Indiall J ourn.1 of Radio &: Space .,hysics Vol. 4, June 1975, pp.-124-127 Characteristics of Waveguide Filled with Homogeneous, Warm, Drifting, Anisotropic & Lossy Plasma DINESH SINGH, G. N. TIWARI & S. K. TOLPADI Department ('f Physics, Banaras Hindu University, Varanasi 221005 Received 16 December 1974; revised received 29 March 1975 The dispersion charaCteri~l:cs of TM mode of propagation of electromagnetic wave in homogeneous, warm, drifting and lossy plasma i:1 rcctal1gl1ar waveguide under the influence of strong longitudinal external magnetic field are investigated. The slow, as well as fast space charge waves with no cut·off and perturbed waveguide mode, yield only one mode of rropagation. The attenuation caused by collisions between electrons and net..fals is evalt:atcd over a wide Iange of the frequency spectrum, assuming no absorption of the electromagnetic waves by waveguide walls. V. p.o H = 0 where p.o, fo are the magnetic and electric permittivity for free space and E, the permittivity tensor for the plasma under consideration inside the waveguide. The the existence of three modes 0 f propagation, i. e. slow and fast space-charge waves and a perturbed TM waveguide modes. In this paper, the presence of attenuation and phase constants in uniaxial aniso- tropic compressible drifting plasma waveguide are predicted taking into account the interactions bet- ween electrons and neutrals, and assuming that the value of signal frequency wand the plasma frequency Wp are very sma)) in comparison with the gyro-fre- quency Wb. 2. Basic Equations A rectangular wavrguide consisting of perfect conducting walls of dimension 1 and b is assumed to be completely filled with a collisional, warm, non- relativistic, driftjng plasma. Plasma is assumed to be a single fluid medium in which electrons are taking part in the phenomena of interest and are neutralized by ions on the average. The neutral molecule density is assumed to be such that these molecules constitute a continuous lossy medium. The motion of heavy ions is neglected because of their heavy mass and the collisions of electrons with neutrals are taken care of by the collision frequency which is assumed inde- pendent of electron speed. The field vectors inside the waveguide with ei *'/ time dependence satisfy the following Maxwell's equations: ... (1) V. ~o!:E = 0 V X E =- jwp.oH V X H = jw~o ~: E 1. Introduction THE INTEREST in bounded plasmas started since Tonks and Langmuir discovered high frequency elec- trOn oscillation Jin 1929. These oscillativns have subsequently been investigated in considerable detail by Tonks and Langmuir1, Bohm and Gross2, Van Kampen3 and others. The closely related problem of space charge waves in electron beams have been studied by Hahnt, Ram05, Birdsall and Whinnery6; Trivelpiece and Gould7, Bevc and Everhart8 and Trivelpiece9• Most of the analyses of waves in electron beams and plasma in the presence of external magne- tic fields were devoted mainly to the various modes of propagation. A general solution for propagating modes in waveguides completely or partially filled with plasma, taking into account an applied static magnetic field, non-uniform density over guide cross- section and non-vanishing temperature has not yet been developed. Only certain simplified cases have been analyzed in Iliterature. The propagation charac- teristics of the EM waves in a waveguide filled with cold, &tationary and homogeneous plasma are dis- cussed in considerable detail by Allis et al.lo• Effect of strong longitudinal and transverse magnetic fields on the propagation characteristics of waveguide con- taining cold pbsma has been discussed by Allis et a[1o in term of (w-~) diagrams. They further indicated broad features of the characteristics of the waveguides with inhomogeneous and anisotropic cold plasma. The propagation characteristics of waveguides containing warm and stationary plasma in the pre- ' sence of static magnetic field have been investigated by Samaddarll , Sancer12 and Tuan13• Kalluri14 and Singh15 studied the dispersion characteristics of elec- tromagnetic waves propagating through waveguide containing warm, drifting plasma under the influence of strong longitudinal magnetic field. They showed 124