920 Mr. F. P. Slater on Excitation of y Radiation 



In fig. 6 the logarithm of the ionization is plotted against 

 the thickness in mms. o£ absorbing aluminium for the soft 



Fiar. 6. 



L °g 



1-50 



O-50 



'on 





© © © 



Goto, 





( 





9 © © 



XXX 



P/9ttOU/7> 









\0- 













\ 







020 040 0-60 0-80 1-00 



M/ns. o-P A/um/o/'am. 



Fig. 7. 



Log 



type from Pb, Au, and Pt respectively. Similarly, fig. 7 

 shows the Log I-thickness curves for the hard radiations 

 from the same elements. 



