Differences

This shows you the differences between two versions of the page.

--- nu_rnet [2014/06/05 13:54]
schutrumpg
+++ nu_rnet [2014/06/05 16:52]
schutrumpg
@@ Line 1: / Line 1: @@
-**[Group 7]**
+======$\nu$Rnet======
-*** Group name:**  $\nu$Rnet
+=====Members:=====
-*** Members:**
+===Tony Ahn: Analysis person===
-Tony Ahn: Analysis person
+===Tsung-han Yeh: Parameter person===
-Tsung-han Yeh: Parameter person
+===Bastian Schuetrumpf: Code person===
-Bastian Schuetrumpf: Code person
+=====Motivation=====
-*** Motivation**
 It is possible that electron fraction Ye will affect the neutron density resulting in the abundance pattern of the r-process.
-{{:core-collapse_figure.png?500|}}
+{{:core-collapse_figure.png?650|}}
 Fig. Schematic representation of the evolutionary stages from stellar core collapse. (Ref. H.Th. Janka, arXiv:astro-ph/0612072)
-*** Method:**
+=====Method and aims:=====
 - To simulate r-process using x-net
@@ Line 27: / Line 25: @@
 - To find change of the r-process path and change of the abundance pattern
-*** Input Parameters:**
+=====Logbook=====
+====Input Parameters====
+===Density temperature trajectory===
 At first we had to set a reasonable temperature and density trajectory for a neutrino driven wind in which the r-process takes place. We take a realistic trajectory from Raphael Hix the temperature and density profile looks like this:
 {{ :out.jpg?500 |}}
+===$Y_e$===
+To set the initial electron fraction $Y_e$ which is equivalent to the proto fraction due to charge neutrality, we ran the nse version of the xnet code. This calculates the equilibrium initial abundances for a given electron fraction, density and temperature. Therefore the lines in the code tagged by !NSE have to be uncommented and the lines tagged by !NOTNSE have to be commented. This can be done quickly with the following commands in Unix:
+<code>
+sed -e 's/^\!\(.*\!NSE\)/ \1/' conditions.f90 >conditions.f90-
+sed -e 's/^\!\(.*\!NSE\)/ \1/' net_mpi.f90 >net_mpi.f90-
+sed -e 's/^\!\(.*\!NSE\)/ \1/' net.f90 >net.f90-
+sed -e 's/^\!\(.*\!NSE\)/ \1/' data_distribute_mpi.f90 >data_distribute_mpi.f90-
+mv conditions.f90- conditions.f90
+mv net_mpi.f90- net_mpi.f90
+mv net.f90- net.f90
+mv data_distribute_mpi.f90- data_distribute_mpi.f90
+sed -e 's/^\!\(.*\!NOTNSE\)/!\1/' net.f90 >net.f90-
+mv net.f90- net.f90
+</code>
+Additionally the line
+<code>NSE_OBJ = nse.o </code>
+in the Makefile has to be uncommented.
+It came out that at high Temperatures around 10 GK mainly free neutrons and free protons exist. The other abundances were found to be very low. Thus, for our final calculations we did not use the nse, but changed the proton fraction directly by varying the proton to neutron rate in the initial abundances and neglecting the all other abundances.
+===Reaction Network===
+Last but not least we need a reaction library. This was taken from the JINA Reaclib database. For the r-process only nucleides have to be considered which are stable or even more neutron rich. The proton rich nucleides can be neglected. In the chart of nuclei the considered rates look like this:
+{{ :nuclide_chart.jpg?650 |}}
+The black squares mark the stable isotopes.
+This network includes 4510 species and 53763 reaction rates. This setup requires a very fast matrix solver.
+===Matrix Solver===
+The standart matrix solver included in the xnet programm "LAPACK" is too slow to solve a network like this. Faster solutions are sparse matrix solver. Two interfaces are included in xnet: For MA48 and Pardiso. Instructions to include these matrix solvers in the code can be found in the documentation of the code. We experienced problems for both with Linux: Pardiso should be much faster than MA48 needs a full compiled LAPACK library. This is included in the ifort compiler. Finally we succeeded in compiling Pardiso version with ifort. The program can be found here.

Talent

User Tools

Site Tools

Differences

Page Tools