Electron screening in d(d, p)t for deuterated metals: temperature effects

Abstract

The electron screening in the d(d, p)t reaction has been studied for the deuterated metal Pt at a sample temperature T = 20 • C-340 • C and for Co at T = 20 • C and 200 • C. The enhanced electron screening decreases with increasing temperature, where the data agree with the plasma model of Debye applied to the quasi-free metallic electrons. The data represent the first observation of a temperature dependence of a nuclear cross section. We also measured the screening effect for the deuterated metal Ti (an element of group 4 of the periodic table) at T = −10 • C-200 • C: above 50 • C, the hydrogen solubility dropped to values far below 1 and a large screening effect became observable. Similarly, all metals of groups 3 and 4 and the lanthanides showed a solubility of a few per cent at T = 200 • C (compared to T = 20 • C) and a large screening also became observable. Within the Debye model, the deduced number of valence electrons per metallic atom agrees with the corresponding number from the Hall coefficient, for all metals investigated.

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

“…The issue of the possible dependence of β-decay and electron-capture (EC) rates of radioactive nuclei on the nature and temperature of the host matrix and environment is a long standing subject [1,2]. Numerous recent experiments have claimed that the half-life of radioactive nuclei embedded in metals would be significantly affected by screening of the electrons in the metal and this effect further be strengthened at low temperatures [3,4,5,6,7]. Several of the most recent articles cite a longer half-life for the EC of 7 Be (0.8 ± 0.2% [8]) and a shorter half-life for the β + -decay of 22 Na (1.2±0.2% [9]), where these nuclides were implanted in the metals Pd and In and cooled to T = 12 K. For the β − -decay of 198 Au in a Au metallic environment the half-life was observed to be longer by 0.4 ± 0.7% at room temperature and by 4.0 ± 0.7% when the metal was cooled to T = 12 K, both compared to the literature value of the half-life [10].…”

Catalysis of Nuclear Reactions by Electrons

“…The effect is important in astrophysical scenarios, where almost all nuclear reactions happen at low energies and nuclei are not alone in the stellar plasma. The predicted effect was confirmed experimentally, but its measured magnitude was very often way above predictions [2][3][4][5][6][7][8][9][10][11]. Although the theory predicts an independence of electron screening on the nuclear surroundings, measurements of the same reactions in different environments gave different magnitudes of electron screening.…”

The role of correlation entropy in nuclear fusion in liquid lithium, indium and mercury

“…Attempts to explain the experimental results in Sendai [1,2,3], in Bochum and Gran Sasso [4,5,6,7,8,9], and in Berlin [10,12,11] are based on:…”