Kossel interferences of proton-induced AlKα radiation

Kossel interferences of AlKα radiation are observed, using a 900 keV proton beam to excite fluorescence radiation inside a CuAl2 single crystal. The observed contrast of the (110)-AlKαsub(1,2) line, being unusually high (about 25 %), is remarkable. This large value and the dark-light structure of the line are discussed. An interpretation is given in terms of a recent theoretical treatment of the Kossel effect in a mosaic crystal, taking into account the small background by proton beam excitation. (author)