The3He(d,p) α reaction at astrophysical energies

Measurements of the D+D Reaction in Ti Metal with Incident Energies between 4.7 and 18 keV

“…In order to see the difference of the screening effects, more accurate experimental data are required as well as data at lower incident energies. The ratios of the yield of the D(d, p)T reaction to that of the D(d, n) 3 He reaction were obtained down to E d = 6.4 keV in the present work. It was found that the ratios stay constant at about 1.0 up to E d = 20 keV, and then decreases above 20 keV.…”

“…Experimental Results He-particles, tritons and protons, respectively, emitted in the D + D reaction. As shown in the figure, the 3 He peak is clearly seen at E d =15.4keV, while at E d = 6.4keV large backgrounds caused by electric noise compete with the peak, because the reaction cross section drops about three orders of magnitude in this energy range. Yields of 3 He and t were obtained for each bombarding energy by subtracting the background yields at the peak regions.…”

“…5, the ratio of the yield of the D(d, p)T to that of the D(d, n) 3 He reaction is plotted against incident energies (with open circles), together with the data (with squares and diamonds) by Krauss et al 7) The previous data show the tendency that the proton emission overcomes the neutron emission as decreasing the incident energy. The present data at around 15 keV are consistent with the previous ones, and the data below 15 keV down to 6.4 keV show that the ratio is almost 1.0.…”

“…Protons, tritons and 3 He particles emitted in the D(d, p)t and D(d, n) 3 He reactions occurring in TiDx plate were detected with two silicon detectors (thickness-area: 200mm-150mm 2 and 500 mm-200 mm 2 ) which were placed at about 2.5 cm from the target and at ± 135° in respect to the beam direction. In order to prevent δ-electrons and scattered deuterons from hitting the detectors directly, a 50 µg/cm 2 -thick carbon foil was placed in front of each detector.…”

“…Recently, in several reactions with light nuclei, such as the 3 He + d, 6,7 Li + d and 6,7 Li + p reactions, the deduced astrophysical S-factors for very low energies were found to be larger than those extrapolated from higher energy data. 1,2) The deviation seems to occur below the incident energy of about 20 keV for the 3 He + d reaction and about 80 keV for the Li+p,d reactions; corresponding classical closest distances at theses energies are 140 and 70 fm, respectively. Therefore, nuclei which sit each other in the distance farther than about 100 fm might experience a weaker repulsive potential than the Coulomb potential between the two bare nuclei.…”