Influence of the Flux Peaking Effect on the DD Reaction Yield Upon D + Ion Channelling in Deuterated Palladium

The interaction between a deuterium ion (D + ) beam and deuterium-enriched Pd and Ti targets are studied using the HELIS ion accelerator (Lebedev Physical Institute). The neutron yield is determined from the DD reaction in the deuterated Pd target whose surface is irradiated with a D + -ion beam with an energy of 20 keV. The neutron flux is measured in the D + -ion-beam direction as a function of the angle β of target rotation relative to the beam axis using a multichannel detector based on 3 He counters. Significant anisotropy (orientation effect) of the neutron yield is observed; it is two times higher at β = 0° than at β = ±30°. The orientation effect can be associated with channeling and the so-called flux-peaking effect. It is studied by computer simulations using the BCM-2.0 code. The enhanced density of the D + flux between the (200) planes of a Pd crystal (where implanted D is located) at zero angle of incidence with respect to these planes makes it possible to qualitatively explain the observed orientation effect. No effect is observed in a homogeneous target of deuterated titanium.