The concept and characteristics of the plasma torchWhen the high-frequency electric field is applied to the induction coil, the charged particles produced by partial ionization in the working gas of the plasma for some reason move at high speed under the action of the high frequency alternating electromagnetic field and collide with the gas atom, it ionizes rapidly and massively, forming an avalanche discharge, and the ionized gas forms a closed circular eddy current on the cross-section perpendicular to the magnetic field, a secondary coil equivalent to a transformer is formed in the induction coil and is coupled to the induction coil equivalent to the primary coil. The high temperature generated by this high-frequency induction current heats and ionizes the gas, and forming a torch-like stable plasma torch at the nozzle.
The features are as follows:
(1) the working temperature is high and the working gas is inert, so the atomizing condition is good, which is advantageous to the decomposition of refractory compounds and the excitation of elements, and has a high sensitivity to most elements.
(2) because of the skin effect, the stability is high, the self-absorption phenomenon is small, the linear range of determination is wide.
(3) the ionization of the alkali metal causes less interference due to its high electron density.
(4) ICP is a non-polar discharge, and there is no electrode contamination.
(5) the flow rate of carrier gas in ICP is low, which is favorable for the sample to be fully excited in the central channel, and the sample consumption is also low.
(6) the inert gas is used as the working gas, so the spectral background interference is less.
The above is the concept and characteristics of the plasma torch, I hope to help you.