India, Institute for Plasma Research, A-29, GIDC, Sector-25, Gandhinagar, Gujarat 382 025, India.
authors: A
authors: A
authors: Chakraborty