Tahir N A, Hoffmann D H, Maruhn J A, Spiller P, Bock R
Institut für Kernphysik, Technische Universität Darmstadt, Schlossgarten Strasse 9, 64289 Darmstadt, Germany.
Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 1999 Oct;60(4 Pt B):4715-24. doi: 10.1103/physreve.60.4715.
It is expected that after the completion of a new high current injector, the heavy-ion synchrotron (SIS) at the Gesellschaft für Schwerionforschung (GSI) Darmstadt will accelerate U(+28) ions to energies of the order of 200 MeV/u. The use of a powerful rf buncher will reduce the pulse length to about 50 ns, and employment of a multiturn injection scheme will provide 2 x 10(11) particles in the beam that correspond to a total energy of the order of 1 kJ. This upgrade of the SIS, hopefully, will be completed by the end of the year 2001. These beam parameters lead to a specific power deposition of the order of 1-2 TW/g in solid matter that will provide temperatures of about 10 eV. Such low specific power deposition will induce hydrodynamic effects in solid materials, and one may design appropriate beam-target interaction experiments that could be used to investigate the equation of state of matter under extreme conditions. The purpose of this paper is to propose suitable target designs with optimized parameters for the future GSI experiments with the help of one and two-dimensional hydrodynamic simulations. Cylindrical geometry is the natural geometry for highly focused ion beams, and therefore cylindrical targets are the most appropriate for this type of interaction experiments. The numerical simulations presented in this paper show that one can experimentally measure the characteristic sound speed in beam heated targets which is an important physical parameter. Moreover, one can study the propagation of ion-beam-induced shock waves in the solid materials. Different values for the specific power deposition, namely, 10, 25, 50, and 100 kJ/g, have been used. In some cases the pulse length is assumed to be 40 ns while in others it is considered to be 50 ns. Various materials including lead, aluminum, and solid neon have been used.
预计在一台新的强流注入器建成后，位于达姆施塔特的重离子研究协会（GSI）的重离子同步加速器（SIS）将把U(+28)离子加速到约200 MeV/u的能量。使用强大的射频聚束器将使脉冲长度缩短至约50 ns，采用多圈注入方案将使束流中含有2×10(11)个粒子，其总能量约为1 kJ。SIS的这一升级有望在2001年底完成。这些束流参数导致在固体物质中的比功率沉积约为1 - 2 TW/g，这将产生约10 eV的温度。如此低的比功率沉积将在固体材料中引发流体动力学效应，人们可以设计合适的束流 - 靶相互作用实验，用于研究极端条件下物质的状态方程。本文的目的是借助一维和二维流体动力学模拟，为未来GSI的实验提出具有优化参数的合适靶设计。圆柱几何形状是高聚焦离子束的自然几何形状，因此圆柱靶最适合此类相互作用实验。本文给出的数值模拟表明，人们可以通过实验测量束流加热靶中的特征声速，这是一个重要的物理参数。此外，人们可以研究离子束诱导的冲击波在固体材料中的传播。使用了不同的比功率沉积值，即10、25、50和100 kJ/g。在某些情况下，脉冲长度假定为40 ns，而在其他情况下则认为是50 ns。使用了包括铅、铝和固态氖在内的各种材料。
