J/A+A/541/A158      7Li(p,α)4He reaction rate      (Lamia+, 2012)

Recent evaluation of the 7Li(p,α)4He reaction rate at astrophysical energies via the Trojan Horse method. Lamia L., Spitaleri C., La Cognata M., Palmerini S., Pizzone R.G. <Astron. Astrophys. 541, A158 (2012)> =2012A&A...541A.158L 2012A&A...541A.158L
ADC_Keywords: Atomic physics Keywords: nuclear reactions, nucleosynthesis, abundances - stars: abundances - stars: interiors Abstract: The charged-particle induced reactions on lithium have been studied by several works. In particular, several direct measurements of the 7Li(p,α)4He reaction have been performed to extrapolate its low-energy astrophysical S(E)-factor and evaluate the electron screening potential, Ue. In view of recent direct measurements, we discuss our estimate of the bare-nucleus S(E)-factor and an evaluation of the corresponding reaction rate. Moreover, we present the extracted electron screening potential. Description: The Trojan Horse method (THM) allows us to measure the 7Li(p,α)4He bare-nucleus S(E)-factor down to energies of ∼10keV, rendering unnecessary the extrapolation procedure typically used by the direct measurements. The 7Li(p,α)4He S(E)-factor is deduced from the 2H(7Li,α4He)n reaction by selecting the quasi-free contribution to the reaction yield. The plane-wave impulse approximation has proved an effective approach as distortions appear negligible. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table2.dat 61 60 Adopted and the evaluated Torjan Horse (TH) 7Li(p,α)4He reaction rate -------------------------------------------------------------------------------- Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 6 F6.3 GK T9 Temperature (in 109K) 8- 15 E8.3 --- b_Rate Lower value for TH 7Li(p,α)4He reaction rate 17- 24 E8.3 --- Rate Adopted value for TH 7Li(p,α)4He reaction rate 26- 33 E8.3 --- B_Rate Upper value for TH 7Li(p,α)4He reaction rate 35- 42 E8.3 --- Rate.fit Fitted value for TH 7Li(p,α)4He reaction rate 44- 51 E8.3 --- Rate.N99 Nacre (Angulo et al. 1999, Nucl. Phys. A, 656, 3) value for 7Li(p,α)4He reaction rate 53- 56 F4.2 --- Adopt/N99 Ratio Adopted-to-Nacre values 58- 61 F4.2 --- Adopt/fit Ratio Adopted-to-Fit values -------------------------------------------------------------------------------- History: From electronic version of the journal
(End) Patricia Vannier [CDS] 23-Apr-2012
The document above follows the rules of the Standard Description for Astronomical Catalogues; from this documentation it is possible to generate f77 program to load files into arrays or line by line