Interaction of 19-Mev Deuterons with Oxygen

Abstract

The charged particles emitted when oxygen is bombarded with 19-Mev deuterons have been studied by a photographic plate method. The angular distributions of the two groups of protons from the reaction 0 16 (d,p)0 17 , O 17 being formed in the ground and 0.88-Mev states, have been found to be in qualitative agreement with the predictions of the stripping theory. Similar measurements have been made for the elastically scattered deuterons and for the a particles from the reaction 0 16 (d,a)N u ; the curve for the latter shows peaks at about 40°, 90°, and 140°, and is nearly symmetrical about 90°. emulsion at either surface, and by the use of a Faraday cup which gives absolute values of the integrated beam current.The angular distributions of protons emitted in the reaction O u (d,p)0 17 , O 17 being formed in the ground and 0.88-Mev excited states, are shown in Fig. 1, together with curves based on Butler's stripping theory. 2 According to this theory the angular distribution of protons from a (d,p) reaction depends characteristically on the angular momentum, /, transferred by the neutron to the nucleus which it enters. For the two groups observed, / must be 2 and 0 since the O 17 levels have spin and parity 5/2+ and §+, respectively. 3 -4 It will be seen that there is qualitative agreement between the curves expected for these values of / and the experimental points; the agreement is not close, being in fact slightly worse than that observed at 8 Mev, 2,4 but indicates that the theory is correct in principle if not in detail at an energy of 19 Mev. The theory successfully predicts the observed differences in angle of corresponding peaks at 8 Mev and 19 Mev. We are much indebted to Mr. W. M. Fairbairn for calculating the theoretical curves.The total cross sections for the formation of the ground and 0.88-Mev levels of O 17 have been calculated from the angular distributions; the contributions from very small and very large angles, at which measurements were impossible, were estimated with the aid of the theoretical curves. The values obtained are 35.5 ±3.5 and 22.7±3.5 millibarns respectively, while those obtained at 8 Mev 4 were 125=1=9 and 112=1=11 millibarns. Figure 2 shows the angular distribution of deuterons elastically scattered by oxygen, with the Rutherford scattering curve for comparison. Although we cannot be sure of our absolute cross sections to within less than about 8 percent 5 there is no doubt that the cross 2 S.

Elastic Scattering of Deuterons by Heavy Nuclei

“…The details are shown in Figs. [2][3][4][5][6]. * Moreover, the relations between the absorption coefficients and the distance from the nucleus were shown in Fig.…”

The scattering of deuterons and protons by alpha-particles

“…Received August 20, 1954] EARLIER papers have described the use of a scattering cameca i,~ experiments with beams of 19 ~mv deuterons, and of 9.5 sTev protons accelerated as molecular hydrogen, from the 60-in. Birmingham cyclotron (Freemantle, Gibson, Prowse andRotblat 1953, Burcham, (libsou, Hossain and. The camera, which is essentially the same as that described by Burrows, Powell and Rotblat (1951) measurement of differential cross sections from 15 ° to 165 ° for various types of nuclear process in gaseous targets.…”