Nuclear Reaction Network Calculations: The Next

GenerationBrad Meyer

Clemson University

John C. Calhoun

Fort Hill

Anna Maria Calhoun

Thomas Clemson

Farmer’s Hall

Tillman Hall

Outline

• Brief introduction to reaction networks and nuclear data needs

• libnucnet as an example of a next generation nuclear network

• Concern: nuclear database

• Proposal: nuclear theory HUB

www.webnucleo.org/home/movies/alpha_rich/mpg/abundance_histogram.mpg

)0()( XetX

AXdt

dX

At

Computing the abundances (or probabilities)

How we do it: finite difference in time

)()()(

)()()(

)()()(

1 tXtAIttX

tXttXtAI

ttAXt

tXttX

Courtesy of Peter Moller

The full network

• >4000 nuclear species

• 73364 in the current JINA reaclib database (excluding any other special reactions)

www.webnucleo.org/home/movies/r_process/mpg/abund_rprocess.mpg

www.webnucleo.org/home/movies/r_process/mpg/qse_rprocess.mpg

libnucnet as an example of the next generation of reaction

networks

What is libnucnet?

• A C toolkit for storing and managing nuclear reaction network.

• Built on top of libxml (the gnome XML parser and toolkit) and gsl (the GNU scientific library).

• Released under the GNU General Public License.

• Available at http://www.webnucleo.org

History of libnucnet

• Original goal—online nucleosynthesis tool• Problem—input over the web• Solution—XML (eXtensible Markup Language)• Libxml as input and output• Libxml has powerful built-in data structures (lists,

hashes, trees, etc.)—build new nucleosynthesis code on top of libxml

• Hashes provide easy access to data—particularly useful for experimentalists

Features of libnucnet

• Intrinsically 3-d• Easily handles an arbitrary nuclear network (bbn to r-

process), including (any number of) isomeric states• Reactions are handled the way humans think about

them: “c12 + he4 o16 + gamma” or “o15 n15 + positron + neutrino_e”

• Hierarchically structured• Naturally uses xml as input (allows for schemas,

stylesheets, xpath selection, etc.)• Read and validate data across the web• Allows for user-supplied screening, NSE correction

factor functions, and rate fit functions.

Structure of libnucnet

• Libnucnet__Nuc.c/h: a collection of nuclei– Libnucnet__Species: a species– Libnucnet__Nuc: a collection of species

• Libnucnet__Reac.c/h: a collection of nuclear reactions– Libnucnet__Reaction: a reaction– Libnucnet__Reac: a collection of reactions

• Libnucnet.c/h: a network and a collection of zones– Libnucnet__Net: a Libnucnet__Nuc + Libnucnet__Reac– Libnucnet__Zone: a physical zone– Libnucnet: a network plus a collection of zones

XML Data for the nuclear collection<nuclear_data> <!--n--> <nuclide> <z>0</z> <a>1</a> <source>Tuli (2000)</source> <mass_excess>8.071</mass_excess> <spin>0.5</spin> <partf_table> <point> <t9>0.01</t9> <log10_partf>0</log10_partf> </point> <point> <t9>0.15</t9> <log10_partf>0</log10_partf> </point> </partf_table> </nuclide>…</nuclear_data>

XML Data for the nuclear collection (with states)

<!--al26--> <nuclide> <z>13</z> <a>26</a> <states> <state id="g"> <source>Tuli (2000) + Gupta and Meyer (2001)</source> <mass>-12.21</mass> <spin>5</spin> <partf_table> ... </partf_table> </state> <state id="m"> <source>Tuli (2000) + Gupta and Meyer (2001)</source> <mass>-11.982</mass> <spin>0</spin> <partf_table> ,,, </partf_table> </state> </states> </nuclide>

XML Data for Reactions—a rate table

<reaction_data>

<!-- h1 + n -> h2 + gamma -->

<reaction> <source>Smith et al. (1993)</source> <reactant>h1</reactant><reactant>n</reactant> <product>h2</product><product>gamma</product> <rate_table> <point> <t9>0.001</t9> <rate>4.6168E+04</rate> <sef>1.000</sef> </point> … </rate_table> </reaction> ….</reaction_data>

XML Data for Reactions—a single rate

<!-- o19 -> f19 + electron + anti-neutrino_e -->

<reaction> <source>Nuclear Data tables</source> <reactant>o19</reactant> <product>f19</product> <product>electron</product> <product>anti-neutrino_e</product> <single_rate>1.6251e-01</single_rate></reaction>

XML Data for Reactions—a non-smoker fit

<!– ne15 + n -> ne16 + gamma -><reaction> <source>ADNDT (2001) 75, 1 (non-smoker)</source> <reactant>ne15</reactant> <reactant>n</reactant> <product>ne16</product> <product>gamma</product> <non_smoker_fit> <Zt> 10</Zt> <At> 15</At> <Zf> 10</Zf> <Af> 16</Af> <Q> 8.071000</Q> <spint> 0.0000</spint> <spinf> 0.0000</spinf> <TlowHf>-1.0000</TlowHf> <Tlowfit> 0.0100</Tlowfit> <acc> 1.900000e-06</acc> <a1> 6.225343e+00</a1> <a2> 1.023384e-02</a2> <a3>-1.272184e+00</a3> <a4> 3.920127e+00</a4> <a5>-1.966720e-01</a5> <a6> 1.394263e-02</a6> <a7>-1.389816e+00</a7> <a8> 2.983430e+01</a8> </non_smoker_fit></reaction>

Zone data<zone_data>

<zone label1="x1" label2="y1" label3="z1"> <nuclide> <z>0</z> <a>1</a> <x>0.5</x> </nuclide> <nuclide name=“h1”> <x>0.5</x> </nuclide> </zone> …</zone_data>

ρi = 108 g/cc, τ=0.1 s, Ye = 0.417

26Mg(alpha,n)29Si rate x 3

Hoppe, BSM, et al. (2009)

Fedkin, BSM, and Grossman (2010)

Future of nuclear data for reaction network calculations

• Reaction data—JINA reaclib database in libnucnet xml format

• Nuclear data????

Where I’m headed

• Study nuclear network equilibria (NSE, QSE, etc.)libnuceq

• Build a multi-zone Galactic chemical evolution network on top of libnucnet.

nanoHUB.org

HUBzero

http://hubzero.org/tour

The HUBZero Consortium

Deploying a Tool

http://nanohub.org/resources/3863

Outline

• Brief introduction to reaction networks and nuclear data needs

• libnucnet as an example of a next generation nuclear network

• Concern: nuclear database

• Proposal: nuclear theory HUB