A novel thermal probe design for the measurement of energy influx in RF remote plasma

A novel design of a thermal probe to measure the energy influx of RF plasma has been achieved. This probe utilises one-dimensional steady-state conduction through the probe's cylindrical body and has the ability of controlling its exposed surface's temperature. The probe is fully instrumented so that the temperature field within it is known. This temperature field will serve as an indicator of achieving steady-state conduction as well as securing the needed data to calculate the energy influx of the RF plasma. Experimental results show that the plasma energy influx varied from 0.3 kW/m² to 2.2 kW/m² for RF power ranging from 15 W to 300 W, respectively. The variation of the energy influx with the RF power was found to follow a linear profile and a simple relation is proposed to model this variation for the considered plasma. Error analysis has been carried out to estimate the experimental uncertainties in the resulting energy influx values. The resulting uncertainties are found to be within the acceptable range for such applications.

► We developed a novel thermal probe to measure the energy influx in RF remote plasma. ► The steady state one dimensional conduction method was used. ► The variation of Ar - plasma heat influx with RF power HCD-L-300 system was found to follow a linear profile. ► The maximum experimental uncertainty that is associated with the energy influx measurement was found to be around 13%.