Towards high photon-number soft x-ray lasers

We present an experimental design to independently pump two soft X-ray laser media suitable for a seed-amplifier configuration. Both the seed and the amplifier target are operated in the TCE scheme utilizing the DGRIP technique with its intrinsic travelling wave excitation. Controlled injection of the seed X-ray laser into the amplifier medium is realized via a spherical XUV mirror. The experimental design is perfectly appropriate for benchmarking combined simulations of the ARWEN and DeepOne code. A first experiment at the PHELIX laser utilizing this scheme has been conducted, demonstrating signs of amplification and allowing for the direct measurement of the gain life time of a Ni-like silver SXRL.