I. V. Puzynin

ASYMPT: a program for calculating asymptotics of hyperspherical potential curves and adiabatic potentials

A FORTRAN program is presented which calculates asymptotics of potential curves and adiabatic potentials with an accuracy of O( 2 ) in the framework of the hyperspherical adiabatic (HSA) approach. Here, is the hyperradius. It is shown that matrix elements of the equivalent operator corresponding to the perturbation 2 have a simple form in the basis of the Coulomb parabolic functions in the body-fixed frame and can be easily computed for high values of total orbital momentum and threshold number. The second-order corrections to the adiabatic curves are obtained as the eigenvalues of the corresponding secular equation. The eigenvectors computed are used to calculate the relevant corrections to matrix elements of potential coupling. The asymptotic potentials obtained can be used for the calculation of the energy levels and radial wave functions of twoelectron systems in the adiabatic and coupled-channel approximations of the HSA approach and also in scattering calculations.

CANM, a program for numerical solution of a system of nonlinear equations using the continuous analog of Newton's method ☆

A FORTRAN program is presented which solves a system of nonlinear simultaneous equations using the continuous analog of Newtons method (CANM). The user has the option of either to provide a subroutine which calculates the Jacobian matrix or allow the program to calculate it by a forward-difference approximation. Five iterative schemes using different algorithms of determining adaptive step size of the CANM process are implemented in the program.

Polaron Model of the Formation of Hydrated Electron States

A computer simulation of the formation of photoexcited electrons in water is performed within the framework of a dynamic model. The obtained results are discussed in comparison with experimental data and theoretical estimates.

Mathematical modeling of the evolution of polaron states

The evolution of polarons in a homogeneous medium is studied depending on model parameters and initial conditions that are chosen in the form of various combinations of stationary polaron states. A computational scheme and results of numerical modeling are presented.

New effective adiabatic approach to the muonic three-body scattering problem

The effective adiabatic approach to analysis of the three-particle interaction is presented. It gives a possibility to represent even in a simple two-level approximation all qualitative peculiarities of mesic atomic resonance reactions and to obtain a good quantitative agreement with different cumbersome calculations.

Simulation of the interaction of nanoclusters with metal films

The interaction of beams of metal clusters with thin metal films as a function of the beam intensity is studied via molecular dynamics simulation. It is discovered that nanopore formation begins with the appearance of hollows in the form of craters and ends with the formation of through holes as the number of impinging nanoclusters increases. The depth of the formed crater depends on the number of impinging nanoclusters and on the interval between nanoclusters in the beam. The phenomenon of the contraction of nanopores formed during the bombardment of a thin metal layer by nanoclusters is revealed.

Numerical study of the phase transitions occurring in metals under the action of pulsed ion beams within the framework of the thermal spike model

Phase transitions occur in materials under the action of high-current high-power beams of charged particles. As a rule, such problems are solved within the framework of the heat-conduction equation. In this paper, studies of phase transitions are carried out within the framework of the thermal spike model, and both models are analyzed and compared. It is established that taking the electron gas into account significantly affects the dynamics of the crystal-lattice temperature and the dynamics of the phase transition.

Fine and hyperfine structure of antiprotonic helium

We consider the fine and hyperfine splitting of the energy levels of antiprotonic helium pHe+ in highly excited rotational states in connection with the interpretation of the recently discovered delayed annihilation of antiprotons in helium, based on the Condo model.

ENERGY LEVEL SCHEME OF PHE+ SYSTEM IN GENERALIZED ADIABATIC APPROACH

The energy level scheme of the states of the ¯pHe+ system is studied in the effective adiabatic approach which has been developed in our previous work. The possibilities for fitting the experimental data by means of an appropriate choice of effective potentials are discussed. Systematic calculations of the energy level system and their estimations are given.

A GENERALIZED ADIABATIC APPROACH TO EXOTIC THREE-BODY SYSTEMS

A generalized adiabatic approach providing the asymptotic separation of the fast and slow variables for the three-body muonic scattering problem is considered. A uniform classification scheme of the different adiabatic bases for some typical three-body Coulomb systems is discussed. The estimations of the cross section of the elastic scattering process (t¯p)n=1+d→(t¯p)n=1+d are presented.