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Hi Michael,<br>
<br>
I'm pretty sure the second to last column in SpeciesList.dat is the
spin part of the nuclear partition function. This is needed for
equilibrium calculations and for computing inverse rates properly.
I'm unsure about the last column, which is 0.5 for neutrons and
protons and zero otherwise.<br>
<br>
Nominally you can't just add species there. You also have to
include reactions. The currently working nuclear reaction network
in flash is "approx 13" (documented in "the flash paper" Fryxell et
al 2000 (<a href="http://adsabs.harvard.edu/abs/2000ApJS..131..273F">2000ApJS..131..273F</a>)
), which only treats the 13 nuclides He4, C12, O16, Ne20, Mg24,
Si28, S32, Ar36, Ca40, Ti44, Cr48, Fe52, and Ni56. These are
connected by capture/release of an alpha particle (He4 nucleus),
though the network uses approximate "effective" rates that account
for other side-channel reactions. This is the network used in
CellularDetonation. Very useful for explosive burning in
supernovae, x-ray bursts, and other thermonuclear transient stellar
phenomena. Not so useful for deuterium/tritium fusion.<br>
<br>
Dean<br>
<br>
<br>
<div class="moz-cite-prefix">On 05/23/2013 01:12 AM, Michael Sabino
wrote:<br>
</div>
<blockquote
cite="mid:CAH85JoHtEJSiaOHi8q23O1M_m1Jf0oyBN-+eGOaFaa4zNmEZsw@mail.gmail.com"
type="cite">
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<div>
<div>
<div>
<div>Hi,<br>
<br>
</div>
<div>I would like to introduce myself to this group.
My name is Michael Sabino, and I am drawn here due
to my fascination of simulations of
fusion+hydro+grav+... on computers.<br>
<br>
</div>
<div>First things first, and my first goal is to
simulate something I can understand, and then
hopefully get across to others.<br>
</div>
<div><br>
</div>
I'd looked at SpeciesList.txt to add deuterium,
tritium, and helium-4 to simulate detonation in those
materials (primarily to familiarize myself with some
aspects of FLASH), and I believe I've added them
correctly, but I get some unexpected results.<br>
<br>
</div>
The main question is: What are the last and 2nd to last
fields in the SpeciesList.txt that are identified with
"??" in the Simulation_initSpecies.F90 comment? Are they
important?<br>
<br>
</div>
<div>The model I am using is a modified version of
CellularDetonation, where I added deuterium and tritium
in place of carbon-12 and attempted to detonate a 50:50
mixture of it.<br>
<br>
</div>
The spurious results I wasn't expecting were issues with
the density in the grid cells showing up as a very low
number and erroring out to stdout. So low, that it was
below the smlrho and nuclearDensMin settings. I had to
lower those. The low values of density presumably have
something to do with the low temperature and density
fusion requirements of DT and DD, which I configured in my
upstream temperature and density profile in flash.par.
After disabling useShockBurn and doing the above, it
seemed to be proceeding without errors (albeit slowly,
since it was evaluating the fusion routines a lot more),
but I'll keep you up-to-date.<br>
<br>
<br>
</div>
Thanks,<br>
</div>
Michael Sabino<br>
</div>
<a moz-do-not-send="true"
href="mailto:Michael.Rocco.Sabino@gmail.com">Michael.Rocco.Sabino@gmail.com</a><br>
</div>
</blockquote>
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