Electronic Desorption from Internal Surfaces of Porous Low Temperature Ice

Details Electronic Desorption from Internal Surfaces of Porous Low Temperature Ice Electronic Desorption from Internal Surfaces of Porous Low Temperature Ice

May 2006

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006agusm.p23a..03g&link_type=abstract

American Geophysical Union, Fall Meeting 2007, abstract #P23A-03

Biology

5200 Planetary Sciences: Astrobiology, 5215 Origin Of Life, 5405 Atmospheres (0343, 1060), 5422 Ices, 5470 Surface Materials And Properties

Scientific paper

Radiation induced surface desorption from low temperature water ice plays a crucial role in the astrochemistry of icy planetary surfaces, comets and ice-covered interstellar grains. Excitations from low energy electrons (5- 100 eV) or VUV photons can hop between the strongly coupled hydrogen bonding network and migrate until they encounter a surface or a defect where they localize and induce dissociation. Ices deposited at very low temperatures, such as those in interstellar space, exhibit an exceptionally low density and have a highly porous amorphous structure. These pores represent large open structures and enclose a volume of vacuum and give the porous ice an enormous internal surface area. These pores are also likely to play an important role in spontaneous segregation of hydrophobic organic contaminants. The electronic structure of ice at the interface of these pores should resemble that of the outer surface vacuum interface. The effects of porosity and morphology of amorphous and crystalline D2O ices on the electron stimulated generation and trapping of D2 and O2 have been studied by post-irradiation thermal desorption. Molecular deuterium is released in the temperature range from 55 - 105 K for each of the samples, with two notable bursts at 115 and 132 K for porous amorphous ice. The majority of trapped O2 coevolves with desorption of the ice matrix, suggesting that clathrate hydrates may be important trapping sites. Production and trapping of organic polymers within pores from coadsorbed methane and ammonia are also discussed.

Affiliated with

Also associated with

No associations

Rating

Electronic Desorption from Internal Surfaces of Porous Low Temperature Ice does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Electronic Desorption from Internal Surfaces of Porous Low Temperature Ice, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electronic Desorption from Internal Surfaces of Porous Low Temperature Ice will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1024942