V.I. Vysotskii

Formation and application of correlated states in nonstationary systems at low energies of interacting particles

We consider prerequisites and investigate some optimal methods for the formation of a correlated coherent state of interacting particles in nonstationary systems. We study the influence of the degree of particle correlation on the probability of their passage through the Coulomb barrier for the realization of nuclear reactions at low energies. For such processes, the tunneling probability and, accordingly, the probability of nuclear reactions can grow by many orders of magnitude (in particular, the barrier transparency increases from Dr = 0 ≈ 10−42 for an uncorrelated state to D|r| = 0.98 ≈ 0.1 at a correlation coefficient |r| ≈ 0.98). The formation of a correlated particle state is considered in detail for different types of monotonic decrease in the frequency of a harmonic oscillator with the particle located in its parabolic field. For the first time, we have considered the peculiarities and investigated the efficiency of the creation of a correlated state under a periodic action on a harmonic oscillator. This method is shown to lead to rapid formation of a strongly correlated particle state that provides an almost complete clearing of the potential barrier even for a narrow range of oscillator frequency variations.

Subbarrier interaction of channeling particles under the self-similar excitation of correlated states in a periodically deformed crystal

It has been shown that application of the periodic modulation of parabolic potential well parameters (in the case of charged particle channeling in crystals, i.e., periodic spatial modulation of the wall height of a potential well in the crystal channel) leads to the formation of the coherent channeling state in particles in this well. The formation of this state changes the interaction process between these particles and nuclei, and increases the barrier transparency by many times. For channeling this mode can be formed using, e.g., the longitudinal acoustic wave running along the channel axis. This wave changes the distance between nuclei and, accordingly, modulates the height of channel walls.

The formation of correlated states and the increase in barrier transparency at a low particle energy in nonstationary systems with damping and fluctuations

We consider peculiarities in the formation of a coherent correlated state (CCS) of a particle in a periodically modulated harmonic oscillator with damping for various types of stochastic perturbation. It is shown that in the absence of stochastic perturbation, an optimal relation exists between the damping parameter (damping coefficient) and the modulation depth, for which the “extrinsic” characteristics of the oscillator (amplitudes of “classical” oscillation and the momentum of a particle) remain unchanged, while the correlation coefficient rapidly increases from |r| = 0 to |r|max ≈ 1; this corresponds to a completely correlated coherent state. Under nonoptimal conditions, the formation of the CCS with a simultaneous increase in is accompanied by damping or excitation of the oscillator. It is shown that for a certain relation between the damping coefficient and the modulation depth, the presence of a stochastic external force acting on the nonstationary oscillator does not prevent the formation of a CCS with |r|max → 1. A fundamentally different effect is observed under a stochastic influence on the nonstationary frequency of the oscillator; this effect always limits the value of |r| at a level |r|max < 1; a CCR cannot be formed with an unlimited increase in its intensity, and |r|max → 0. The influence of the CCS formation on the averaged probability 〈D〉 of the tunnel effect (transparency of the potential barrier) is considered for a particle in an oscillator with damping both in the absence and in the presence of a stochastic force. It is shown using a specific example that complete clearing of the potential barrier and the increase in the barrier transparency from the initial value 〈Dr=0〉 = 10−80 to 〈D〉 ≈ 1 can occur over a comparatively short time interval in both these cases. These effects can be used to obtain highly efficient nuclear fusion at a low energy of interacting particles.

Correlated states and transparency of a barrier for low-energy particles at monotonic deformation of a potential well with dissipation and a stochastic force

The features of the formation of correlated coherent states of a particle in a parabolic potential well at its monotonic deformation (expansion or compression) in finite limits have been considered in the presence of dissipation and a stochastic force. It has been shown that, in both deformation regimes, a correlated coherent state is rapidly formed with a large correlation coefficient |r| → 1, which corresponds at a low energy of the particle to a very significant (by a factor of 1050–10100 or larger) increase in the transparency of the potential barrier at its interaction with atoms (nuclei) forming the “walls” of the potential well or other atoms located in the same well. The efficiency of the formation of correlated coherent states, as well as |r|, increases with an increase in the deformation interval and with a decrease in the deformation time. The presence of the stochastic force acting on the particle can significantly reduce the maximum |r| value and result in the fast relaxation of correlated coherent states with |r| → 0. The effect of dissipation in real systems is weaker than the action of the stochastic force. It has been shown that the formation of correlated coherent states at the fast expansion of the well can underlie the mechanism of nuclear reactions at a low energy, e.g., in microcracks developing in the bulk of metal hydrides loaded with hydrogen or deuterium, as well as in a low-pressure plasma in a variable magnetic field in which the motion of ions is similar to a harmonic oscillator with a variable frequency.

Generation of X-Rays at Bubble Cavitation in a Fast Liquid Jet in Dielectric Channels

The paper presents the results of studying the combined shock-wave radiation-emission processes associated with cavitation phenomena that occur at fast directional motion of a liquid jet into a closed working chamber through narrow dielectric channels. These processes induce high-power tunable X-ray radiation outside the chamber. At a relatively small liquid pressure, cavitation has been shown to generate shock waves in the chamber walls, which excites surface atoms and leads to the emission of X-rays from the outer surface of the chamber. At a high liquid pressure, the liquid jet does not touch the chamber walls and the cavitational shock waves lead to the excitation of the surface atoms of the jet itself accompanied by the generation of optical and X-ray radiation in the jet, which has been also observed in experiments.

Generation of intense x-rays during ejection of a fast water jet from a metal channel to atmosphere

The radiation processes associated with a supersonic water jet exhausting from a narrow channel are considered. It has been found for the first time that the output of the channel and the initial portion of the jet are sources of intense X-radiation, generation of which is related to cavitation processes in the water jet bulk and subsequent excitation of shock waves. The frequency of X-radiation depends on the types of atoms on a radiating surface (for a jet, it is water; for a channel, the metal atoms on the surface) and increases with the charge of atoms. The total X-ray activity of an experimental setup in the mode of jet exhaust reaches 0.1 Ci. It is found for the first time that the impact of shock acoustic waves, which are formed in the air as a result of cavitation jets of water, on distant screens leads to the generation of a quasi-coherent directional X-ray emission from the back side of these screens. The spatial parameters of this radiation depend on the shape and cross section of the screen and the spatial characteristics of the shock wave.

Generation of intense directional radiation during the fast motion of a liquid jet through a narrow dielectric channel

The results of theoretical and experimental studies of the cavitation phenomena in the volume of a moving liquid jet after its passing through thin and long oriented channels in dielectrics are considered. It is shown that the stationary generation of intense directional radiation in the optical range occurs in the moving jet volume as a threshold pressure is reached in the liquid (pure spindle oil). The parameters of radiation are close to those of laser radiation. The effective temperature of the generation region was estimated as corresponding to 50–100 eV. In some cases, optical radiation is accompanied by the pulsed generation of directional gamma radiation. These processes are accompanied by a sequence of high-voltage electric discharges of a great length in the liquid bulk and at the surface, corresponding to potential differences of 50–100 kV. One of the causes of the observed phenomena can be energetically favorable nuclear fusion reactions involving light nuclei in the liquid jet volume. It was shown that such processes can be efficiently stimulated by multibubble cavitation.

Formation of correlated states and optimization of nuclear reactions for low-energy particles at nonresonant low-frequency modulation of a potential well

A method for the formation of correlated coherent states of low-energy particles in a parabolic potential well owing to the full-scale low-frequency modulation ω(t) = ω0sinΩt of the parameters of this well has been considered. It has been shown that such a modulation in the absence of a stochastic force acting on a particle results in the fast formation of correlated coherent states and in an increase in the correlation coefficient and transparency of the potential barrier to the limiting values |r(t)|max → 1 and D → 1. The presence of the stochastic force significantly affects the evolution of correlated coherent states, decreasing the rate of an increase in the correlation coefficient |r(t)|max (at Ω ≤ 10−4ω0) and limiting it at the level |r(∞)|max < 1 (at Ω = (0.001–0.1)ω0); |r(∞)|max increases with a decrease in the frequency of modulation and decreases with an increase in the intensity of the stochastic force. It has been shown that, at a realistic relation between the parameters, low-frequency modulation can ensure such |r|max value that the transparency of the potential barrier for low-energy particles increases by a factor of 1050–10100 or larger. The mechanism of the formation of correlated coherent states for charged particles in a gas or a low-pressure plasma placed in a low-frequency magnetic field has been considered. We have determined the relation between the magnetic field strength and modulation frequency, as well as the relation between the temperature and density of the gas (plasma), at which the method under consideration can be used to optimize nuclear reactions at low energies.

The formation of correlated states and optimization of the tunnel effect for low-energy particles under nonmonochromatic and pulsed action on a potential barrier

We consider peculiarities of the formation of a coherent correlated state (CCS) of a low-energy particle under frequency modulation of parameters of a harmonic oscillator that contains this particle by a broadband nonmonochromatic or asymmetric pulsed action. It is shown that in the case of modulation with frequency-normalized intensity, the maximum efficiency of CCS formation corresponds to a narrow-band action, while broadband modulation is optimal for the action with a constant spectral density. As in the case of monochromatic modulation, the maximum correlation coefficient, |r|max, under the nonmonochromatic action corresponds to parametric resonance at frequency Ω ≈ 2ω0. Under a pulsed action, the maximum efficiency of CCS formation and, hence, the maximum probability of the tunnel effect, correspond to pulsed modulation with a short leading edge and a long trailing edge. In particular, under the action of a pulsed magnetic field with an amplitude of 10 kOe and the leading edge duration of 2 × 10–7 s on a gas with deuterium ions, a CCS can be formed with the correlation coefficient |r|max ≈ 0.9998, for which the tunneling effect probability under the dd interaction at temperature T ≈ 300–500 K increases from Dr = 0 ≈ 10−80 to