Diagnostics of magnetized low temperature plasma by ball - pen probe

The ball-pen probe is an innovative electric probe for direct measurements of the plasma potential in magnetized hot plasma. This probe is based on the Katsumata probe concept. The ball-pen probe can adjust the ratio I-saturat(-)/I-saturat(+) of the electron and ion saturation currents to be equal to one and therefore the ball-pen probe characterization becomes symmetric. If this is achieved, the floating potential of the ball-pen probe is equal to the plasma potential in Maxwellian plasma. We show the application of a ball-pen probe in slightly magnetized low temperature plasma