Počet záznamů: 1
New Determination of the H-2(d,p)H-3 and H-2(d,n)He-3 Reaction Rates at Astrophysical Energies
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SYSNO ASEP 0429047 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název New Determination of the H-2(d,p)H-3 and H-2(d,n)He-3 Reaction Rates at Astrophysical Energies Tvůrce(i) Tumino, A. (IT)
Sparta, R. (IT)
Spitaleri, C. (IT)
Mukhamedzhanov, A. M. (US)
Typel, S. (DE)
Pizzone, R. G. (IT)
Tognelli, E. (IT)
Degl'Innocenti, S. (IT)
Burjan, Václav (UJF-V) RID, ORCID, SAI
Kroha, Václav (UJF-V) RID
Hons, Zdeněk (UJF-V) RID, ORCID
La Cognata, M. (IT)
Lamia, L. (IT)
Mrázek, Jaromír (UJF-V) RID, ORCID, SAI
Piskoř, Štěpán (UJF-V) RID
Moroni, P. G. P. (IT)
Rapisarda, G. G. (IT)
Romano, S. (IT)
Sergi, M. L. (IT)Celkový počet autorů 19 Zdroj.dok. Astrophysical Journal - ISSN 0004-637X
Roč. 785, č. 2 (2014), s. 96Poč.str. 17 Forma vydání Tištěná - P Jazyk dok. eng - angličtina Země vyd. GB - Velká Británie Klíč. slova nuclear reactions ; nucleosynthesis ; abundances ; primordial nucleosynthesis ; stars: pre-main sequence Vědní obor RIV BG - Jaderná, atomová a mol. fyzika, urychlovače CEP LC07050 GA MŠMT - Ministerstvo školství, mládeže a tělovýchovy GAP203/10/0310 GA ČR - Grantová agentura ČR Institucionální podpora UJF-V - RVO:61389005 UT WOS 000335736800015 DOI 10.1088/0004-637X/785/2/96 Anotace The cross sections of the H-2(d,p)H-3 and H-2(d,n)He-3 reactions have been measured via the Trojan Horse method applied to the quasi-free H-2(He-3, p(3)H)H-1 and H-2(He-3,n(3)He)H-1 processes at 18 MeV off the proton in He-3. For the first time, the bare nucleus S(E) factors have been determined from 1.5 MeV, across the relevant region for standard Big Bang nucleosynthesis, down to the thermal energies of deuterium burning in the pre-main-sequence (PMS) phase of stellar evolution, as well as of future fusion reactors. Both the energy dependence and the absolute value of the S(E) factors deviate by more than 15% from the available direct data and existing fitting curves, with substantial variations in the electron screening by more than 50%. As a consequence, the reaction rates for astrophysics experience relevant changes, with a maximum increase of up to 20% at the temperatures of the PMS phase. From a recent primordial abundance sensitivity study, it turns out that the H-2(d,n)He-3 reaction is quite influential on Li-7, and the present change in the reaction rate leads to a decrease in its abundance by up to 10%. The present reaction rates have also been included in an updated version of the FRANEC evolutionary code to analyze their influence on the central deuterium abundance in PMS stars with different masses. The largest variation of about 10%-15% pertains to young stars (<= 1 Myr) with masses >= 1 M-circle dot. Pracoviště Ústav jaderné fyziky Kontakt Markéta Sommerová, sommerova@ujf.cas.cz, Tel.: 266 173 228 Rok sběru 2015
Počet záznamů: 1