Fig. 1. Schematic of the plasma generator and the setup for laser diode absorption spectroscopy. LD, laser diode; SP, monochromator; PMT, photomultiplier tube; CCPS, capacitor charging power supply; MOSFET, metal-oxide-semiconductor field-effect transistor.

Fig. 2. Typical traces of pulsed voltage and current with gas mixture of 1% Ar/He at 800 mbar, of which the deposited energy is about 2.1 mJ. CCPS is set at 800 V, with the voltage at C1 and C2 charged to 1.33 kV.

Fig. 3. Plasma photos taken along the (a) y direction and (b) x direction at 800 mbar. Two segmented electrodes were used each with a length of 25 mm in the x direction and a width of 8 mm in the y direction.

Fig. 4. (a) Curves of Ar (1s⁵) density versus time at different DC charging voltages and 800 mbar. An absorption length of 8 mm was used. (b) Voltage at the output of pulsed DC power supply at different DC charging voltages and 800 mbar.

Fig. 5. Dependence of Ar (1s⁵) density on pressure. CCPS is set at 800 V. An absorption length of 8 mm was used.

Fig. 6. Time-resolved intensity of characteristic emission of Ar atoms at 800 mbar. The DC charging voltage is 750 V.