Anomalous enhancement of DD reaction in Pd and Au/Pd/PdO heterostructure targets under low-energy deuteron bombardment

Yields of protons emitted in the D + D reaction in Pd, Au/ Pd/ PdO, Ti, and Au foils are measured by a dE - E counter telescope for bombarding energie s between 2.5 and 10 keV. The experimental yields are compared with those p redicted from a parametrization of the cross section and stopping power at higher energies. It is found that for Ti and Au target the enhancement of t he D( d, p) T reaction is similar to that observed with a deuterium gas tar get (several tens of eV). The dependence of the yields on the bombarding en ergy corresponds well to the screening potential parameters U-s = 250 +/- 1 5 eV for Pd and 601 +/- 23 eV for Au/Pd/PdO. Possible models of the enhance ment obtained are discussed. (C) 1998 American Institute of Physics. [S0021 -3640(98)00123- 6].