53 / 2017-09-01 15:00:21

The Analysis of Influence Factors of Impedance in Inductively Coupled Plasma

inductively coupled plasma; circuit model; plasma impedance

Inductively coupled plasma (ICP) has become the
most common ion source in analytical instruments. The
characteristics of the plasma impedance, which are key
parameters of the stability and efficiency of analytical
instruments, can be easily influenced by the working
environments. Therefore, there is an urgent need to investigate
the impedance properties of the plasma. In this work, firstly, the
ICP equivalent circuit model was established by combining the
transformer model and the matching network model. Secondly,
the expression of the ICP impedance were obtained by
calculation. Finally, by changing the experimental conditions
during ICP operation, the relationships between the plasma
impedance and carrier gas, the cooling gas and the power were
obtained, respectively. The results show that the impedance value
of the inductively coupled plasma is very low, changing from
0.5Ω to 1.5Ω. In addition, the plasma impedance increases with
the flow rate of the carrier gas, while, the plasma impedance
decreases with the input power increases. And the impedance of
the plasma was not influenced by the flow rate of the cooling gas