Neutrons from Deuteron Breakup on D, T, and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="normal">He</mml:mi></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>

Abstract

The continuous neutron spectra produced by deuteron bombardment of D, T, and ${\mathrm{He}}^{4}$ have been studied at deuteron energies near 9 MeV with a time-of-flight spectrometer. Angular distributions of the continuous spectra from D+$d$ and ${\mathrm{He}}^{4}$+$d$ were obtained for deuteron energies of 9 and 10 MeV. The center-of-mass angular distributions are peaked forward for neutrons of all energies. Two maxima present in the 0\ifmmode^\circ\else\textdegree\fi{} spectrum from ${\mathrm{He}}^{4}$+$d$ at ${E}_{d}=10$ MeV are consistent with the interpretation that ${\mathrm{He}}^{5}$ and ${\mathrm{Li}}^{5}$ are produced in their ground states as alternative intermediate steps in the reaction. Two maxima are also present in the continuous neutron spectrum from T+$d$. The higher energy maximum occurs near the maximum possible neutron energy from the $\mathrm{T}(d, np)\mathrm{T}$ reaction and cannot be caused by the $\mathrm{T}(d, 2n){\mathrm{He}}^{3}$ reaction. If this peak is caused by an excited state in ${\mathrm{He}}^{4}$, it would correspond to an excitation in ${\mathrm{He}}^{4}$ of 20.0\ifmmode\pm\else\textpm\fi{}0.2 MeV, and be unbound.