Generation of a transient short pulse X-ray laser using a traveling-wave sub-ps pump pulse

This paper summarises the main results obtained during the two experimental campaigns on TCE X-ray lasers that we have carried out since the last Kyoto X-ray laser Conference in 1998. A two-color (2ω/1ω) pumping configuration was tested and led to the observation of a strong lasing line at 16 nm, identified to a 4f-4d transition in Ni-like Ag. A strong x 300-400 enhancement of the 13.9 nm Ni-like 4d-4p lasing emission was obtained when a traveling wave short pulse pumping was applied. Finally the temporal history of the 13.9 nm laser pulse was measured with a high-resolution Streak camera. A very short, 2 ps X-ray laser pulse was directly demonstrated for the first time.