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A proton radiography facility with the use of magnetic optics (PUMA proton microscope) has been developed at the TWAC-ITEP accelerator-accumulator facility (the ITEP terawatt accumulator) for measuring the substance density distribution inside static and dynamic objects using the proton beam with an energy of 800 MeV. The proton radiographic image of an object of investigation placed in the object plane of the setup is formed in the plane of the detector with magnification K = 4 with the aid of the magneto-optical system consisting of four quadrupole lenses on permanent magnets. The PUMA facility is intended for measuring objects with an areal density of up to 20 g/cm2 with a field of vision as large as 20 mm in diameter. The spatial resolution of radiographic images depends strongly on the areal density of the object of investigation. For the PUMA facility, the spatial resolution varies from 60 to 115 μm at an areal density of 0.46–17 g/cm2, respectively. The dynamical state of substance can be investigated in four consecutive radiographic images, since the time structure of the proton beam consists of four pulses, each with a duration of 47 ns (full width at half maximum (FWHM)) and an interval of 250 ns between them. This article is devoted to the description of the proton microscope construction. The main metrological characteristics of the facility are described using experiments with static and dynamic objects as an example.

This paper describes a fast multi-channel radiation pyrometer that was developed for warm dense-matter experiments with intense heavy ion beams at the Gesellschaft für Schwerionenforschung mbH (GSI). The pyrometer is capable of measuring brightness temperatures from 2000 K to 50,000 K, at six wavelengths in the visible and near-infrared parts of the spectrum, with 5 ns temporal resolution, and several micrometers spatial resolution. The pyrometer's spectral discrimination technique is based on interference filters, which also act as mirrors to allow for simultaneous spectral discrimination of the same ray at multiple wavelengths.

In this work release isentropes of shocked porous molybdenum were investigated. Samples with an initial porosity m = ρ0/ρ = 1.4 and 3.1 were studied to achieve near-critical entropy states of metal after shock compression. Compressed samples were expanded into helium with different initial pressures. The brightness temperature of the metal and the helium shock wave velocity were measured with a fast multichannel pyrometer. The helium shock wave velocity was used to determine the final pressure (P S) of expansion of the metal and the velocity of metal expansion (W S). Location of peculiarities on the P S–W S and P S–T P curves of the isentropes gives the location of their entrance into the two-phase region. Estimation of the molybdenum critical temperature and pressure was carried out on the basis of the experimental data.

Results of experiments on the expansion of shock-compressed nickel samples into helium are presented. An isentrope with an initial pressure of 170 GPa was studied. The radiance temperature of the nickel sample and the velocity of the shock wave, generated in helium, were measured by a fast multichannel optical pyrometer; other parameters, such as the particle velocity, the pressure on the He-Ni interface, and the temperature of He were calculated using He Hugoniot (chemical plasma model). To increase the shock entropy up to a near-critical value and to intensify the process of heat-mass transfer, porous samples were used. Final states with pressures below 1.5 GPa, determined by the initial He pressure, were generated. The isobaric overheat of nickel by hot shocked helium provided an information about the nickel liquid spinodal. The change in slope of an isentrope in the pressure-particle velocity plane allowed an estimate of the point of its entrance in the two-phase region. Estimates of the critical temperature and pressure were made from peculiarities of P-T path, using various models of the nickel liquid spinodal to represent experimental data.

The results of experimental investigation of near—critical point states of liquid‐vapour phase transition of of lithium, sodium and aluminium are presented. The metal foil samples were launched by explosively driven steel plate in Helium atmosphere; Li and Na—by direct impact and Al—by impact through the layer of helium. The heating of the Li and Na foils were performed by heat exchange with shocked He layer from the free side of sample; Al—by heating by multiple‐shocked He from the back side of the foil. The temperature of sample surface was measured by fast multi‐channel optical pyrometer. For Li and Na experiments the pressure was obtained from measured shock velocity in helium using base length technique; the 1‐D simulation of the process of launching was performed to obtain pressure for Al experiments. The obtained experimental information allowed to evaluate liquid spinodal line, and the position of critical points on pressure—temperature plane for investigated metals.

The results of temperature and conductivity measurements of hydrogen, multiple shock compressed to the pressures 135 and 180 GPa are presented. Explosively driven steel plate with velocity up to 8 km/s was used for shock wave generation. Hydrogen with various initial pressures and temperatures was multiple shock compressed between steel bottom and sapphire window. Brightness temperature of hydrogen was measured by fast optical pyrometer. Electrical resistance of shocked hydrogen was measured simultaneously with optical pyrometer records. The conductivity of hydrogen decreased from 424 1/Om/cm at 2700 K down to 20 1/Om/cm at 6000 K along 135 GPa isobar. The conductivity of hydrogen decreased from 800 1/Om/cm at 5000 K down to 100 1/Om/cm at 6700 K along 180 GPa isobar. Experimental results are compared with various theoretical predictions.

High-energy heavy ions are an ideal tool to generate homogeneously excited, extended volumes of nonthermal plasmas. Here, the high-energy loss (dE/dx) and absolute power deposition of heavy ions interacting with matter has been used to pump an ultraviolet laser. A pulsed 70 MeV/u 238U beam with up to 2.5 x 10(9) particles in approximately 100 ns beam bunches was stopped in a 1.2 m long laser cell filled with a 1.6 bar Ar-Kr-F2 mixture (typically 50%:49.9%:0.1%). Laser effect on the 248 nm KrF* excimer transition is clearly demonstrated.

In this work release isentropes of shocked porous molybdenum were investigated. Samples with initial porosity m=ρ0/ρ=1.4; 3.1 were used to achieve near‐critical entropy states of metal after shock compression. Shocked samples were expanding into helium with different initial pressures. The brightness temperature (TP) of metal and the velocity of shock wave in helium were measured by fast optical pyrometer. Shock wave velocity value allowed to determine the final pressure (PS) of expansion of metal and the velocity of metal expansion (WS). Location of peculiarities on isentropes in PS‐WS and PS‐TP diagrams gives the location of their entrance into two‐phase region. Estimation of molybdenum critical temperature and pressure were done on the basis of experimental data.

We present a new data on pyrometry measurements of SiO2-aerogel under shock loading. Optically transparent samples with initial densities 0.36, 0.27 and 0.008 g/cc was shocked up to 65 kJ/g total energy of schock compression; temperatures up to 25000 K was measured. The analysis of data is described.

Near critical point states of tin were generated by the expansion of shocked metal into helium to pressures of several kbars and less. Thermodynamic states on release isentropes originated from shock pressures of 137, 180, and 220 GPa were investigated. Gas dynamic parameters and temperature have been measured by the use of the method of optical pyrometry. The heating of tin on the boundary with shocked gas was described due to the difference between tin and gas temperatures. The problem of the interface heat transfer was solved to obtain the temperature of expanded tin. The point of intersection of experimental and theoretical curves for maximum overheat temperatures was used to estimate parameters of the critical point, which occurred at Pcrit=0.25 GPa, Tcrit=7850 K (dT=300K, dP=0.02 GPa). The result is in a good agreement with available evaluations of the critical point. Experimental data obtained have been used for construction of multi-phase wide-range equation of state for tin.

Two isentropes from lead shock states of 223 and 265 GPa have been traced in the pressure region below 0.6 GPa. Residual temperature and velocity of expansion into helium had been measured by optical pyrometry technique [1]. Fast heating of matter under investigation by shocked helium atmosphere was observed. Maximal overheat temperatures of liquid lead have been connected to ones of liquid spinodal. The experimental data were compared with the results of lead semiempiric wide-range equation of state [2]. It is proved, that critical point pressure was less then predicted nowadays, and critical point temperature in the range of uncertainties is the same in the framework of van-der-Waals model.

Results of the experiments on measurements of optical properties of strongly coupled hot plasmas are presented. The fast optical pyrometry enabled us to obtain information on the thermodynamic and optical properties of condensed matter in the supercritical region of parameters and in the vicinity of the saturation curve. The experimental information is compared with the wide-range semiempirical equation of states and optical models of plasma.