Experimental study on measurements of plasma current and density in atmospheric pressure plasma jet

Summary form given only. Recently, plasma techniques under atmospheric pressure circumstances have been adapted for industrial, medical and biological applications. Atmospheric pressure plasmas, such as a plasma jet are typically produced using an arc discharge and a dielectric barrier discharge (DBD). The arc discharge produces a high-temperature plasma, whereas DBD produces a low-temperature plasma, which results in less thermal damage to materials. Atmospheric pressure plasma of DBD is generated intermittently using dielectric, rate gas and metal electrode by applying radio frequency and high voltage1. When it is used a quartz tube as a dielectric, plasma is released to the atmosphere. A plasma plume is a small bulletlike volume of plasma traveling at unusually high velocities2. We have studied a generation of high density plasma jet using focused plasma jets3. However, the detailed properties of the plasma current and density were still not estimated. In this work, we use helium plasma jet produced using a quartz tube and copper foil electrodes where a low frequency (~13 kHz) and a high voltage (-6 ~ +9 kV) are applied. The measurement of plasma current is used by a current probe. The plasma drift velocity is measured indirectly by the drift velocity of luminous bullet on the time of flight method. The plasma cross-section is estimated on the photographs. The plasma density is evaluated from these measurements values. The dependences of plasma current and density on the helium gas flow rate are examined. Detail experimental results and discussion will be presented at the conference.