Fig. 1. Pre-pulse generating system.

Fig. 2. Variation of 46.9 nm laser intensity as a function of delay time for different discharge currents.

Fig. 3. Variation of 46.9 nm laser intensity as a function of delay time for different pre-discharge currents. The amplitude of the main discharge current was fixed at 30 kA.

Fig. 4. Variation of laser intensity as a function of pre-pulse current.

Fig. 5. Dependence of laser intensity on the initial filling pressure of Ar for two different delay times: (a) 30 kA, (b) 36 kA, and (c) 40 kA. The amplitude of pre-discharge current was set at 140 A throughout the experiment.

Fig. 6. Laser spots captured for different pre-discharge currents by utilizing a delay time of 8 μs. The main and pre-pulse currents were fixed at 30 kA and 140 A, respectively. The discharge pressure was set at 43 Pa for this experiment. The detection system is fixed at a distance of 170 cm from the capillary exit.