Berlin 2005 – wissenschaftliches Programm
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HK: Physik der Hadronen und Kerne
HK 6: Kern- und Teilchen-Astrophysik
HK 6.2: Vortrag
Freitag, 4. März 2005, 14:30–14:45, TU MA144
Electron screening in d(d,p)t for deuterated metals: temperature dependence — •Francesco Raiola — Inst. für Experimentalphysik III, Ruhr-Universität Bochum, Germany
The electron screening effect in the d(d,p)t reaction has been studied at the Ruhr-Universität Bochum for most of the metals and some insulators/semiconductors by using deuterated targets [1]. The deuterated targets were produced via implantation of low-energy deuterons. As compared to measurements performed with a gaseous D2 target, a large effect has been observed for all metals. In particular work has been done to investigate the high solubility for the metals of groups III and IV and the lanthanides, at a sample temperature T=200 ∘C. The hydrogen solubility in the samples dropped to a level of few percent (compared to T=20 ∘C) and a large screening became thus observable.
An explanation of the large effect in metals is provided by the plasma model of Debye applied to the quasi-free metallic electrons. A first evidence of the aplicability of Debye’s model is that the deduced number of free electrons per metallic atom agrees with the calculated number from the Hall coefficient [2], for all metals investigated.
A critical test of the classical Debye model is the temperature dependence Ue ∝ T−1/2. This temperature dependence measurement is in progress and new results will be presented.
Supported by BMBF(05CL1PC1/1), DFG(Ro429/31-1), and Dynamitron-Tandem-Laboratorium. [1]F.Raiola et al.: Eur. Phys. J.A19(2004)283; [2]C.M.Hurd: "The Hall effect in metals and alloys"; (Plenum Press, 1972).