The 3He(τ, α)2p reaction at 9.11, 7.88 and 6.9 MeV

Production of high energy deuterons in the reaction:3He+3He?4He+2H+e ++v

“…The assumption of approximate energy independence of the cross section as done by Bardin et al [4] is inadequate. The 2p production cross section exhibits a pronounced diffraction like structure as a function of angle and the maxima and minima shift with bombarding energy both in their position and magnitude [6]. For example the first minimum in Fig.…”

“…As the 3He gas pressure in the target could only be maintained at a maximum of about 9 torr a slit system was specially designed to increase the geometry factor of the detectors used in this correlation experiment. By looking for the e-d coincidences rather than for the deuterons alone, and by choosing an appropriate angle of detection for the 2p pairs near the peak of d (7 the ~vsO curve for the 3He+3He~4He+p+p reaction [6], it was possible to enhance the production of 2p pairs at low relative momenta and their decay products, while the energies and masses of the reaction products could be determined by making particle identification with a A E -E telescope. The 3He gas used in the ion source of the accelerator as well as the target in our experiment, was guaranteed to have a tritium content of less than one part in 1011 by its manufacturer M/S Monsanto Chemical Corporation.…”

“…10 of Ref. 6 evolves from a rather sharp one at 0cm~42 ~ to a broad one stretching from 0cm=40 ~ to 0cm~52 ~ for a change in Ela b from 9.1 MeV to 6.9 MeV. Davies et al I-4] measured the angular distribution of the reaction 3He(3He,4He)2p at E~ab=25MeV and got a maximum cross section ~ 1 mb/sr at 0cm=40 ~ Ro-berts et al [7] measured the differential cross section for the same reaction at El, b= 32 MeV and got a maximum near 0cm=40 ~ with a magnitude of 7 mb/sr.…”

Final-state interactions

“…They were obtained over a very extended energy range allowed by the experimental techniques, demonstrating that they were dominated at forward angles by the nucleonnucleon pole. T h e culmination of the series of experiments at Berkeley on these reactions was a remeasurement of spectra with very high statistical accuracy by Slobodrian et al (1970) and Meiner et al (1969). T h e analysis was performed considering two extreme cases: (i) when the spectra were fully determined by the showing the dominance of a direct mechanism from SH(d, 3He)2n.…”

“…Experimental evidence proved both opinions not valid in general. At 11.96 MeV (3.27) was studied by indicating a small p-p enhancement Slobodrian et al (1970). studied this reaction at 9.72, 8.46 and 7.6 MeV (figure40), measuring extensive energy and angular distributions of the 4He and proton spectra.Figure 41.…”