Short soft x-ray sources

In this work we report on the characterization of pulsed soft x‐rays emitted from laser‐produced plasma. The plasma was generated by a pulsed KrF excimer laser focused on pure Si, Cu and Ta targets by 40, 80 and 120 mJ laser energies. The utilized detector was a very sensitive Faraday cup which opportunely biased was able to record time‐resolved signals of x‐rays and to estimate their energy. The found x‐rays energy values were compared with the ion temperature of the plasma obtained by fitting the time‐resolved ion current signals with a shifted Maxwell‐Boltzmann velocity distribution. The results showed that the laser‐produced Ta plasma induced bunches of x‐rays having in average the highest energy values and it was also characterized by ion temperature higher than the ones of the laser‐produced Si and Cu plasmas. Copyright © 2009 John Wiley & Sons, Ltd.