ABSTRACTS OF TECHNICAL ARTICLES 203 



Some Antecedents of Quality Control. E. C. Molina''. Ind. Quality 

 Control, 8, pp. 10-11, July, 1051. 



Traveling-Wave Amplifier Measurements. F. E. Radcliffe^ Electronics, 

 24, pp. 110-111, Aug., 1951. 



Rapid sweep-frequency technique used at 4,000 mc can he applied to all 

 broad-band amplifier measurements. Oscilloscope display shows transmission 

 accurate to 0.1 db and return-loss values up to 40 db. 



Kirchhoff's Formula, its Vector Analogue, and Other Field Equivalence 

 Theorems.* S. A. Sciielkunoff^ Communications on Pure and Applied 

 Math., 4, pp. 43-59, June, 1951. 



Remarks Concerning Wave Propagation in Stratified Media.* S. A. 

 Schelkunoff^ Communications on Pure and Applied Math., 4, pp. 

 117-128, June, 1951. 



An Achromatic Doublet of Silicon and Germanium .* R. G. Treuting^ 

 J . Opt. Soc. Am., 41, pp. 454-450, July, 1951. 



The semi-metals germanium and silicon have high transparency and high 

 refractive indices over a wide range of infrared wavelengths and are stable to 

 normal atmospheres. Their relative indices and dispersions make achromatic 

 combinations possible; and designs are given for axially corrected doublets of 

 relative apertures f:2 and f:l. The optical homogeneity of the materials is dis- 

 cussed : compositional variations are not considered an optical hazard, but there 

 is evidence of structural imperfections in some specimens whose effect on optical 

 properties remains to be evaluated. 



On the Motion of Gaseous Ions in a Strong Electric Field. I.* G. H. 

 Wanxier^ Phys. Rev., 83, pp. 281-289, July 15, 1951. 



This paper applies the Boltzmann method of gaseous kinetics to the prob- 

 lem of positive ions moving through a gas under the influence of a static, uni- 

 form electric field. The ion density is assumed to be vanishingly low, but the 

 field is taken to be strong; that is, the energy which it imparts to the ions is 

 not assumed negligible in comparison to thermal energy. Attention is focused 

 upon the computation of velocity averages, and the drift velocity in particular, 

 rather than a complete knowledge of the entire velocity distribution. It is shown 

 in Sections C and E that the problem so formulated is completely soluble if 

 the mean free time between collisions of ions and molecules is a constant; this 

 is the case for the so-called polarization force between ions and molecules which 

 predominates over other forces at low temperature. A method for obtaining 

 averages to any desired accuracy in the general case is developed in Section D. 

 The method is applied to the hard sphere model for the high field range and 



* A reprint of this article may be obtained on request. 

 1 Bell Tel. Labs. 



* Bell Tel. Labs,, Retired. 



