changes_in_SNEC-1.01.tex

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\large \bf SNEC: The SuperNova Explosion Code
\normalsize \rm

Version 1.01 -- Changelog


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Changes between \texttt{SNEC-1.01} and \texttt{SNEC-1.00} are related
to the performance of the code only, while all the physics is the
same. \texttt{SNEC-1.01} is about a factor $\sim 2$ faster than
\texttt{SNEC-1.00}.

The technical improvements making the code faster include:

\begin{itemize}
\item Constructing opacity tables for each grid point from the OPAL
tables once at the beginning of the simulation, instead of calling the
OPAL routine at each time step. This is justified by the fact that
in the current version of \texttt{SNEC} the composition of the profile
does not change with time;

\item Optimization of matrix element calculation in
  \texttt{arrays.F90}. Thanks go to Brian W. Mulligan (University of
  Texas, Austin);

\item Optimization of \texttt{nickel.F90} and \texttt{simple\_saha.F90} routines.
\end{itemize}

Other small changes and fixes include:

\begin{itemize}
\item Fix in the mean lifetime and yield of $^{56}{\rm Co}$, the
  current values are taken from Nadyozhin, ApJS 92, 527 (1994);

\item Error message in the case when the number of grid points is not equal
 to the number of lines in \texttt{GridPattern.dat} (note that some machines
require a blank line at the end of the file to count the number of lines correctly);

\item Adding (optional) parameters \texttt{bomb\_mode} and \texttt{Ni\_by\_hand}. 

In the case when \texttt{bomb\_mode=1} (default), the parameter \texttt{final\_energy} 
corresponds to the asymptotic energy of the system, as in \texttt{SNEC-1.00}.
In the case when \texttt{bomb\_mode=2}, the parameter 
\texttt{final\_energy} corresponds to the thermal bomb energy.

In the case when \texttt{Ni\_by\_hand=1} (default), the mass fraction of $^{56}{\rm Ni}$ is
calculated from the parameters \texttt{Ni\_mass} and \texttt{Ni\_boundary\_mass} as
in \texttt{SNEC-1.00}. In the case when \texttt{Ni\_by\_hand=0}, the mass fraction of 
$^{56}{\rm Ni}$ is taken from the composition profile.

\end{itemize}

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