Surface-coupling to collective modes and nonconventional sources of coherent x-rays

Chapter 1 introduces basic concepts of the Landau theory of normal Fermi liquid. In its framework both the Landau and Landau Silin kinetic equations are derived together with the energy flow theorem and the specular boundary condition. In Chapter 2 the Landau equation, subject to the specular boundary condition, is solved in the collisionless regime for a sample of normal 3He excited by a surface perturbation of arbitrary omega and fixed k. In Chapter 3 a similar technique is proposed for probing the particle-hole and collective excitations in normal 3He via a magnetic surface wave of arbitrary omega and fixed k generated by the meander-line coil. In Chapter 4 the same magnetic perturbation is applied to ferromagnet. Chapter 5 explores the idea of using a superlattice as an undulator for a free electron laser. A purely classical treatment of relativistic positrons channeling through the superlattice performed in a self-consistent fashion is presented. Chapter 6 discusses a possibility of achieving the population inversion in a beam of relativistic hydrogen-like ions by the application of a π-pulse of laser radiation tuned to the Doppler-shifted 1s-2p transition