Angular Distribution of the ReactionHe3(d, p)He4

Abstract

Monoergic deuterons from the Minnesota electrostatic generator were used to bombard a thin gaseous target of He 3 . Protons formed in the reaction He 3 (d,p)He i were detected outside the reaction chamber by a Nal scintillation counter. The cross section for the reaction He 3 (d,^)He 4 was measured between the angles of 15° and 130° in the laboratory at deuteron energies of 0.260, 0.455, 0.978, 1.51, 2.01, 2.50, 3.01, and 3.56 Mev. The cross section was measured at a fixed angle of 86° for deuteron energies from 240 kev to 914 kev. A maximum occurred at a deuteron energy of 430±30 kev. The cross section appears to be isotropic in the center-of-mass system in the neighborhood of the maximum. The value of the total cross section at the maximum is 0.90db0.10 barn. Comparison of this value with the upper bound provided by the single level dispersion formula indicates that the spin of the compound state of Li 5 formed in the reaction is f. At 978 kev there is a slight angular dependence of the cross section, which becomes more pronounced at higher energies. At 2.50 Mev the cross section displays a minimum at approximately 113°. At 3.01 Mev the minimum has shifted to 108°, and at 3.56 Mev it appears at 103°. * Supported by the joint program of the U. S. Office of Naval Research and the U. S. Atomic Energy Commission.t.

Energetic Protons and α Particles Emitted in 150-keV Deuteron Bombardment on Deuterated Ti

“…In this case the 3 He particle ejected in the primary reaction reacts with deuterons at rest in the target. However, the protons emitted in the secondary reaction cannot form a sharp peak, because of the spread of energy and direction of the 3 He. In order to verify this situation quantitatively, the spectral shape of the protons has been calculated for the sequential reaction.…”

“…1, the major reactions in the deuteron bombardment are the D+D → p+t (Q = 4.03 MeV) and the D+D → n+ 3 He (Q = 3.27 MeV) reactions. Although the secondary reactions of these reaction products have been naturally considered, no reactions can produce such high energy protons except for the D+ 3 He reaction.…”

“…For the broad bump observed between 12 and 16 MeV, protons are interpreted to be emitted in the D( 3 He, p) 4 He reaction (Q = 18.35 MeV) which sequentially occurs following the primary D(d, 3 He)n reaction. In this case the 3 He particle ejected in the primary reaction reacts with deuterons at rest in the target.…”

“…2 (a) does not show such increase since it was measured with a thick Al absorber. Figure 3 shows a scatter plot of ∆E vs. E measured at 135° in the bombardment on TiD x Tritons and 3 He particles emitted in the D + D reaction cannot punch through the ∆E detector. Protons from the D(d,p)T reaction as well as their pileups are seen as a heavy locus in the lowest part of the figure, although the low energy part of ∆E is cut, where a huge peak is expected at about (E, ∆E) = (850, 50) channels.…”

“…The characteristics of the high energy proton structure are these: a broad bump ranging from 12.5 to 16.5 MeV, a sharp peak at 14.1 MeV, and a continuum up to ~17 MeV where the bump and the peak are superimposed. The sharp peak was interpreted as protons emitted in the 3 He(d,p) 4 He (Q=18.35MeV) reaction, 1) since the peak energy just follows the kinematical prediction at detected angles of 90°, 110° and 135°; the interpretation requires an anomalous concentration of 3 He in the target before the bombardment began as discussed in ref.…”