Compaction of porous ices rich in water by swift heavy ions

Photochemistry and desorption induced by X-rays in water rich astrophysical ice analogs: implications for the moon Enceladus and other frozen space environments

“…The evolution of OHdb (O-H dangling band in the cavities of water-rich ices) as a function of ice processing by radiation have been studied extensively in the literature. 31,[51][52][53][54][55] This band, centered around 3650 cm À1 , is very sensitive to the density of ices (porous contents) since is attributed to water molecules partially bounded inside cavities or pores in the ices. 55 Pilling et al, 31 evaluating the decreasing of OHdb feature as a function of uence, have determined the compaction cross section in a similar ice (H 2 O : CO : NH 3 ) mixture at low temperature during bombardment with swi ions (46 MeV Ni +13 ).…”

“…The OHdb in an important band in the spectrum of astrophysical ices because it might reveal the degree of compaction of such ices that might be linked with processing by radiation (momentum transfer) or by thermal annealing (energy transfer). 51,[55][56][57][58]…”

Radiolysis and sputtering of carbon dioxide ice induced by swift Ti, Ni, and Xe ions

“…This effect is related to a change of optical properties e.g. due to the compaction of the initially porous amorphous ice as discussed in [16,17] for water ice: at low temperature (about 10 K), a porous amorphous ice phase is obtained by accretion of water molecules, which is getting compacted under ion irradiation. Finally, it evolves towards a compact non-porous, but disordered amorphous phase.…”

Valine Radiolysis by H+, He+, N+, and S15+ MeV Ions

“…The ratio A v (0)/A v (F) describes compaction effects, and also explains why the different precursor bands do not evolve proportionally to each other as fluence increases. For compaction, it was found empirically that [39,40]:…”