https://doi.org/10.1140/epjst/e2013-02016-9
Regular Article
Experiments on screening effect in deuteron fusion reactions at extremely low energies
1 Institute of Physics, University of Szczecin, Wielkopolska 15, Szczecin, Poland
2 Institut fur Optik ind Atomare Physik, Technische Universitat Berlin, Berlin, Germany
3 Institute for Solid-State Nuclear Physics, Berlin, Germany
4 TRIUMF, Vancouver, Canada
5 Institut fur Physik, Humboldt-Universitat zu Berlin, Berlin, Germany
a e-mail: natalia.targosz@wmf.univ.szczecin.pl
Received: 8 June 2013
Revised: 9 August 2013
Published online: 23 October 2013
The enhanced electron screening effect in nuclear reactions taking place in dense astrophysical plasmas is extremely important for determination of stellar reaction rates in terrestrial laboratories as well as in prediction of cross sections enhancement in interiors of stars such as White and Brown Dwarfs or Giant Planets. This effect resulting in reduction of the nuclear Coulomb potential by the atomic electrons has been confirmed in many laboratory experiments. Unfortunately, experimental screening energies are much higher than the theoretical predictions and the reason for that remains unknown. Here, we present absorbing results of the experiment studying d + d nuclear reactions in different deuterized metallic targets under ultra high vacuum conditions. The total cross sections and angular distributions of the 2H(d,p)3H and 2H(d,n)3He reactions have been measured using a deuteron beam of energies between 8 and 30 keV provided by the electron cyclotron ion source. The atomic cleanness of the target surface has been secured by combining Ar sputtering of the target and Auger electrons spectroscopy. Due to application of an on-line analysis method, the homogeneity of the implanted deuteron densities could be continuously monitored. We will discuss probable causes of the large discrepancy between theoretical and experimental data.
© EDP Sciences, Springer-Verlag, 2013