1210 THE BELL SYSTEM TECHNICAL JOURNAL, OCTOBER 1951 



Solutions based on 5C's having a single source singularity (such as the ex- 

 ample above) will contain four mathematical parameters, and hence will 

 permit arbitrary selection (subject to (6)) of the physical parameters, Ip , 

 /„,(?«,, and "Uoo • However, solutions based on 5C's having more than one 

 source singularity will provide only a subset of the possible assignments of 

 the physical parameters. For example, the harmonic function associated 

 with the electrostatic field produced by two separate point charges each equi- 

 distant from two parallel infinite plane conductors provides solutions of 



\ ! / / 



\ i / / 





Fig. 3— Point source flow field, useful in connection with point contact theory 



Fig. 4 — Two source flow field between conducting planes, useful in connection with 

 Type A transistor theory. 



interest in connection with the type A transistor configuration (Fig. 4). 

 However, the family of solutions obtained contains only a five-parameter 

 subset of the six-parameter family obtainable by arbitrary assignment of 



I pi , I pi , In\ , /n2 , (Pee , and V^ . 



S. Sample Application of the Results of Section M: Spherical 

 Symmetry, A^ = 



We now round out the considerations of Section R by exhibiting the 

 related solutions for AT = (i.e., the intrinsic semiconductor). 



