LIF-Dip Measurement of Asymmetric Sheaths on a Planar Probe in a Pulsed Glow Discharge Electron Source

We present results from modified LIF-Dip measurements of electric field distributions in the sheaths formed on both sides of a planar probe inserted into a glow discharge. The plasma is generated inside a hollow anode, and an electron beam is extracted at one end of the discharge tube through a grid. The probe is oriented perpendicular to the tube axis and positioned at the discharge center inside the hollow anode. With the probe biased negatively, we measure the ion sheath electric field profiles above and below the probe in a single acquisition using the modified LIF-Dip method [1]. Complementary probe I-V characteristics were recorded to identify the plasma potential and to confirm operation in the ion-saturation regime during the LIF-Dip measurements.