Demonstration of a transient high gain soft x-ray laser for neon-like argon

We have demonstrated a high gain neon-like argon ion X-ray laser using a gas puff target. The elongated X-ray laser plasma column was produced by irradiating the gas puff target with line-focused double picosecond laser pulses with a total energy of 9 J in a travelling-wave excitation scheme. Strong lasing was observed, and a high gain coefficient of 18.7 cm-1 and a narrow beam divergence of less than 3.7 mrad were measured on the transient collisionally excited 3p1S0-3s1P1 transition for neon-like argon at 46.9 nm with targets up to 0.45 cm long. (author)