cool_dima.cpp

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/* This file is part of Cloudy and is copyright (C)1978-2022 by Gary J. Ferland and
 * others.  For conditions of distribution and use see copyright notice in license.txt */
/*CoolDima compute cooling due to level 2 lines */
/*ColStrGBar generate g-bar collision strengths for level 2 line2 */
#include "cddefines.h"
#include "taulines.h"
#include "dense.h"
#include "rt.h"
#include "doppvel.h"
#include "phycon.h"
#include "mewecoef.h"
#include "atoms.h"
#include "atmdat.h"
#include "thermal.h"
#include "cooling.h"

/*ColStrGBar generate g-bar collision strengths for level 2 line2 */
STATIC double ColStrGBar(const TransitionProxy::iterator& t , realnum cs1 );

void CoolDima(void)
{
        long int i, 
          ion,
          nelem;
        double cs;

        DEBUG_ENTRY( "CoolDima()" );

        /* no level2 command sets nWindLine to -1 */
        if( nWindLine<0 )
                return;

        static vector<realnum> DopplerWidth(LIMELM);
        for(nelem = ipHYDROGEN; nelem < LIMELM; ++nelem)
                DopplerWidth[nelem] = GetDopplerWidth(dense.AtomicWeight[nelem]);

        for( i=0; i < nWindLine; i++ )
        {
                ion = (*TauLine2[i].Hi()).IonStg();
                nelem = (*TauLine2[i].Hi()).nelem();

                if( (dense.lgIonChiantiOn[nelem-1][ion-1] && !atmdat.lgChiantiHybrid) ||
                                (dense.lgIonStoutOn[nelem-1][ion-1] && !atmdat.lgStoutHybrid) )
                {
                        /* If a species uses Chianti or Stout and hybrid is off, skip the level 2 lines */
                        continue;
                }
                // iso sequence ions are done elsewhere
                if( (*TauLine2[i].Hi()).IonStg() < (*TauLine2[i].Hi()).nelem()+1-NISO && 
                        // dense.maxWN is positive if hybrid chianti is turned on and this element is included
                        // in CloudyChianti.ini - zero otherwise
                         TauLine2[i].EnergyWN() >= dense.maxWN[nelem-1][ion-1])
                {
                        /* only evaluate cs if positive abundance */
                        if( dense.xIonDense[nelem-1][ion-1] > 0. )
                        {
                                /* now generate the collision strength */
                                cs = ColStrGBar(TauLine2.begin()+i , cs1_flag_lev2[i] );
                        }
                        else
                        {
                                cs = 1.;
                        }
                        /* now put the cs into the line array */
                        PutCS(cs,TauLine2[i] );
                        RT_line_one_escape( TauLine2[i], true,0.f, DopplerWidth[(*TauLine2[i].Hi()).nelem()-1] );
                        atom_level2(TauLine2[i] );
                        thermal.dima += TauLine2[i].Coll().cool();
                }
        }

        return;
}

/*ColStrGBar generate g-bar collision strengths for level 2 line2 */
STATIC double ColStrGBar(const TransitionList::iterator &t , realnum cs1 )
{
        long int i, 
          j;
        double ColStrGBar_v, 
          a, 
          b, 
          c, 
          d, 
          e1, 
          gb, 
          x, 
          y;
        double xx, 
          yy;

        DEBUG_ENTRY( "ColStrGBar()" );

        /* Calculation of the collision strengths of multiplets.
         * Neutrals are recalculated from 
         * >>refer cs   gbar    Fisher et al. (1996)
         * >>refer cs   gbar    Gaetz & Salpeter (1983, ApJS 52, 155) and 
         * >>refer cs   gbar    Mewe (1972, A&A 20, 215) 
         * fits for ions. */

        /* routine to implement g-bar data taken from
         *>>refer       cs      gbar    Mewe, R.; Gronenschild, E. H. B. M.; van den Oord, G. H. J., 1985,
         *>>refercon    A&AS, 62, 197 */

        /* zero hydrogenic lines since they are done by iso-sequence */
        if( (*(*t).Hi()).nelem() == (*(*t).Hi()).IonStg() )
        {
                ColStrGBar_v = 0.0;
                return( ColStrGBar_v );
        }

        /*was the block data linked in? */
        ASSERT( MeweCoef.g[1][0] != 0.);

        /* which type of transition is this? cs1 is the flag */

        /* >>chng 01 may 30 - cs1 < 0 means a forced collision strength */
        if( cs1 < 0. )
        {
                ColStrGBar_v = -cs1;
                return( ColStrGBar_v );
        }

        /* >>chng 99 feb 27, change to assert */
        ASSERT( cs1 >= 0.05 );

        /* excitation energy over kT */
        y = (*t).EnergyK()/phycon.te;
        if( cs1 < 1.5 )
        {
                xx = -log10(y);

                if( cs1 < 0.5 )
                {
                        yy = (1.398813573838321 + xx*(0.02943050869177121 + xx*
                          (-0.4439783893114510 + xx*(0.2316073358577902 + xx*(0.001870493481643103 + 
                          xx*(-0.008227246351067403))))))/(1.0 + xx*(-0.6064792600526370 + 
                          xx*(0.1958559534507252 + xx*(-0.02110452007196644 + 
                          xx*(0.01348743933722316 + xx*(-0.0001944731334371711))))));
                }

                else
                {
                        yy = (1.359675968512206 + xx*(0.04636500015069853 + xx*
                          (-0.4491620298246676 + xx*(0.2498199231048967 + xx*(0.005053803073345794 + 
                          xx*(-0.01015647880244268))))))/(1.0 + xx*(-0.5904799485819767 + 
                          xx*(0.1877833737815317 + xx*(-0.01536634911179847 + 
                          xx*(0.01530712091180953 + xx*(-0.0001909176790831023))))));
                }

                ColStrGBar_v = exp10(yy)*(*t).Emis().gf()/((*t).EnergyRyd() * 13.6);
        }
        else
        {
                i = (long int)cs1;

                if( i < 26 )
                {
                        e1 = log(1.0+1.0/y) - 0.4/POW2(y + 1.0);
                        a = MeweCoef.g[i-1][0];
                        b = MeweCoef.g[i-1][1];
                        c = MeweCoef.g[i-1][2];
                        d = MeweCoef.g[i-1][3];
                        x = (double)(*(*t).Hi()).nelem() - 3.0;

                        if( i == 14 )
                        {
                                a *= 1.0 - 0.5/x;
                                b = 1.0 - 0.8/x;
                                c *= 1.0 - 1.0/x;
                        }

                        else if( i == 16 )
                        {
                                a *= 1.0 - 0.9/x;
                                b *= 1.0 - 1.7/x;
                                c *= 1.0 - 2.1/x;
                        }

                        else if( i == 18 )
                        {
                                a *= 1.0 + 2.0/x;
                                b *= 1.0 - 0.7/x;
                        }

                        gb = a + (b*y - c*y*y + d)*e1 + c*y;

                        /*  ipLnRyd is exciation energy in Rydbergs */
                        ColStrGBar_v = 14.510395*(*t).Emis().gf()*gb/((*t).EnergyRyd() );
                        /* following i>=26 */
                }

                else
                {
                        /* 210 is the dimem of g, so [209] is largest val */
                        if( i < 210 )
                        {
                                j = (long)(MeweCoef.g[i-1][3]);
                                if( j == 1 )
                                {
                                        ColStrGBar_v = (*(*t).Lo()).g()*MeweCoef.g[i-1][0]*
                                          pow(phycon.te/exp10((double)MeweCoef.g[i-1][2]),(double)MeweCoef.g[i-1][1]);
                                }
                                else
                                {
                                        ColStrGBar_v = (*(*t).Lo()).g()*MeweCoef.g[i-1][0]*
                                          sexp(MeweCoef.g[i-1][1]*(exp10((double)MeweCoef.g[i-1][2])/
                                          phycon.te));
                                }
                        }

                        else
                        {
                                /* This is for AlII 1670 line only!
                                 *    ColStrGBar=0.0125*te**0.603 */
                                /* 98 dec 27, this is still in use */
                                ColStrGBar_v = 0.0125*phycon.sqrte*phycon.te10*
                                  phycon.te003;
                        }
                }
        }

        /* following to make sure that negative values not returned */
        ColStrGBar_v = MAX2(ColStrGBar_v,1e-10);
        return( ColStrGBar_v );
}