Activation measurement of the3He(4He,?)7Be reaction

Abstract

The energy integrated absolute cross section of the 3He(4He, v)VBe reaction has been determined by an activation measurement, using the branching of the 7Be 53.44 d 1% decay to the 478 keV state in VLi and its subsequent v-decay. Depending on the branching ratio used (10.4% or 15.4%) we obtain a zero-energy nuclear cross section factor of S(0) = 0.56 _+ 0.03 keV. barn or S(0) = 0.38 + 0.03 keV. barn, respectively.

Synthesis of the elements in stars: forty years of progress

“…While the energy dependence of these models is in good agreement with the energy dependence of the measured cross sections, it would be useful to carry out a theoretical study of how robust this energy dependence is for a wider range of models. Osborne et al (1982Osborne et al ( ,1984 0.63 Ϯ 0.04 Robertson et al (1983) 0.56 Ϯ 0.03 Volk et al (1983) Weighted mean=0.579 Ϯ 0.024 a As extrapolated using the direct-capture model of Tombrello and Parker (1963). b As renormalized by Hilgemeier et al (1988).…”

Activation measurement of the reaction cross section at high energies

“…Several experimental studies followed this pioneering work in the next decades aiming at the determination of the 3 He(α, γ) 7 Be cross section at energies as low as possible in order to approach the astrophysically relevant energy range [4,5,6,7,8,9,10,11]. This energy range, the so called Gamow window, lies between about 15 and 30 keV at 15 MK temperature relevant for the solar core.…”

Comparison of the LUNA3He(α, γ)7Be activation results with earlier measurements and model calculations

“…Table 3 shows the resulting S(0) values for the different activation experiments. The measurement of Volk et al [18] is omitted since in that experiment only the energy integrated cross section has been determined. As one can see, there is a perfect agreement between the S(0) values obtained by the two recent, high precision experiments carried out by Nara Singh et al and the LUNA collaboration.…”