A technique for measuring the spatial heterogeneity of the light yield of a proton radiography scintillator has been developed. It is based on the recording of digital images formed during the passage of a proton beam through a scintillator and the approximation of the intensity distribution in the beam cross section by a two-dimensional Gaussian-like function. The results of the spatial calibration of the light yield of a lutetium silicate scintillator obtained using a magneto-optical proton microscope PUMA are presented. It is shown that accounting of the spatial heterogeneity of the scintillator makes it possible to describe the transverse beam intensity at each point of the proton radiographic image with a mean accuracy of about 0.7%. Experimental data on fluctuations in the position of the beam center, its size, and shape in the scintillator plane of PUMA microscope were obtained. The proposed technique eliminates optical artifacts in the radiographic image caused by operation of the optical recording system and artifacts caused by the electron-optical shutter, provided that the signal is proportional to the intensity of the beam. It also eliminates or strongly suppresses optical artifacts in radiographic images due to changes in the efficiency of a charge-coupled digital camera.

A method has been developed for calculating the proton beam transmission of static objects with a quasi-uniform areal density from a single proton radiography image under the condition of a Gaussian-like transverse beam profile. The calculated images of the transmission are intended to reconstruct the density of the investigated objects. A proton radiography of static targets was performed on an experimental setup with special magnetic optics PUMA with a proton energy of 800 MeV and an intensity of 1010 particles per image. It is shown that the application of the method makes it possible to reconstruct the proton beam transmission of the object under study with an average relative error of approximately 1–1.2

The transmittance coefficient of silicon samples exposed to radiation of intense shock waves in xenon is measured. Shock waves are generated using the energy of condensed explosives. The intensity of radiation transmission at a wavelength of 1500 nm is measured by pyrometric methods. A model of the process based on the appearance of an absorbing layer in silicon due to photoionization is proposed.

In this study, the brightness temperatures of silicon shock-compressed to a pressure of P = 68 GPa and the evolution of its temperature during unloading are measured. The measurements were carried out in the infrared range Δλ1 = 1.1–1.7 µm, in which silicon is optically transparent, and in the visible range Δλ2 = 0.32–1.06 µm. The isentropic unloading of shock-compressed silicon into a vacuum is accompanied by an anomalous increase in the observed temperature.

The shock compressibility of single-crystal silicon is experimentally studied in the pressure range of 280 to 510 GPa. Shock waves are created using Mach's explosive cumulative generators. The parameters of shock waves are determined by the impedance matching method, and single-crystal quartz is used as a ref-erence substance. The results agree well with the ab initio calculation results and with the data obtained using laser shock waves.

For the first time, a new ceramic “Ideal,” a diamond-silicon carbide composite obtained in the reaction-diffusion Turing process, which makes it possible to obtain materials with the optimal set of physical and mechanical properties, is studied. An elastic-brittle fracture related to the propagation of a shock wave in a two-component system is noted. The dynamic elastic limit, determined by the properties of silicon carbide, is found to be 13.4 GPa. Its dynamic elastic limit and spall strength in the region of the elastic deformation are measured. The impact compressibility of ceramics up to a pressure of 625 GPa is determined.

This review is dedicated to the scientific research carried out by Academician V.E. Fortov at the Institute of Problems of Chemical Physics of the Russian Academy of Sciences (IPCP RAS) in Chernogolovka, where in 1971 he began his work after defending his candidate's dissertation. Here, Fortov studies the generation, physical properties, and gas dynamics of nonideal low-temperature plasma. Intensive experimental and theoretical studies of the compressibility, electrical conductivity, and optical properties of such a medium are published in a number of central journals, such as Physics-Uspekhi, Journal of Exper-imental and Theoretical Physics, Doklady Akademii Nauk, and High Temperature. In 1977, Fortov defended his doctoral dissertation "Investigation of Nonideal Plasma by Dynamic Methods." After the defense, his research on nonideal plasma and processes under the effect of powerful shock waves expanded significantly. Experiments were carried out on the explosive generation of neutrons and the reflective properties of powerful shock waves, and the processes of converting explosion energy into electromagnetic energy were studied by him. Particular attention was paid to the processes of metallization of hydrogen and inert gases, and a plasma phase transition in deuterium was discovered by him. This review attempts to briefly summarize Fortov's studies on nonideal plasma generated by an explosion and demonstrate the logic of their occurrence.

Measurements of the brightness temperature and compressibility of a dense silicon plasma formed by powerful shock waves (SWs) passing through a single-crystal sample have been carried out. Plane SWs were created using an explosive technique: the traditional plane acceleration of a steel driver plate made it possible to obtain pressures in silicon up to 133 GPa, and the use of "Mach" cumulative generators realized the pressures up to 510 GPa. The shock Hugoniot of silicon was determined by the impedance matching with alpha-quartz as the reference. The intensity of emitted thermal radiation was measured in the infrared range lambda similar to 1.5 mu m, where silicon is optically transparent, and in the visible range of the spectrum. A significant (up to five times) understatement of the measured values of the brightness temperature in comparison with the values calculated by the equation of state was found. Taking into account the reflective properties of the SW in silicon does not lead to an agreement with the experiment. The estimates of relaxation processes behind the shock front suggest the presence of a zone of the establishment of ionization equilibrium with a width of similar to 10 mu m.

New results of measurements of s- and p-polarized reflectivity of nonideal plasma at the frequency of the external electromagnetic field ν las = 2.83 × 10 14 s −1 , free-electron number density n e = 3.3 × 10 21 cm −3 (Coulomb nonideal plasma parameter Γ = 1.2) and n e = 5.2 × 10 21 cm −3 (Γ = 1.4) are presented. These data are the result of the next stage of study of optics of a warm dense matter. We present a microscopic approach to describe the entire set of experimental data on the optics of strongly correlated plasma.

Experimental estimates of the process of the ejection of particles and the formation of plasma during the shock wave exits on the free surface of the cooper sample studied were carried out. The radiation intensity was recorded by a three-channel pulsed pyrometer in an experimental assembly with lateral observation. When the impactor speed was about 5 km/s, a stream of particles and plasma flew from the target surface, the front speed of which reached 12.5 km/s.

The article describes possible experiments with explosively driven non-ideal plasma at the proton microscope at the Facility for Antiprotons and Ion Research. It is proposed to employ linear explosive tubes for plasma generation and to measure an areal density in shock-compressed plasma of argon and xenon. The proposed experiments will provide valuable information on influence of strong interparticle interactions on thermodynamic properties of strongly coupled plasma. The density measurement will help the researchers to understand the nature of wall and wire precursors arising in the shock tubes.

An analysis of the response of a dense plasma to electromagnetic waves of moderate intensity can be used as a tool to study the validity of physical models describing the behavior of matter in extreme conditions. Within this work, the new experimental data are presented on oblique incidence of polarized electromagnetic wave. The study of polarized reflectivity properties of nonideal xenon plasma was accomplished using laser light at νlas = 2.83 × 1014 s−1. The measurements of polarized reflectivity coefficients of explosively driven dense plasmas have been carried out at incident angles up to θ = 70° for plasma density ρ = 1.8 g/cm3. The simple model of the ionization kinetics of the plasma transition region is considered.

Optical experimental data for non-ideal plasma are very important for validating theoretical models and fitting them to actually observed constraints. Within this work, new data on oblique incidence of polarized electromagnetic wave are presented. The study of polarized reflectivity properties of nonideal xenon plasma was accomplished using laser light at wavelength λlas = 1064 nm and plasma density ρ = 1.8 g/cm3. Angular dependences of s- and p-polarized reflectivities were used in the integration of Maxwell equations to construct the spatial profile of the density of charge carriers of explosively driven dense plasmas.

A high explosive shock tube of non-ideal gaseous plasma for proton radiography is described. The gas dynamic flow in the shock compressed xenon at initial pressure of 7 bar was investigated in the tube. The velocity of the shock wave in xenon and the associated particle velocity were measured by a high-speed rotating mirror streak camera. Experimental time-distance data was used for approximation of the velocities by exponential decay functions. The shock tube is intended for generation of non-ideal plasma of xenon at the pressure of 5-12 kbar, the density of 0.24-0.3 g/cm(3) when the initial pressure is about 7 bar.