These cross sections were measured by the process of passing a deuteron beam into a thin gas target contained behind a thin window of evaporated silicon monoxide. The energy loss in the window was measured by a deceleration technique. Charged particles from the reactions were observed at 90° in the laboratory system with proportional counters. Some results are as follows: for the reaction $\mathrm{D}(d, p)\mathrm{T}$, by use of the angular distribution reported by Wenzel and Whaling, the total cross section $\sigma$ is 15.4 mb with a probable error of 3.2 percent at 100-kev incident deuteron energy; $\sigma =0.629\mathrm{} \mathrm{mb}\pm 5$ percent at 25 kev. For the reaction $\mathrm{D}(d, n){\mathrm{He}}^3$, $\sigma =15.2\mathrm{} \mathrm{mb}\pm 3.2$ percent at 100 kev; $\sigma =0.592\mathrm{} \mathrm{mb}\pm 5$ percent at 25 kev. The sum of these two cross sections follows a Gamow function below 50 kev. For the reaction $\mathrm{T}(d, n){\mathrm{He}}^4$, isotropy in the center-of-mass system being assumed, $\sigma$ shows a peak value of 4.95 barns±2.8 percent at 107 kev; at 40 kev, $\sigma =0.72\mathrm{} \mathrm{barn}\pm 3.2$ percent; at 19 kev, $\sigma =0.045\mathrm{} \mathrm{barn}\pm 5$ percent; below 19 kev, $\sigma$ follows a Gamow function. For the reaction ${\mathrm{He}}^3(d, p){\mathrm{He}}^4$ with isotropy assumed, $\sigma =16\mathrm{} \mathrm{mb}\pm 3$ percent at 93 kev; $\sigma =0.124\mathrm{} \mathrm{mb}\pm 5$ percent at 36 kev; and $\sigma$ follows a Gamow relation below 100 kev.

• Received 31 August 1953

DOI:https://doi.org/10.1103/PhysRev.93.483