Ion beam interaction with insulating crystals: Studies on KH sub(2)PO sub(4) and NH sub(4)H sub(2)PO sub(4)

Different damage effects are observed in KDP and ADP when irradiated with light and heavy ion beams. Color centres stable up to 240 K are observed in both compounds irradiated with beams of 22 MeV super(2)H super(+) and fluences below 1x10 super(16) ions/cm super(2); a tentative mechanism for their generation is given. For fluences between 1x10 super(16) and 2x10 super(16) ions/cm super(2) no further damage is observed in KDP; but ADP crystals show a light color 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 Raman spectra is observed. No spontaneous cleavage was ever observed. With 88 MeV super(16)O super(6+) ions, as dense valence-electronic and nuclear interactions become important, clustering of point defects and creation of extended defects take place; different damage steps appear progressively, including radiation induced spontaneous cleavage; threshold fluences are given.