Nuclear Energy Levels inB10

Five thousand stereoscopic pictures of electron tracks in a cloud chamber yielded six hundred sixty-five Compton electrons from a thin mica foil and seventy-six ± electron pairs formed in the gas in the chamber. These data indicate thirty-one lines in the $\gamma$-ray spectrum of ${\mathrm{B}}^{10}$. Nine energy levels account for the observed lines in a satisfactory manner, and are not in disagreement with the neutron spectrum from the same reaction. An attempt to correlate the observed energy levels with those predicted by theory leads to the following suggested classification: ${}_{}{}^3{}_{}{}^{}S_1^{}{}_{}{}^{}$ as the ground state (relative energy zero); ${}_{}{}^3{}_{}{}^{}D_{123}^{}{}_{}{}^{}$ at 0.26, 0.50 and 0.61 Mev; ${}_{}{}^1{}_{}{}^{}S$ at 1.44 Mev; ${}_{}{}^1{}_{}{}^{}D$ at 1.93 Mev; ${}_{}{}^3{}_{}{}^{}D$ at 2.92 Mev; and ${}_{}{}^1{}_{}{}^{}D$ at 3.64 Mev; and ${}_{}{}^3{}_{}{}^{}F$ at 4.73 Mev.