Previous measurements on the ${\mathrm{Be}}^9\mathrm{}(d,n)\mathrm{}{\mathrm{B}}^{10}$ neutron spectrum at 0° and 80° have been extended to 10°, 30°, and 45° to check the energy level assignments and to deduce the parity of the levels from a Butler analysis of the angular distributions. The observed neutron groups correspond to levels of ${\mathrm{B}}^{10}$ at 0.72, 1.75, 2.15, 3.53, 4.78, 5.14 (doublet), 5.37 (?), 5.58, 5.72 (?), 5.93, 6.12 (possibly doublet), 6.38, 6.58, and 6.77 Mev. The estimated uncertainty is 0.06 Mev for the first five states of ${\mathrm{B}}^{10}$ and 0.04 Mev for the higher energy levels. The Butler analysis of the angular distribution data indicates that the ground state and the first four excited states of ${\mathrm{B}}^{10}$ are of even parity and that both components of the 5.14-Mev doublet are probably odd parity states. Parity assignments for some of the other energy levels have been attempted. The spins of these states cannot be uniquely determined on the basis of the Butler analysis, but the possible spin limits are listed. A ${\mathrm{Be}}^9\mathrm{}(d,p)\mathrm{}{\mathrm{Be}}^{10}$ exposure was also made. There do not appear to be any states in ${\mathrm{Be}}^{10}$ between the ground state and the known 3.37-Mev level.

• Received 17 June 1952

DOI:https://doi.org/10.1103/PhysRev.88.298