Astrophysical S-factor of T(4He, γ)7Li reaction at E cm = 15.7 keV
- 41 Downloads
The astrophysical S-factor of the reaction T(4He, γ)7Li is measured for the first time at the center of mass energy E cm = 15.7 keV, lower than the energy range of the Standard Big Bang Nucleosynthesis (SBBN) model. The experiment is performed on a Hall pulsed accelerator (TPU, Tomsk). An acceleration pulse length of 10 μs allows one to suppress the background of cosmic radiation and the ambient medium by five orders of magnitude. A beam intensity of ~ 5 × 1014 4He+ ions per pulse allows one to measure an extremely low reaction yield. The yield of γ-quanta with the energies E γ 0 = 2483.7 keV and E γ 1 = 2006.1 keV is registered by NaI(Tl) detectors with the efficiency ε = 0.331 ± 0.026. A method for direct measurement of the background from the chain of reactions T(4He, 4He)T→T(T, 2n)X→(n, γ) and/or (n, n′γ) which ends by neutron activation of materials surrounding the target is proposed and implemented in this study. The value of the astrophysical S-factor of the reaction T(4He, γ)7Li S αt (E cm = 15.7 keV) = 0.091 ± 0.032 keV b provides the choice from the set of experimental data for the astrophysical S αt -factor in favor of experimental data  with S αt (E cm = 0) = 0.1067 ± 0.0064 keV b.
Unable to display preview. Download preview PDF.
- 17.R. B. Firestone and V. S. Shirley, Table of Isotopes, 8th ed. (Wiley, New York, 1998).Google Scholar
- 22.E. L. Trykov and I. R. Svinin, “Analysis and reevaluation of the neutron cross sections for 23Na,” INDC(CCP) (IAEA, 2000), Vol. 425Google Scholar
- 23.H. Makii, Y. Nagai, K. Mishima, et al., “Neutroninduced reactions using a γ-ray detector in a 12C(α, γ)16O reaction study,” Phys. Rev. C 76, 022801(R) (2007).Google Scholar
- 26.Libraries ENDF/B-VII.1, IAEA Nuclear Data Services. www-nds.iaea.org/endf.Google Scholar
- 27.V. M. Bystritsky and F. M. Pen’kov, “Analytic estimates of the product yields for nuclear reaction in the ultralow energy range,” Phys. At. Nucl. 66, 76 (2003).Google Scholar
- 28.M. M. Filipowicz, V. M. Bystritsky, G. N. Dudkin, F. M. Penk’ov, and A. V. Philippov “Monte Carlo simulations of dd reaction parameters study at ultra-low energy range using plasma Hall accelerator and deuterized targets,” Int. J. Mod. Phys. E 21, 1250089 (2012).Google Scholar