The response of a commercially available silica powder at low density to shock loading has been investigated. Hugoniot data were obtained for samples from two initial densities. The shock velocity particle velocity dependence was found to be linear for both densities. The data is modelled using a P-alpha model [1] and reported in a companion paper [2].

Spallation studies have proved invaluable in determining the spall strengths of these materials, which are then used for various assessment and design purposes. However, there are still many uncertainties regarding the spallation process, particularly in alloys, due to the difficulty in developing predictive constitutive and failure models for these materials. One difficulty is that the simulation results depend as much on the constitutive and fracture behaviour as the numerical treatment, particularly post failure. The purpose of this paper is to isolate these effects by using very well controlled data for Ti6Al4Vn alloy under a range of impact scenarios using VISAR. These experiments have been simulated using the Lagrangian hydrocode DYNA and the Eulerian hydrocode CTH. The study reinforces the view that the simulation of uniaxial spall signals, represents a significant challenge for the constitutive and fracture models, as well as the post failure numerical treatment within the hydrocode. The results of the simulations are discussed in the wider context of validation of constitutive and fracture models and the lack of real understanding concerning the spallation processes in these alloys.

Nuclear transport models are important tools for interpretation of many heavy-ion experiments and are essential in efforts to probe the nuclear equation of state. In order to fulfill these roles, the model predictions should at least agree with observed single-particle-inclusive momentum spectra; however, this agreement has recently been questioned. The present work compares the Vlasov-Uehling-Uhlenbeck model to data for mass-symmetric systems ranging from C-12 + C-12 to La-139 + La-139, and we find good agreement within experimental uncertainties at 0.4 A and 0.8 A GeV. For currently available data, these uncertainties are too large to permit effective nucleon-nucleon scattering cross sections in the nuclear medium to be extracted at a useful level of precision.

The reaction plane of high-multiplicity Au-Au collisions at 650, 400, 250, 150, and 75 MeV/nucleon was determined by measuring the transverse velocity of charged fragments. Measurements of the collective flow of charged fragments reveal that the onset of flow in high-multiplicity Au-Au collisions occurs at a finite beam energy below 60 MeV/nucleon.