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

From: Starsinthedirt at aol.com <Starsinthedirt_at_meteoritecentral.com>
Date: Sat, 15 May 2010 12:29:55 EDT
Message-ID: <6021e.269b3425.39202603_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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Received on Sat 15 May 2010 12:29:55 PM PDT