Fig. 1. Process of capillary discharge. The main pulse current was reduced by a factor of about 1000.

Fig. 2. Main pulse used in the experiment.

Fig. 3. Plane–plane resonator of 46.9 nm laser.

Fig. 4. Pulse obtained from the 46.9 nm laser with a resonator.

Fig. 5. Schematic of the plasma column: x-ray A is representative of the x-rays emerging from the side near the end face of the plasma column, and x-ray B is representative of the x-rays emerging from the end face.

Fig. 6. Laser pulses at Δt = 40 µs with and without a resonator with an initial pressure of 17 Pa.

Fig. 7. Laser spots at Δt = 40 µs: (a) without and (b) with a resonator with an initial pressure of 17 Pa.

Fig. 8. Radial distribution curves of output laser spots with and without a resonator.

Fig. 9. Output laser pulses at Δt = 50 and 60 µs with a resonator.

Fig. 10. Laser spots at Δt = 40 µs (a) and 50 µs (b) without a resonator.