Published online by Cambridge University Press: 24 October 2008
The protons emitted from boron, when it is bombarded by α-particles from radium C′ and polonium, have been examined. All have been ascribed to the disintegration of the B10 isotope following the capture of an α-particle. Four energy changes with values 3·1 m.v., 0·4 m.v., − 0·1 m.v., and − 1·0 m.v. are necessary to explain the range distribution observed. Experiments with α-particles from polonium also show that penetration through the top of the potential barrier stops at an energy of 3·6 m.v. and that below this there is a resonance level at about 2·9 m.v.
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¶ Throughout this paper m.v. will be used to denote million electron volts.
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