Modification planning in technical systems

Translated from Vychislitel'nye Kompleksy i Modelirovanie Slozhnykh Sistem, pp. 55–70, Moscow State University, 1989.     

Stimulated scattering of electrons by photons and adiabatic switching on hypothesis

The stimulated scattering of electrons by a standing light wave is considered. The amplitude of the standing wave is supposed to be slowly switched on and slowly switched off after the interaction. It is found that the scattering probability can be small due to the slowness of the switching-on process. The Kapitza-Dirac effect disappears in the adiabatic limit. The resonance scattering is considered which arises when another (running) light wave is added. The corresponding probability and the scattering directions have been derived.     

New phases with fluorite-derived structure in CaF2(Y,Ln)F3 systems

Crystallographic characteristics of six new phases of idealized composition Ca₈R₅F₃₁ which are formed in the CaF₂RF₃ (R = Y, HoLu) systems are reported. All the phases have a similar structure derived from CaF₂ with slight distortion and pseudocubic unit cell parameters a_ord = 13a_dis (where a_dis is the parameter of the fluorite subcell). The degree of ordering increases in the lanthanide series with decrease of ionic radius and, in every system given, with an increase in the RF₃ content of the solid solution. Significant influence of temperature and time of annealing on the degree of ordering was not detected.