Nuclear orientation of14N after grazing collisions with a silicon surface

The nuclear orientation of¹⁴N is investigated after the scattering of¹⁴N⁺ ions with energies ranging from 7 to 350 keV from an Si(111)-surface under grazing angles of incidence. For projectile energies above 50 keV, we find a constant nuclear orientationP ₁=〈I _z 〉/I∼22%, whereas towards lower energiesP _I shows a pronounced decrease. Our measurements provide important information in the application of surface scattering to obtain nuclear polarized beams.