Experimental and theoretical screening energies for the 2H(d, p)3H reaction in metallic environments

Abstract

The study of the 2 H(d, p) 3 H reaction at very low energies in deuterized metallic targets provides a unique possibility to test models of the electron screening developed for dense astrophysical plasmas. Here, we compare the experimental screening energies obtained by our group as well as by other authors for different target materials with theoretical predictions based on an improved dielectric function theory. The calculations are performed within the self-consistent regime and include polarization of both quasifree and bound electrons. Additionally, the cohesion screening, arising from different binding energies of deuterons and α-particles in crystal lattices, is taken into account. The proposed theory predicts only a weak material dependence of the screening energy in agreement with our experimental results but fails in the absolute strength of the effect by a factor of 2. The projectile-velocity dependence of the screening energy corresponding to the transition from the weak-screening regime to the strong-screening limit is discussed.

Absence of low-temperature dependence of the decay ofBe7andAu198Kumar1, Hass2, Nir-El3 et al. 2008Phys. Rev. C233110View full textAdd to dashboardCite

“…For α-decay, the half-life of 210 Po in Cu metal at T = 12 K was measured to be shorter by 6.3 ± 1.4% as compared to room temperature [12]. However, such effects could not be confirmed by other experiments to the accuracy level of parts of a percent [13,14,15,16].…”

“…Furthermore, even within the Debye-Hückel screening model itself, the explicit temperature dependence of U D -the Coulomb energy of the Debye cloud -of the form 1/ √ T , is valid only for temperatures much higher than the Fermi temperature, E F , being of the order of thousands of degrees for Cu [15,17,18]. Below the Fermi temperature (certainly for 293 K and lower), there should be no temperature dependence.…”

Enhanced d(d,p)t cross section in metallic environments

“…In order to verify the expected Debye enhancement, all metals of groups 3 and 4 and the lanthanides have been studied at T = 200 • C (for details see [4]), where it was expected that the solubility reduced to a few percent and a large screening became observable. As was observed by Huke et al (reference therein [11]): "...the higher the deuteron density, the lower the screening value".…”

Meson Screening Masses in Thermal QCD

“…A new subtraction procedure is invented to get an UV finite result. It is a numerical approach, which requires the analytical form of the mesonic spatial correlation functions in the free case [2] in order to calculate the divergent integrals. Results are compared to the recent QCD lattice results [4,5].…”

“…To get a finite results for G(z) one has to regularize integrals. For the non interacting QGP the problem was solved for all mesonic channels in [2] adopting adopting Pauli-Villars regularization scheme. In the interacting case the problem is much more complicated since the meson spectral function is obtained only numerically and one has to adopt a numerical regularization.…”