Simulation of the Ion Modification Processes in the Silicate Dust of Protoplanetary Disks

The modification of crystalline olivine under irradiation with 1.43-MeV deuterons was studied experimentally. For the first time, the partial destruction of olivine in the surface (100–200 nm) layer was found at a current density of 5–10 A/cm². This effect is caused by ionization and desorption of Mg and Fe atoms at deuteron fluences (3–8 × 10¹⁶cm^–2) which are substantially below the amorphization threshold. It was suggested that the negative charge of the anion group SiO₄ ^4–is neutralized by the interaction with the deuterium ions and Frenkel pairs. The mechanism of sputtering of the crystalline olivine surfaces under irradiation with H, D, He, and Ar ions was studied using of the TRIM 98 program.