A pump scheme with one long and two short pump pulses is proposed, in a grazing incidence pumping x-ray laser (XRL) configuration. A 360 ps long pulse, prepares a plasma in a low charge state. Then, an initial short pulse ionizes the plasma to an optimal charge state, while the second short pulse induces strong collisional excitation in the gain region. With only 200 mJ of pump energy on target, a compact Ag XRL at 13.9 nm with a gain coefficient

An ultrashort and ultraintense pulses combination method is proposed, based on the spectral combination of parallel laser pulses, with complementary spectra, in chirped pulse amplification (CPA) laser systems. In a proof-of-principle experiment, it is demonstrated that two long pulses of 330 fs can be overlapped in a collinear way, to produce a shorter pulse, of 190 fs. As a consequence, it is shown that the power for the combined pulse obtained

The effects of the incidence angle of the main pump (MP) pulse in non-normal pumping geometry and the influence of the MP duration are investigated experimentally and theoretically for a transient collisionally pumped (TCE) x-ray laser in Ni-like Zr at 45° and 72° incidence angle on the target. The way they transfer to the x-ray laser output depends on the preplasma conditions, most notably on the average ionization distribution at the arrival