HHT (High energy, High Temperature) is a unique experimental area at GSI designed for High Energy Density Physics (HEDP) experiments with intense ion beams delivered by SIS-18 heavy ion synchrotron. The HHT beam line is equipped with a strong Final Focus System which allows to focus intense beams of various ion species up to Uranium with ion energy 50 - 1000 MeV/u to a spot size of 0.15 - 2.5 mm diameter. The pulse duration is 100 - 1400 ns and different pulse time shapes are available (single bunch, four bunches, flat top).

Typically, for HEDP and for so-called warm dense matter (WDM) experiments a beam of ²³⁸U⁷³⁺ ions with the energy 300-400 MeV/u is used. Presently, up to 4·10⁹ ions is delivered by the SIS-18 synchrotron in 70 - 300 ns long bunches. Taking full advantage of the electron cooler of SIS-18, such intense uranium beams can be focused to a spot of less than 300 µm (FWHM) at the target. Assuming a solid metallic target, the specific energy deposition in the target material is from a few kJ/g to ~ 50 kJ/g. This correspond to temperatures of 1-10 eV and pressures in the multi-kbar to sub-Mbar range incuced in a solid density sample with mm²-size. The parameters of the ion beam available at HHT are given in the table above.