Experiments on heating of low density CHO-foams by soft X-rays

Experiments, which use a combination of the PHELIX laser kJ-option and the heavy ion beam of 4-10 MeV/u energy delivered by the UNILACaccelerator, are aimed at investigation of the heavy ion energy loss in ionized matter. In these experiments a large scale (~1mm) long living (~5ns) high density plasma target with homogeneously distributed plasma density, temperature and ionization degree is required. The time is defined by the duration of the heavy ion bunch of 3 ns, the spatial size of the plasma target by the diameter of the heavy ion beam of ~ 0.5 mm. Highly homogeneous and slowly expanding plasma can be obtained when a low-density foam layer is volumetrically heated by soft X-rays. The indirectly heated laser target design for combined heavy ion beam laser experiments was proposed by Vatulin and Vasina [1]. In this scheme the laser interacts with the gold wall of the cylindrical converter (a primer hohlraum) where the laser energy is effectively converted into the soft X-rays with spectral distribution close to the Planckian one. Hohlraum generated X-rays heat volumetrically a lowdensity foam which serves as a plasma target for probing with heavy ion beams.