ION-BEAM INTERACTION WITH INSULATING CRYSTALS - STUDIES ON KH2PO4 ANDNH4H2PO4

Different damage effects are observed in KDP and ADP when irradiated w ith light and heavy ion beams. Color centres stable up to 240 K are ob served in both compounds irradiated with beams of 22MeV H-2(+) and flu ences below 1x10(16)ions/cm(2); a tentative mechanism for their genera tion is given. For fluences between 1x10(16) and 2x10(16) ions/cm(2) n o further damage is observed in KDP; but ADP crystals show a light col or stable up to the melting point and for higher fluences they appear white and opaque: X-ray diffraction patterns show no amorphization; a broad band due to electronic excitations, besides the characteristic R aman spectra is observed. No spontaneous cleavage was ever observed. W ith 88 MeV O-16(6+) ions, as dense valence-electronic and nuclear inte ractions become important, clustering of point defects and creation of extended defects take place; different damage steps appear progressiv ely, including radiation induced spontaneous cleavage; threshold fluen ces are given.