A table‐top collisional Ni‐like Ag X‐ray laser at 13.9 nm pumped by single picosecond laser pulse

The saturated operation of a soft X‐ray laser in Ni‐like Ag at 13.9 nm pumped by a single profiled picosecond laser pulse with the length of 6 ps has been demonstrated. The pump energy of 3 J used for lasing in this scheme is equal to half of the minimum energy applied in the previously reported experiments. Small signal gain coefficient as high as 33 cm−1 has been estimated from the data. The influence of the pump beam characteristics on the output is discussed as well.