560 



BELL SYSTEM TECHNICAL JOURNAL 



t = \Tr I {2^ gixf) \ the first maximum occurs when u = 2r, etc. This 

 fluctuation in resistance is due to the phase shift in the current density 

 as we proceed from the surface of the conductor to deeper layers. 

 The "optimum" resistance is Roiiir/l) tanh irJ2) = 1.44i?o, plus or 



0.8 



0.5 



3|f\J 



z 



10 



+ 



0.2 



-0.3 



-0.8 



5 6 



a 



0.3 



:J|fvi 



:i|w 



=Jh 



d|(M 



•0.8 



Fig. 4 — The ratios of the transfer resistance and transfer reactance of a cylindrical 

 shell to its d-c. resistance. 



minus the curvature correction tllr. If curvature is disregarded, 

 the ratio of the optimum resistance to the resistance of the infinitely 

 thick conductor with the same mternal diameter as the hollow con- 



