Differential cross sections for the $\mathrm{T}(d, n){\mathrm{He}}^4$ reaction have been measured as a function of energy at ${\theta }_n=6\mathrm{}°$ (c.m.) from $E_d=1.0\mathrm{} \mathrm{to} 5.0$ Mev and as a function of angle at $E_d=1.53, 2.21, 3.05, 3.97, 4.98, \mathrm{and} 5.79$ Mev. The estimated uncertainties are within the range ±8% to ±11%. Although no sharp anomaly appears in the 6° excitation curve, there is a slow increase of ∼50% from 2.5 to 5 Mev. In this energy region the total cross section is flat or, perhaps, even slightly rising with increasing energy; whereas below 2.5 Mev it is a sharply decreasing function of energy. When compared with the much lower cross section reported at $E_d=10.5\mathrm{}$ Mev, the present data may indicate a new level of ${\mathrm{He}}^5$ with an excitation of ∼22 Mev. The angular distributions, however, do not lend direct support to the resonance assumption since they are asymmetrical and contain large forward peaks.

• Received 25 June 1956

DOI:https://doi.org/10.1103/PhysRev.104.421