A compilation of charged-particle induced thermonuclear reaction rates

Thermonuclear reaction rates V

https://escholarship.org/content/qt2dj9p3h4/qt2dj9p3h4.pdf?t=pmi3bw

ENDF/B-VIII.0: The 8th Major Release of the Nuclear Reaction Data Library with CIELO-project Cross Sections, New Standards and Thermal Scattering Data

For interpreting fusion rate measurements in present fusion experiments and predicting the fusion performance of future devices or of d-t experiments in present devices, it is important to know the fusion cross-sections as precisely as possible. Usually, it is not measured data that are used, but parametrizations of the cross-section as a function of the ion energy and parametrizations of the Maxwellian reactivity as a function of the ion-temperature. Since the publication of the parametrizations now in use, new measurements have been made and evaluations of the measured data have been improved by applying R-matrix theory. The authors show that the old parametrizations no longer adequately represent the experimental data and present new parametrizations based on R-matrix calculations for fusion cross-sections and Maxwellian reactivities for the reactions D(d,n)3He, D(d,p)T, T(d,n)4He and 3He(d,p)4He

https://iopscience.iop.org/article/10.1088/0029-5515/32/4/I07/pdf

Improved formulas for fusion cross-sections and thermal reactivities

Energy levels of light nuclei A=8,9,10

Low-energy fusion cross sections of D + D and D + 3He reactions

Stellar reaction rate of 14N(p, γ)15O and hydrogen burning in massive stars☆

The capture reaction4He(12C, γ)16O (E
cm= 134–338 MeV) as well as the elastic scattering process4He(12C,12C)4He (E
cm=144–338 MeV) have been investigated with the use of an intense12C beam and a windowless and4He recirculating gas target system The measurements involved two large NaI(T1) crystals in close geometry to an extended gas target, whereby angle-integrated γ-ray yields were obtained A large area plastic detector was used for the suppression of time-independent background A search for cascade γ-ray transitions was carried out by coincidence techniques The measurement of absolute cross sections is also reported Theoretical fits of the excitation function for the groundstate γ-ray transition requireE1 as well asE2 capture amplitudes, which are of equal importance at stellar energies This result increases significantly the stellar burning rate of4He(12C, γ)16O and leads to16O as the dominant product at the end of helium burning in massive stars The observed capture yield to the 692 MeV state is dominated by the direct capture mechanism and plays a small role at stellar energies

The4He(12C, γ)16O reaction at stellar energies

The 12C(α, γ)16O cross section at stellar energies

The capture reaction3He(α,γ)7Be has been investigated in the energy range ofEc.m. =107 to 1,266 keV. The4He or3He beams of up to 300 μA particle current were incident on3He or4He gas targets, respectively. The gas target systems were all of the windowless and recirculating type. Excitation functions have been obtained with the use of an extended-static gas target, while the measurements ofγ-ray angular distributions involved a quasi-point supersonic jet system. The determination of absolute cross sections has been carried out with both types of gas target systems. Theγ-ray yields in the3He(α,γ)7Be reaction were detected using 80 cm3 Ge(Li) detectors. The data lead to a zero-energy intercept of the astrophysicalS(E) factor ofS(0)=0.30±0.03 keV-b. This result reduces the calculated solar neutrino rate by a factor of 1.76.

H.W. Becker

Papers

Low-energy fusion cross sections of D + D and D + 3He reactions

Stellar reaction rate of 14N(p, γ)15O and hydrogen burning in massive stars☆

The4He(12C, γ)16O reaction at stellar energies

The 12C(α, γ)16O cross section at stellar energies

The3He(α,γ)7Be reaction and the solar neutrino problem