Anomalous x-ray yields under surface wave resonance during reflection highenergy electron diffraction and adatom site determination

In L x-ray emissions from a Si(111)-root 3 x root 3-In surface induced by e lectron beam irradiation were measured as functions of the incident glancin g angle. Under surface wave resonance conditions, anomalous x-ray intensiti es were clearly observed. Using dynamical calculations, these intensities a re well explained as changes in density of the electron wave field at adato m positions. From these intensities, the adatom site was analyzed, and it w as found that the T-4 model is better than the H-3 model.