ABSTRACTS OF TECHNICAL ARTICLES 393 



<r = Af(T)exp-(E/2kT). At temperatures between 227°C and a higher 

 temperature of 4(10 500°C a = Aexp—{E/2kT), where £ lies between 0.3 

 and 0.8 ev; and at high temperatures a = Aexp—(E/2kT), where E = 1.12 

 ev. The value 1.12 ev represents the separation of the conducting and 

 non-conducting bands in silicon. The long wave limit of the optical absorp- 

 tion of silicon was found to lie at approximately 10,500 A (1.18 ev). The 

 data lead to the conclusion that the same electron bands are concerned in 

 the photoelectric, optical, and thermal processes and that the low values 

 of specific conductances found (1.8X10~* ohm~^ cm~^) are caused by the 

 high purity of the silicon rather than by its polycrystalline structure. 



Non-Uniform Transmission Lines and Reflection Coefficients}^ L. R. 

 Walker and N. Wax. A first-order differential equation for the voltage 

 reflection coefficient of a non-uniform line is obtained and it is shown how 

 this equation may be used to calculate the resonant wave-lengths of tapered 

 lines. 



^*Jour. Applied Physics, December 1946. 



