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BELL SYSTEM TECHNICAL JOURNAL 



another, successively receives the electrons deflected through tlie 

 various angles. The electrons depart from b\ with very low speeds 

 and receixe the speed U through acceleration by a \oltage ajiplied 

 between Fi and the c\lindcr surrounding F\\ thereafter the>' nio\e 

 with constant spc-cd in an (•(luipolcnlial icninn, lliniugii the \ariiiu> 



Fig. 11 



slits siiown in liie diagram around (', an<I against the target. .Xniong 

 the electrons which emerge from the target, there are some which 

 have been dedectcd !)>■ indixidual atoms in the wa\' we ha\c lnvii 

 describing, but \ery man\' more which li.ivi- liiJicr undergone st-\eral 

 deflccti(jns in succession or else were nm in the incident beam but 

 have l)een dislodged from their places in the target metal by liu- 

 primary electrons. If these latter were allowed to reach the col- 

 lector, the distribution-in-angle funciicm nl the once-dellectcd electrons 

 would be blurred and conceali-d b\ the unwanted electrons. As, 



