Molecular dynamics simulation of amorphization in forsterite by cosmic rays

Journal Article · Fri Feb 16 00:00:00 EST 2007 · Nuclear Instruments and Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms, 255(1):172-176

DOI:https://doi.org/10.1016/j.nimb.2006.11.021· OSTI ID:901163

Devanathan, Ram; Durham, Philip; Du, Jincheng; Corrales, Louis R; Bringa, Eduardo M

We have examined cosmic ray interactions with silicate dust grains by simulating a thermal spike in a 1.25 million atom forsterite (Mg2SiO4) crystal with periodic boundaries. Spikes were generated by giving a kinetic energy of 1 or 2 eV to every atom within a cylinder of radius 1.73 nm along the [001] direction. An amorphous track of radius ~3 nm was produced for the 2 eV/atom case, but practically no amorphization was produced for 1 eV/atom because of effective dynamic annealing. Chemical segregation was not observed in the track. These results agree with recent experimental studies of ion irradiation effects in silicates, and indicate that cosmic rays can cause the amorphization of interstellar dust.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 901163
• Report Number(s): PNNL-SA-55042; 3564; 8208; KC0201020; TRN: US200720%%356
• Journal Information: Nuclear Instruments and Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms, 255(1):172-176, Vol. 255, Issue 1
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMORPHOUS STATE
ANNEALING
ATOMS
COSMIC RADIATION
DUSTS
INTERSTELLAR GRAINS
IRRADIATION
KINETIC ENERGY
MAGNESIUM SILICATES
MOLECULAR DYNAMICS METHOD
SEGREGATION
SILICATES
SIMULATION
THERMAL SPIKES
cosmic ray interactions
interstellar dust
amorphization
silicate
forsterite
molecular dynamics simulation
Environmental Molecular Sciences Laboratory