﻿282 Mr. R. D. Kleeman on the Recombination 



constant and r the maximum range of an uranium a particle 

 in air. The total ionization in the cylinder for a length r x 

 measured from the uranium becoming consequently 



(.,-¥) 



tJ k - 



The ionization I in terms of the saturation current between 

 the plate on which the uranium oxide is spread and a plane 

 at a distance x, is then given by 



1 = ^ \lrdO . 27rrsin B + Kn^ rd0.2^rsm O^v + ^ ). 



where - =cos 6u — =cos 0, and n denotes a constant, and 6 



r r x 



the angle the projected particle makes with %, Integrating 

 this equation we obtain 



I = \Kn7rr 2 < x 2 — 2rx 1 og — 5- . 



Curve A in fig. 3, taken from one of Langevin's papers, 



Fiff. 3. 

















































































H 











HT 







- — ■? 



*■ — 



























































Py 











/ 



E 



































/ 



<d 





































































/ 



/ 



f C 



'B 



































/] 



/a 







Or 



] Q 































\\ 









<0 



i 































f 









































r, 



on 



2 



TAN. 

 2 



4 



5 



Vglts P£R 



shows the relation between current and distance of a plane 

 from a lead plate when the intervening space is ionized by 

 the secondary X rays produced by primary rays falling on 

 the lead plate, the abscissae denoting distances from the lead 

 plate and the ordinates the corresponding currents. 



If the ordinate 8*3, corresponding to the distance *5 cm. 



