Simulation of an experiment on detecting ultra-high-energy particles with regard to the structure of the lunar soil surface layer

The feasibility of using the lunar orbital radio detector to detect radio signals from cascades initiated by ultra-high-energy cosmic rays interacting with the lunar regolith is studied. Simulation by the Monte Carlo method demonstrates that, with the regolith thickness randomly distributed in the range 2–12 m, the detection of radio signals reflected from the lower boundary of the regolith (for particle energies W ≥ 10²⁰ eV) increases the number of valid events severalfold. The additional contribution due to the reflected radio-frequency radiation greatly enhances the scientific potential of experiments with the lunar orbital radio detector.     

Solitary surface acoustic waves and bulk solitons in nanosecond and picosecond laser ultrasonics

Recent achievements of nonlinear acoustics concerning the realization of solitons and solitary waves in crystals and their surfaces attained by nanosecond and picosecond laser ultrasonics are discussed and compared. The corresponding pump-probe setups are described, which allow an all-optical contact-free excitation and detection of short strain pulses in the broad frequency range between 10 MHz and about 300 GHz. The formation of solitons in the propagating longitudinal strain pulses is investigated for nonlinear media with intrinsic lattice-based dispersion. The excitation of solitary surface acoustic waves is realized by a geometric film-based dispersion effect. Future developments and potential applications of nonlinear nanosecond and picosecond ultrasonics are discussed.     

Working group report: Heavy-ion physics and quark-gluon plasma

This is the report of Heavy Ion Physics and Quark-Gluon Plasma at WHEPP-09 which was part of Working Group-4. Discussion and work on some aspects of quark-gluon plasma believed to have created in heavy-ion collisions and in early Universe are reported.     

Numerical study of shock compression of graphite and its conversion to diamond in conical targets

The shock compression of carbon placed into lead conical targets that are subjected to a blow from aluminum strikers moving at a velocity of 4 km/s is numerically studied. The statement of the problem includes the hydrodynamic equations for compressed media, semi-empirical wide-range equations of state, and a kinetic model of nonequilibrium graphite-to-diamond conversion that is calibrated with known experimental data. All stages of the process are analyzed, starting from the cumulative effect at the symmetry axis of the target to the release of the sample due to the rarefaction wave coming from the rear side of the striker with allowance for spalling.     

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.     

Solid-phase fluorometric determination of Al(III), Be(II), and Ga(III) using dynamic preconcentration on reagent cellulose matrix

A fluorimeter is developed, which provides sample pretreatment, preconcentration of analytes from natural waters on the surface of indicator cellulose matrices, and the simultaneous measurement of their fluorescence. The device employs a L-711UVC ultraviolet light diode and a Digital color sensor S9706 photodiode, which registers simultaneously in the red (615 nm), green (540 nm), and blue (465 nm) spectrum regions. The opportunities of the application of this fluorimeter have been shown by an example of determination of 1–100 μg/L Al(III) and 0.1–10 μg/L Be(II) and Ga(III).