GUIDED WAVE PUOPAGATION THHOUGH GYUOMAGNETIC MEDIA. 11 U(i 1 

 3. CYLINDRICAL GEOMETRY 



3.1. Impedances 



In this section we consider systems witli cylindrical symmetry about 

 the propagation (Urection. All boundaries, those of the circuit as those 

 of the medium, are coaxial circular cylinders, and the medium is as- 

 sumed to be magnetized circumferentially. The practical means for 

 bringing about such a magnetization — for example, thin wires threaded 

 through a C3'linder of ferrite and carrying a dc current, Fig. 1 (b) — are 

 assumed to effect the electromagnetic field to a negligible extent. As 

 in the case of planar geometry, we restrict ourselves to fields which have 

 no \-ariation along the magnetizing field; that is, in the azimuthal direc- 

 tion. Only the ferrite is considered here; the results for a plasma are 

 obvious corollaries. The magnetizing field and the dc magnetization 



FORWARD WAVE 



VARIATION IN PHASE 



AND LOSS OF FORWARD 



WAVE IS SMALL 



-0.6 



RJZ,Z 



Fig. 7 — Real and imaginary parts of /3+ and /3_ for a flat helix at the veiy .small 

 magnetizing field recjuired to saturate the ferrite. 



