Simulations of beam-matter interaction experiments at the CERN HiRadMat facility and prospects of high-energy-density physics research

In a recent publication [Schmidt , Phys. Plasmas 21, 080701 (2014)PHPAEN1070-664X10.1063/1.4892960], we reported results on beam-target interaction experiments that have been carried out at the CERN HiRadMat (High Radiation to Materials) facility using extended solid copper cylindrical targets that were irradiated with a 440-GeV proton beam delivered by the Super Proton Synchrotron (SPS). On the one hand, these experiments confirmed the existence of hydrodynamic tunneling of the protons that leads to substantial increase in the range of the protons and the corresponding hadron shower in the target, a phenomenon predicted by our previous theoretical investigations [Tahir , Phys. Rev. ST Accel. Beams 25, 051003 (2012)1098-440210.1103/PhysRevSTAB.15.051003]. On the other hand, these experiments demonstrated that the beam heated part of the target is severely damaged and is converted into different phases of high energy density (HED) matter, as suggested by our previous theoretical studies [Tahir , Phys. Rev. E 79, 046410 (2009)PLEEE81539-375510.1103/PhysRevE.79.046410]. The latter confirms that the HiRadMat facility can be used to study HED physics. In the present paper, we give details of the numerical simulations carried out to understand the experimental measurements. These include the evolution of the physical parameters, for example, density, temperature, pressure, and the internal energy in the target, during and after the irradiation. This information is important in order to determine the region of the HED phase diagram that can be accessed in such experiments. These simulations have been done using the energy deposition code fluka and a two–dimensional hydrodynamic code, big2, iteratively.