New Measurement Methods of Dust Charge Based on Infrared Extinction Theory

The dust charge is a very important physical quantity and it needs to be measured accurately to understand the physical characteristics of dusty plasma. Through analyzing the simulated charged dust extinction signal, a new method to measure the dust charge quickly and without interference is sought. The result shows that the scattering mechanism in the far infrared band is low in absorption efficiency, it is necessary to increase the power attenuation by multiplying the light path to realize the measurement of dust charge, the upper limit of allowable particle size is 1 μ m. Resonance absorption mechanism in the middle infrared band, however, increases its absorption efficiency by 4 orders of magnitude, which allows the dust charge measurement with the spectral analysis method according to the dispersion effect in addition to the power attenuation method, the spectral resolution of single charge is 0.01cm
^-1
. The feasibility of measurement dust charge based on infrared extinction theory is shown theoretically.