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BELL SYSTEM TECHNICAL JOURNAL 



next above it, one adds the effect of slower alpha-particles; whereas in 

 Fig. 6, in going from one curve to the next above it, one adds the effect 

 of faster projectiles. 



The contrast between the lowest and the next-to-lowest curve of Fig. 

 7 is indeed amazing. So long as the impinging corpuscles are moving 



55 



45 



2 35 



< 30 



25 30 35 40 45 50 



AIR-EQUIVALENT IN CENTIMETERS 



Pig^ 7 — More integral distribution-in-range cur\^es for protons emitted from dis- 

 rupted nuclei of aluminium atoms (H. Pose). 



so fast that they still have 3.57 cm. of their range ahead of them, 

 the protons which they eject are comparatively slow, with a maximum 

 range of 30 or thereabouts; but when they are slowed down to some 

 critical speed corresponding to some range between 3.57 and 3.1, they 

 acquire the power of dislodging extremely fast protons. Here we have, in 

 fact, another "group " in the sense of the previous pages: protons which 



