Coherent resonance contributions in the reactionsLi6(d,α)He4

Abstract

The angular distribution of the reaction 6 Li͑d , ␣͒ 4 He at deuteron energies below 100 keV and the total cross section as well as the angular distribution of the reaction 10 B͑d , p 0 ͒ 11 B at energies below 350 keV have been measured. Based on our experimental results and data of other authors, the reaction mechanism has been studied in a wide energy range, relevant for astrophysical applications. It has been found that in both cases broad resonances in the compound nuclei play the key role for the description of the excitation functions. The long-standing problems of describing the angular distributions could be solved for both reactions by assuming a coherent superposition between resonant and direct reaction amplitudes. A theoretical approach allowing for coherent calculations has been developed. Some astrophysical implications are discussed.

Measurement of astrophysical S factors and electron screening potentials for d(d, n)3He reaction In ZrD2, TiD2, D2O, and CD2 targets in the ultralow energy region using plasma accelerators

“…; Z 1 , Z 2 , μ are incident particle charges and reduced mass in a.e.m., respectively; S b (E) is astrophysical S factor for the reaction between "bare" nuclei at the collision energy of E. At present there are experimental data substantiating relative increase of dd-reaction cross section that occurs in deuterium-filled targets (gas targets and deuterated metals) as well as in some dielectrics and insulators at deuteron collision energy of 1.6-10 keV [9,[16][17][18][19][20][21][22][23][24][25]. ES effect was also observed and taken into account when studying d 3 He and d 6 Li reactions [17,[26][27][28][29] at deuterons and He (Li) collision energies of 2-13.8 keV (10.0-65.0 keV for d 6 Li reaction). In particular, the effect of ES is taken into account to extract correctly the parameters of a wide 2 + resonance of the compound nucleus, which contributes to the cross section of d 6 Li reactions at low energies [29].…”

“…ES effect was also observed and taken into account when studying d 3 He and d 6 Li reactions [17,[26][27][28][29] at deuterons and He (Li) collision energies of 2-13.8 keV (10.0-65.0 keV for d 6 Li reaction). In particular, the effect of ES is taken into account to extract correctly the parameters of a wide 2 + resonance of the compound nucleus, which contributes to the cross section of d 6 Li reactions at low energies [29].…”

First experimental evidence of D(p, γ)3He reaction in titanium deuteride in ultralow collision energy region

“…The obtained results of the studied reactions (1a) (1b) in the last decade [1][2][3][4][5][6][7][8][9][10], show the existence of an enhancement effect in the reaction of dd synthesis in deuteride metals, resulting from the presence of elec tron screening of deuterium nuclei. To verify the exist ence of this effect we have conducted experiments with beams of deuterons accelerated by a pulse Hall accelerator and using targets with deuterides of tita nium, zirconium and tantalum [8][9][10].…”

“…In the recent time, there has been an increase in the interest in the study of the mechanism of reaction between light nuclei (pd, dd) in metals saturated by hydrogen isotopes in the range of ultralow energies [1][2][3][4][5][6][7][8][9][10].…”

Reanalysis of the astrophysicalS(E) factors of the6Li(d,α)4He,7Li(p,α)4He and6Li(p,α)3He reactions

“…In this work, based on the hypothesis that the screening effects are independent of the isotopic effects and the fact that the screening effects depend on the environments, we reanalyze the experimental data of the 6 Li(d,α) 4 He, 7 Li(p,α) 4 He and 6 Li(p,α) 3 He reactions obtained by other groups [11,[19][20][21][22][23][24][25][26][27][28] in the high-and low-energy region, simultaneously. A polynomial energy dependence form is involved in our reanalysis process to fit the astrophysical S bare (E) factor of each reaction, and the parameters in this polynomial form are varied together with other parameters and U s provided by the environments (LiF solid targets and molecular H 2 or D 2 gas targets) to fit the experimental data of the 6 Li(d,α) 4 He, 7 Li(p,α) 4 He and 6 Li(p,α) 3 He reactions in high-and low-energy region, simultaneously.…”