H. Daido et al., Experimental characterization of short-wavelength Ni-like soft-x-ray lasing toward the water window, J OPT SOC B, 16(12), 1999, pp. 2295-2299
We report experimental results of studies of Ni-like x-ray lasing at wavele
ngths as short as 4.5 nm. The performance of x-ray lasing pumped by various
types of pulse train that were composed of 100-ps pulses was investigated
with a double-slab target placed in series to double the gain length. Two o
pposing laser beams separated by an appropriate time difference irradiated
the double targets for quasi-traveling-wave pumping. Well-collimated double
-target amplification was successfully demonstrated for Yb and Hf lasing at
5.0 and 4.7 nm whose gain-length products were 11 and 6, respectively. The
Ni-like lasing lines of Ta have also been observed at 4.5 nm. (C) 1999 Opt
ical Society of America [S0740-3224(99)01112-1].