Dependence of non thermal plasma temperature on the plasma needle conditions
IOSR Journal of Dental and Medical Sciences
An atmospheric pressure helium plasma needle type is studied. The plasma isgenerated at kHzat very low power levels. It is in contact with a single electrode and is part of a resonantelectric circuit. The plasma needle consists of glass tube and stainless steel tube concentrated inside it,they are used for guiding the gas flow. The stainless steel tube also serves as the electrode, which is connected to a high-voltage (HV) sub microsecond pulsed direct-current (dc) power supply (amplitudes of
... ly (amplitudes of up to 40 kV).The stainless steel tube is made with different outer diameters (2.7,3.5,5,6)mm and the glass tube was made with different inner diameters (1,4.4,5.3,10.6)mm, the non thermal plasma temperature was measured as a function of high voltage frequency (up to 30 kHz), and distance from the needle nozzle, for different flow rate of the gas (1, 2, 3, 4, 5) l/minfor every stainless steel tube, The helium gas temperature was measured with a digital thermocouple having the "hot" junction covered with a plastic-cap. It is found that the plasma temperature increases with increasing frequency up to given frequency (nearly 15 kHz)and then slow down with increasing frequency, also it is found the maximum temperature measured at the nozzle of the needle (d=0) and the slow down slowly with distance. It is found the diameter of the cylindrical electrode did not had significant effect on the temperature of the plasma.