Investigation of interactions of soft x-ray laser pulses with matters

Soft x-ray laser (SXRL) pulses were irradiated to the LiF, Al, and Cu surfaces. On all irradiated target surfaces, the surface modifications caused by the SXRL pulse irradiations were confirmed. However, the optical emission (visible range) from the surfaces during the pulse irradiations were not observed. The model calculation for the interaction between SXRL pulse and metal surface reveals the spallative ablation of target surface without plasma production. The experimental result investigated by our study is consistent with the theoretical calculations.