Energy Exchange between an Electron Beam and a Gap in the Presence of Collisions†

The energy exchange between an electron beam and a gap in the presence of collisions is treated by means of a one-dimensional theory. The aim of the calculation i9 to discover the effect of collisions on the negative conductance known to occur for a certain range of gap lengths in the absence of collisions. A collision term is introduced phenomenologically into the equation of motion for the electrons and the small signal power theorem is also modified to take account of collisions. It is found that the effect of collisions is surprisingly small, a negative gap conductance still being obtained for collision frequencies as high as the plasma frequency.     

Structure of the Energy Spectrum of Holes in IV–VI Materials from a Different Viewpoint

Semiconductors - A twofold decrease in the hole concentration for all PbTe〈NaTe〉 samples at 77–450 K and the same effect attained at 77 K and upon heavy doping due only to the...     

Synthesis of Current–Voltage Characteristics of 670 GHz Gyrotron Magnetron Injection Gun and Calculation of the Helical Electron Beam Parameters at the Leading Edge of a High-Voltage Pulse

A method of synthesis of current–voltage characteristics (CVC) and calculation of the parameters of a helical electron beam (HEB) at the leading edge of the accelerating voltage pulse for gyrotron electron guns is proposed. These data can be used for a study of the gyrotron startup scenario with the mode competition taken into account. As an example, the results of calculations for a pulsed gyrotron with a frequency of 670 GHz are presented.     

Sharp Drop in the Mobility of Holes with a Decrease in Their Two-Dimensional Concentration by an External Voltage in Boron δ-Doped Diamond Layers

Semiconductors - It is shown, both analytically and numerically, that the hole mobility in boron δ-doped (i.e., with a thickness on the order of several lattice constants) diamond layers drops...     

Simulation of the β-voltaic effect in silicon pin structures irradiated with electrons from a nickel-63 β source

The prospects of β voltaics as electric-power sources for semiconductor circuits are considered. Experimental studies show that charging of the surface and a decrease in the electrovoltaic power are important. Simulation of the β-voltaic effect induced by electrons from a nickel-63 source on silicon pin structures is performed; it is shown that the coefficient of the collection of generated charge carriers can be as high as 13%. The dose dependences of the performance efficiency of silicon β-voltaic structures are determined for the case of irradiation with α particles and γ-ray photons; it is shown that 1.3 × 10¹⁴ and 10²⁰ cm^–2, respectively, are the threshold doses, above which a rapid decrease in efficiency occurs. The optimal parameters of microchannel structures in β-voltaic electronics, in which the width of the channels and the distance between them correspond to 3 and 10 μm, are determined.