[POUND] ABSORPTION OF THE DIFFERENT TYPES OF BETA RAYS 7 7 



TABLE XIII. 



Remarks. 



Saturation current. 



mm. mm. mm. mm. mm. mm. mm 



Thickness of aluminium over 

 the top of chamber 



I 

 Max. P + P secondary + 

 7+7 secondary + nat- 

 ural ionisation.. 



II 



y + X secondary + natural 

 ionisation 



Ill 



Max. (i-\-p secondary ioni 



sation 



IV 



0.0 



365 



12.6 



352.4 

 352.4 



.0065 



396.5 



10.2 



386.3 

 386.3 



.28 



287.5 



11. 



276.5 

 276.5 



1.184 



79.3 



12.3 



67.0 

 67.0 



3.41 



20.3 



13.1 



7.2 

 6.7 



4.73 



13.5 

 12.3 



1.2 



.7 



8.14 



12.2 



11.7 



.5 

 .0 



TABLE XIV. 

 Ionisation by /3 reflected secondary rays from aluminium. 



