SURFACE TRAPPED X-RAYS - WHISPERING-GALLERY MODES AT LAMBDA=0.7-ANGSTROM

X-ray bound states trapped on a curved surface are realized by couplin g subangstrom photons at grazing angles into a bent silicon wafer with adjustable radius. At small radii of curvature the usual ray approxim ation breaks down and new phenomena associated with wave optical behav ior of x-ray surface eigenmodes are revealed. For such samples, tunnel ing is shown to extinguish all but the ground state surface eigenmode, whose presence may be detected after extremely long distances of prop agation along the surface.