I. V. Lomonosov

Unique capabilities of an intense heavy ion beam as a tool for equation-of-state studies

Intense heavy ion beams open new possibilities in high-energy-density matter research. Due to the unique feature of the energy deposition process of heavy ions in dense matter (volume character of heating) it is possible to generate high entropy states in matter without the necessity of shock compression. Previously, such high entropy states could only be achieved by using the most powerful shock wave generators, like nuclear explosions or powerful lasers. In this paper this novel technique of heavy ion heating and expansion is proposed to explore new fascinating regions of the phase diagram, including the liquid phase, the evaporation region with the critical point, and strongly coupled plasmas.

Ultrahigh compression of water using intense heavy ion beams: laboratory planetary physics

Intense heavy ion beams offer a unique tool for generating samples of high energy density matter with extreme conditions of density and pressure that are believed to exist in the interiors of giant planets. An international accelerator facility named FAIR (Facility for Antiprotons and Ion Research) is being constructed at Darmstadt, which will be completed around the year 2015. It is expected that this accelerator facility will deliver a bunched uranium beam with an intensity of 5x10(11) ions per spill with a bunch length of 50-100 ns. An experiment named LAPLAS (Laboratory Planetary Sciences) has been proposed to achieve a low-entropy compression of a sample material like hydrogen or water (which are believed to be abundant in giant planets) that is imploded in a multi-layered target by the ion beam. Detailed numerical simulations have shown that using parameters of the heavy ion beam that will be available at FAIR, one can generate physical conditions that have been predicted to exist in the interior of giant planets. In the present paper, we report simulations of compression of water that show that one can generate a plasma phase as well as a superionic phase of water in the LAPLAS experiments.

Impact of 7-TeV∕c large hadron collider proton beam on a copper target

The large hadron collider (LHC) will allow for collision between two 7TeV∕c proton beams, each comprising 2808 bunches with 1.1×1011 protons per bunch, traveling in opposite direction. The bunch length is 0.5ns and two neighboring bunches are separated by 25ns so that the duration of the entire beam is about 89μs. The beam power profile in the transverse direction is a Gaussian with a standard deviation of 0.2mm. The energy stored in each beam is about 350MJ that is sufficient to melt 500kg of copper. In case of a failure in the machine protection systems, the entire beam could impact directly onto an accelerator equipment. A first estimate of the scale of damage resulting from such a failure has been assessed for a solid copper target hit by the beam by carrying out three-dimensional energy deposition calculations and two-dimensional numerical simulations of the hydrodynamic and thermodynamic response of the target. This work has shown that the penetration depth of the LHC protons will be between 10 and ...

Metastable States of Liquid Tungsten Under Subsecond Wire Explosion

A numerical simulation of the initial stage of tungsten wire self-heating by a high-power microsecond current pulse was carried out. A wide-range semiempirical equation of state to account for the effects of melting and evaporation of tungsten at high temperatures was used. The metastable states were included in the process model, and the results of the simulation are in good agreement with experimental data.

Metastable States of Liquid Metal under Conditions of Electric Explosion

The paper deals with the simulation of the initial stage of tungsten wire explosion under the effect of a high-power nanosecond current pulse. The calculations involve the use of a semiempirical equation of state for tungsten, which allows for the effects of melting and evaporation at high temperatures. The laws of conservation that take into account the presence of a magnetic field and relative motion of the media are written at the liquid–vapor interface. It is demonstrated that a description fitting adequately the available experimental data is possible if one takes into account the possibility of realizing metastable states of liquid metal in the process of evolution of the system.

Database on Shock‐Wave Experiments and Equations of State Available via Internet

The information on thermodynamic properties of matter at extremely high pressures and temperatures is very important both for fundamental researches and applications. We have collected about 14000 experimental points on shock compression, adiabatic and isobaric expansion and measurements of sound velocities behind the shock front for more than 400 substances. The database with graphical user interface containing experimental data, approximation modules, and caloric equations of state models has been worked out. One can search the information in the database in two different ways and obtain the experimental points in tabular or plain text formats directly via the Internet using common browsers. Registered users can remotely add new data into the database. It is also possible to draw the experimental points on graphs in comparison with different approximations and results of equation‐of‐state calculations. Recently we have added an ability to make calculations of shock Hugoniots, isentropes, isobars, and ot...

Numerical study of converging shock waves in porous media

The dependences of the solutions to the hydrodynamic equations of compressed media that describe converging shock waves on the density of a substance ahead of a wave front are studied. The properties of Hugoniot adiabats that can explain the qualitatively different characters of these dependences for the equations of state of perfect gas and condensed matter are analyzed. The one-dimensional problems of converging shock waves in graphite and aluminum are considered, and the two-dimensional problem of the compression of graphite in a steel target with a conical cavity is solved. The latter problem is also investigated in terms of a simple model for a deformable solid that takes into account shear stresses.

Energy loss dynamics of intense heavy ion beams interacting with solid targets

At the Gesellschaft fur Schwerionenforschung (GSI, Darmstadt) intense beams of energetic heavy ions have been used to generate high-energy-density (HED) state in matter by impact on solid targets. Recently, we have developed a new method by which we use the same heavy ion beam that heats the target to provide information about the physical state of the interior of the target (Varentsov et al., 2001). This is accomplished by measuring the energy loss dynamics (ELD) of the beam emerging from the back surface of the target. For this purpose, a new time-resolving energy loss spectrometer (scintillating Bragg-peak (SBP) spectrometer) has been developed. In our experiments we have measured energy loss dynamics of intense beams of 238 U, 86 Kr, 40 Ar, and 18 O ions during the interaction with solid rare-gas targets, such as solid Ne and solid Xe. We observed continuous reduction in the energy loss during the interaction time due to rapid hydrodynamic response of the ion-beam-heated target matter. These are the first measurements of this kind. Two-dimensional hydrodynamic simulations were carried out using the beam and target parameters of the experiments. The conducted research has established that the ELD measurement technique is an excellent diagnostic method for HED matter. It specifically allows for direct and quantitative comparison with the results of hydrodynamic simulations, providing experimental data for verification of computer codes and underlying theoretical models. The ELD measurements will be used as a standard diagnostics in the future experiments on investigation of the HED matter induced by intense heavy ion beams, such as the HI-HEX (Heavy Ion Heating and EXpansion) EOS studies (Hoffmann et al., 2002).

Equation of state for liquid metals

Equations of state for metals based on the soft-sphere model are presented. Parameters of the soft-sphere potential are found. Binodals with critical points, isobars, shock adiabats, and release isentropes are calculated. Comparison of the results with available experimental data is made. Monte-Carlo simulation at constant pressure is carried out with obtained parameters. The results are in a good agreement with semiempirical isobar calculations.

Generation of warm dense matter and strongly coupled plasmas using the High Radiation on Materials facility at the CERN Super Proton Synchrotron

A dedicated facility named High Radiation on Materials (HiRadMat) is being constructed at CERN to study the interaction of the 450 GeV protons generated by the Super Proton Synchrotron (SPS) with fixed solid targets of different materials. The main purpose of these future experiments is to study the generation and propagation of thermal shock waves in the target in order to assess the damage caused to the equipment, including collimators and absorbers, in case of an accident involving an uncontrolled release of the entire beam at a given point. Detailed numerical simulations of the beam-target interaction of several cases of interest have been carried out. In this paper we present simulations of the thermodynamic and the hydrodynamic response of a solid tungsten cylindrical target that is facially irradiated with the SPS beam with nominal parameters. These calculations have been carried out in two steps. First, the energy loss of the protons is calculated in the solid target using the FLUKA code [Fasso et...