Measurement of the absolute cross section of the 3He(4He, γ)7Be reaction at Ec.m. = 525 keV

Alexander, T.K.; Ball, G. C.; Lennard, W.N.; Geißel, H.; Mak, H. B.

doi:10.1016/0375-9474(84)90229-x

Cited by 72 publications

(83 citation statements)

References 20 publications

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“…The apparent discrepancy at 2σ between experiments that observe capture gamma rays from this process (Refs. [64][65][66][67][68][69]) and those that observe photons from the 7 Be decay (Refs. [69][70][71]) is well-known from discussions of the solar neutrino problem [72].…”

Section: He(d P) 4 Hementioning

confidence: 99%

Estimating reaction rates and uncertainties for primordial nucleosynthesis

2000

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We present a Monte Carlo method for direct incorporation of nuclear inputs in primordial nucleosynthesis calculations. This method is intended to remedy shortcomings of current error estimation, by eliminating intermediate data evaluations and working directly with experimental data, allowing error estimation based solely on published experimental uncertainties. This technique also allows simple incorporation of new data and reduction of errors with the introduction of more precise data. Application of our method indicates that previous error estimates on the calculated abundances were too large by as much as a factor of three. Since uncertainties in the BBN calculation currently dominate inferences drawn from light-element abundances, the re-estimated errors have important consequences for cosmic baryon density, neutrino physics, and lithium depletion in halo stars. Our direct method allows detailed discussion of the status of the nuclear inputs, by identifying clearly the places where improved cross section measurements would be most useful. 26.35.+c, 98.80.Ft

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Section: He(d P) 4 Hementioning

confidence: 99%

Estimating reaction rates and uncertainties for primordial nucleosynthesis

2000

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“…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.…”

Section: Introductionmentioning

confidence: 99%

Activation measurement of the reaction cross section at high energies

et al. 2013

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The astrophysically important 3 He(α, γ) 7 Be reaction was studied at high energies where the available experimental data are in contradiction. A thin window 3 He gas cell was used and the cross section was measured with the activation method. The obtained cross sections at energies between E c.m. = 1.5 and 2.5 MeV are compared with the available data and theoretical calculations. The present results support the validity of the high energy cross section energy dependence observed by recent experiments.

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“…Cross section measurements by the prompt γ-ray method [18,22,23,24,25,26,27] cover the energy range 1 An experiment based on a third method to measure the cross section, namely the detection of 7 Be nuclei in a recoil mass separator, is in progress at the ERNA facility [17]. E = 107-2500 keV, although with limited precision at low energies.…”

Section: Thementioning

confidence: 99%

“…Activation data: filled squares [18], filled diamonds [19], filled triangles [21], stars (present work). Prompt-γ data: triangles [23], inverted triangles [24], circles [25] (renormalized by a factor 1.4 [27]), squares [18], diamonds [26], crosses [27]. Dashed line: previously adopted R-matrix fit [8].…”

Section: E Parasiticmentioning

confidence: 99%

He3(α,γ)
Gyürky
¹
,
Confortola
²
,
Costantini
³

et al. 2007
Phys. Rev. C

102

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The flux of 7 Be and 8 B neutrinos from the Sun and the production of 7 Li via primordial nucleosynthesis depend on the rate of the 3 He(α,γ) 7 Be reaction. In extension of a previous study showing cross section data at 127 -167 keV center of mass energy, the present work reports on a measurement of the 3 He(α,γ) 7 Be cross section at 106 keV performed at Italy's Gran Sasso underground laboratory by the activation method. This energy is closer to the solar Gamow energy than ever reached before. The result is σ = 0.567±0.029stat ±0.016syst nbarn. The data are compared with previous activation studies at high energy, and a recommended S(0) value for all 3 He(α,γ) 7 Be activation studies, including the present work, is given.PACS numbers: 25.55.-e, 26.20.+f, 26.35.+c, 26.65.+t

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Measurement of the absolute cross section of the 3He(4He, γ)7Be reaction at Ec.m. = 525 keV

Cited by 72 publications

References 20 publications

Estimating reaction rates and uncertainties for primordial nucleosynthesis

Estimating reaction rates and uncertainties for primordial nucleosynthesis

Activation measurement of the reaction cross section at high energies

He3(α,γ)
Gyürky
¹
,
Confortola
²
,
Costantini
³

et al. 2007
Phys. Rev. C

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Measurement of the absolute cross section of the 3He(4He, γ)7Be reaction at Ec.m. = 525 keV

Cited by 72 publications

References 20 publications

Estimating reaction rates and uncertainties for primordial nucleosynthesis

Estimating reaction rates and uncertainties for primordial nucleosynthesis

Activation measurement of the reaction cross section at high energies

He3(α,γ)Gyürky1, Confortola2, Costantini3 et al. 2007Phys. Rev. C

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He3(α,γ)
Gyürky
¹
,
Confortola
²
,
Costantini
³

et al. 2007
Phys. Rev. C