Numerical Simulation of Shock Wave Generation with KALIF

this paper have been described extensively in [4]. Thin foils of aluminum of different thicknesses were irradiated with KALIF beam. The velocity of rear surface was measured by the ORVIS system. Two types of experiments are analysed here: (1)F oil acceleration experiments : In these experiments, thin subrange (i.e. the thickness of the target was larger than the range of protons) aluminum foils of various thicknesses were irradiated by the KALIF beam. The back surface velocity was recorded with ORVIS. The thickness of the targets varied between 22 ¯ m and 75 ¯ m. (2)P ressure measurements : In these experiments the aluminum foils, whose thicknesses slightly exceeded the range of protons, were covered with LiF windows to avoid shock reflections. The impedance of LiF is approximately the same as that of aluminum. The velocity at the Al-LiF interface was recorded as a pressure signal. In our analysis we assume that the beam characteristics do not change appreciably from shot to shot. This assumption is justified for this analysis, because at present the electrical signals on the diodes were measured regularly and showed no major differences for successful shots. The total beam intensity was measured to characterise the beam power by nuclear diagnostics and Faraday cups. Because of the experimental constraints beam diagnostics cannot be performed together with the foil acceleration experiments. Mathematical Mode

A numerical parameter study of the beam-target interaction performed at KALIF

The Karlsruhe Target Code KATACO is used to simulate beam-target interaction experiments performed with the Karlsruhe Light Ion Facility KALIF. This report summarizes the main results of a numerical parameter study with different assumptions about the maximum power density of the KALIF diodes, the beam angle and energy distribution and the beam power rising and decreasing time. A discussion of the role of radiative transfer and two-dimensional effects is included. The calculations show that more detailed information is needed about the beam parameters at the target during individual KALIF shots for a better interpretation of single experiments. A simultaneous measurement of target velocities and temperatures of the generated ablation plasma is desirable. The two-dimensional simulations suggest the possibility to deduce information about the spatial beam profile of KALIF from spatially resolved measurements of the target velocity. (orig.)Available from TIB Hannover: ZA 5141(6106) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Investigations on physics and dynamics of matter with the Karlsruhe Light Ion Facility KALIF

In this report we present investigation on the dense plasma performed in the last few years at our light ion facility KALIF. Equation of state of matter in the region of strongly coupled plasma is investigated. The zone directly heated by the KALIF beam gets about 5 MJ/g of energy within first few 10's of ns. This launches a strong shock wave in the adjacent cold material. By suitably designing the target thin foils could be accelerated to velocities >12 km/s. The acceleration of flyer plate is not monotonic and shows several steps caused by shock wave reverberation within the flyer. Detailed analysis of this process gives clues about the equation of state of the matter. We have developed a Mie-Grueneisen type of equation of state that describe states of matter better than the previously available equation of states. Precise measurement of shock melting for a few materials is also presented. Further, spall strengths for some single- and polycrystalline materials have been measured at high strain rates in excess of 10"6s"-"1. Spall strength of single crystals exceed that of polycrystalline material by a factor of 2 to 3. (orig.)86 refs.Available from TIB Hannover: ZA 5141(5991) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman