[meteorite-list] ON POSSIBLE SOLAR ORIGIN OF METEORITIC NANODIAMONDS

[Starsinthedirt at aol.com]

Very interesting!  Thanks Shawn for the  post.

Tom

In a message dated 5/14/2010 11:28:14 P.M. Mountain  Daylight Time, 
photophlow at yahoo.com writes:
Hello Listers,

The next  few days ill be posting articles that pertain to the topic of  
nanodiamonds.

First up: 

ON POSSIBLE SOLAR ORIGIN OF  METEORITIC NANODIAMONDS 

Galina K. Ustinova ,Institute of Geochemistry  and Analytical Chemistry, 
Russian Academy of Sciences, Moscow V-334, 119991  Russia; E-mail: 
ustinova at dubna.net.ru 

The laboratory experiments  on synthesis of artificial nanodiamonds 
demonstrate an extremely large spectrum  of the physical and chemical conditions 
for realization of this process. Indeed,  the synthetic nanodiamonds are 
obtained in the processes of detonation synthesis  at high pressure and 
temperature, as well as by low-pressure condensation being  similar to chemical vapor 
deposition at moderate temperatures (CVD-techniques),  and as well as by 
irradiation of carbonaceous materials with laser, intensive  ultraviolet 
radiation or high-energy particles [1]. In view of the variety of  the admissible 
astrophysical conditions, one may anticipate ubiquitous  distributions of 
nanodiamonds in cosmos. Thus, the observations of the  interstellar 
extinction testify to the fact that up to 10% of the interstellar  carbon could be 
bound up in the interstellar diamond [2]. Nanodiamonds with the  lognormal 
size distribution being similar to that for meteoritic ones are  observed
in circumstellar disks in the systems of Herbig emission stars of  HD97048 
and Elias 1 [3], in the carbon-enriched protoplanetary nebulae [4] an  
n in the interplanetary dust [5]......

Of course, it cannot be  excluded that, somewhere at the periphery of the 
collapsing protosolar nebula,  some presolar grains of other generation could 
sur-vive and even preserve the  noble gases of their astro-physical 
sources. According to the estimates of [12],  the relative abundance in chondrites 
of presolar nanodiamonds generated in the  atmospheres of AGB stars amounts 
to ~1% only, and that
d at SNII explosions  is <  0.1%.

http://www.lpi.usra.edu/meetings/lpsc2010/pdf/1050.pdf

Shawn  Alan
eBayshop
http://shop.ebay.com/photophlow/m.html?_nkw=&_armrs=1&_from=&_ipg=&_trksid=p
4340
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