Mechanism of selective desorption of atoms from the CdWO4 crystal surface during heating and ion bombradment in vacuum

The charge in CdWO4 surface composition during its heating in vacuum and also during heating combined with ion bombardment is studied. Relative voncentrations of components on the surface were determined by the RES method according to the ratio of areas of W4f7/2,5/2; Cd3d5/2; 01S lines, taking into account ionization cross sections of the shells. Dependences of the change in surface composition on irradiation dose by 500 eV argon ions in the temperature range from 20 to 600 deg C are obtained. It is shown that Cd is the most easily sputtered component. Processes of component desorption from the surface are considered from the viewpoint of electron mechanism of ion crystal evaporation. 4 refs.; 3 figs