This volume contains two papers that review certain theoretical problems that have been studied in the Laboratory of Plasma Accelerators and Plasma Physics of the P. N. Lebedev Physics Institute of the Academy of Sciences of the USSR. The review of R. R. Kikvidze and A. A. Rukhadze, "Theory of oscillations and stability of a semiconductor plasma with low carrier density in a strong electric field," is devoted to a solid-state plasma. The main attention is devoted to the fact that in such a plasma electro- magnetic waves are effectively generated if there is a negative current-voltage...

It is well known that luminescence is the term used to describe the excess radiation from a body over and above the thermal radiation and persisting for a time which greatly exceeds the period of a light vibration. The first half of this definition, proposed by Wiedemann, distinguishes luminescence from equilibrium thermal radi ation; the second half, introduced by Vavilov, distinguishes luminescence from various forms of scattering and from induced radiation, such as Vavilov-Cherenkov radiation, etc. Distinctions are made between photo-, cathodo-, x-ray-, and other forms ofluminescence,...

The first part of this collection sets out the results of some experimental and theoretical investigations into the optical properties of nontransition metals. The extensive future pros- pects of metal optics are indicated; the use of metal optics enables a whole series of import- ant electron properties of metals to be determined. Results obtained by studying intermolecular forces (the hydrogen bond and van der Waals forces) using spectroscopic methods (Raman effect and infrared absorption) are presented in the second part. A method of studying the true absorption of the drop phase of a...