A. Kozyreva

Time-resolved energy loss spectroscopy of energetic heavy ion beams generating a dense plasma

Abstract At the Gesellschaft fur Schwerionenforschung (GSI) Darmstadt, intense beams of energetic heavy ions have been used to generate hot dense plasmas by impact on solid targets. Recently, we have measured time evolution of the energy loss of intense beams (109–1010 particles/pulse) of 190 MeV/u 238 U as well as of 300 MeV/u 86 Kr in cryogenic crystals of neon and xenon, respectively. For this purpose, a new time resolving energy loss spectrometer has been set up. We observed continuous reduction in the energy loss due to hydrodynamic motion of the ion beam heated target matter. These are the first measurements of this kind. Two-dimensional hydrodynamic simulations were also carried out using the above beam and target parameters. Good agreement has been found between the experimental results and the simulations.

Creation of strongly coupled plasmas using intense beams of 400 MeV/u uranium ions to be generated at the Gesellschaft für Schwerionenforschung (GSI) Darmstadt SIS-200

The heavy ion synchrotron, SIS-18 (that has an 18 Tm magnetic rigidity), at the Gesellschaft fur Schwerionenforschung (GSI), Darmstadt is a unique facility worldwide that delivers intense beams of energetic heavy ions. The GSI has plans to extend its accelerator capabilities by building a new synchrotron (SIS-200) with a much higher magnetic rigidity of 200 Tm. According to the preliminary design considerations, the SIS-200 will generate a uranium beam that will consist of at least 1012 particles and that will be delivered in a 50 ns long pulse. This beam will be used to study various interesting problems, including fragmentation of the projectile ions while passing through solid matter and creation of high-density, strongly coupled plasmas. For the former type of studies, a particle energy of 1 GeV/u has been considered to be appropriate, while for the latter case, a lower value of 400 MeV/u has been found to be most suitable. In this paper we present, with the help of two-dimensional numerical simulatio...

Metallization of hydrogen using heavy ion imploded multi-layered cylindrical targets

This paper shows with the help of two-dimensional hydrodynamic simulations that it may be possible to achieve theoretically predicted physical conditions required for hydrogen metallization in heavy ion imploded multi-layered cylindrical targets. These include a density of about 1 g/cm 3 , a pressure of 2-5 Mbar and a temperature of a few 0.1eV in the compressed hydrogen sample. In this study an intense uranium beam consisting of 10 12 ions having a particle energy of 400 MeV/u is considered. The ions are delivered in a single bunch that has a length of 50 ns. These beam parameters are the design parameters for the future 200 Tm synchrotron facility, SIS-200, that will be constructed at the Gesellschaft fur Schwerionenforschung (GSI), Darmstadt.

Fundamental studies of intense heavy-ion beam interaction with solid targets

Intense (10/sup 11/ particles/1 /spl mu/s /spl sim/300 MeV/u) heavy ion beams are generated in the heavy-ion synchrotron (SIS) of the GSI-Darmstadt facility. Large volumes of strongly coupled plasmas are produced by heavy ion beam interaction with solid targets, with plasma densities close to the solid state, pressures of about 100 kbar, and temperatures of up to 1 eV, with relevance for equation of state (EOS) of matter, astrophysics, and low-entropy shock compression of solids. The plasmas created by ion beam interaction with metallic converters and cryogenic crystals were studied by backlighting shadowgraphy and by time-resolved spectroscopy in the visible and vacuum ultraviolet ranges. Low entropy weak shock waves induced by the ion beams in the metal-plexiglass multilayered targets were visualized by time resolved schlieren measurements, revealing induced multiple shockwaves with pressures higher than 15 kbar in a plexiglass window and propagation velocities up to 35% higher than the speed of sound in plexiglass at room temperature. To get an insight into the plasma dynamics, both types of experiments are simulated by the BIG-2 two-dimensional hydrodynamic code.

Designing future heavy-ion-matter interaction experiments for the GSI Darmstadt heavy ion synchrotron

Abstract Using a two-dimensional hydrodynamic simulation model, we present optimized design for a number of heavy-ion–matter interaction experiments that will be performed at the upgraded GSI Darmstadt accelerator facility. Our simulations show that using suitable beam–target configurations, one should be able to create samples of high-energy-density matter that could be used to investigate the equation-of-state properties of matter under such extreme conditions. Moreover, it has been shown that by imploding multi-layered cylindrical targets using the upgraded GSI beam, one may be able to create metallic hydrogen.

Studies of high energy density in matter driven by heavy ion beams in solid targets

By the interaction of intense (10 10 particles/500 ns) relativistic (∼300 MeV/amu) heavy ion beams with solid targets, large volumes (several cubic millimeters) of strongly coupled plasmas are produced at solid-state densities and temperatures of up to 1 eV, with relevance for equation-of-state (EOS) studies of matter at high energy density and heavy ion-beam-driven inertial confinement fusion (ICF). The time and space profile of the ion beams, focused by the plasma lens to diameters of a minimum of 0.5 mm in order to obtain specific energy depositions of up to about 4 kJ/g, were measured to calculate the energy deposition in the target. In the present work, the plasmas created by ion beam interaction with cryogenic gas crystals and metallic targets are studied, among other methods, by backlighting shadow-graphy and electrical conductivity measurements. The experiments are coupled with two-dimensional hydrodynamic simulations.

Influence of hydrodynamic expansion on specific power deposition by a heavy ion beam in matter

In this paper, we show with the help of two-dimensional numerical simulations that the specific power deposition by a heavy ion beam in matter may significantly decrease due to hydrodynamic expansion of the target during irradiation. It has also been shown that in order to maximize the specific energy deposition, one is required to determine an optimum set of beam and target parameters including ion energy, beam radius, and pulse length. Three different values for the beam radius, namely, 0.5, 1.0, and 1.5 mm are considered, respectively. The target is a solid lead cylinder, which is irradiated by a uranium beam that consists of 1012 ions with a particle energy of 400 MeV/u. Such beam parameters will be available at the future heavy ion synchrotron, SIS-200 (with a magnetic rigidity of 200 Tm) at the Gesellschaft fur Schwerionenforschung (GSI), Darmstadt. It is also assumed that the beam is incident on one face of the cylinder and the cylinder length is less than the range of the projectile ions. The ions...

Experimental investigations of multiple weak shock waves induced by intense heavy ion beams in solid matter

The dynamics of low entropy weak shock waves induced by heavy ion beams in solid targets was investigated by means of a schlieren technique. The targets consist of a metallic absorber for the beam energy deposition followed by a plexiglass block for optical observations. Multiple waves propagating with supersonic velocities at 15 kbar pressures were observed in the plexiglass, for pressures of up to 70 kbar numerically calculated in the absorbers. Pressures in the megabar ranges are predicted for a near future beam upgrade, enabling studies of phase transition to metallic states of H, Kr, and Xe.

High Density Neon‐Plasma Created by Intense Gold Beams

The expansion of a heavy ion beam heated lead pusher has been utilized to compress solid cryogenic neon. Diagnostics have been developed to measure the equation of state parameters and transport coefficients. Advanced compression schemes for two-dimensional compression have been prepared.