Internal Pair Spectrum fromB10+d

A magnetic lens pair spectrometer has been used to measure the energy spectrum of the internal pairs formed from the bombardment of ${\mathrm{B}}^{10}$ with deuterons. The spectrometer has been calibrated with the nuclear pair from ${\mathrm{F}}^{19}+p$ with an energy of 6.05±0.03 Mev. The ${\mathrm{B}}^{10}$ spectrum shows gamma-rays of energies 4.43±0.07, 6.51±0.13, 6.75±0.13, 7.34±0.20, and 8.93±0.13 Mev. Unresolved lines appear to exist in the region 4.5 to 5.5 Mev. The 6.51 Mev line is tentatively assigned to ${\mathrm{C}}^{11*}$ while the other lines can be attributed to ${\mathrm{B}}^{11*}$.